From 0b17bf59304e723b6813d661b85c71cf30e83165 Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 30 Mar 2021 00:46:59 -0700
Subject: [PATCH 01/18] Brought slice() in line with select() indexing, without
 wrapping.  Replaced a lot of select() and slice() calls with last(),
 list_head(), and list_tail() calls.

---
 arrays.scad              | 130 ++++++++++++++++++++++++++-------------
 attachments.scad         |   2 +-
 beziers.scad             |   2 +-
 debug.scad               |   2 +-
 gears.scad               |  10 +--
 hull.scad                |   2 +-
 joiners.scad             |   2 +-
 math.scad                |  12 ++--
 modular_hose.scad        |   4 +-
 paths.scad               |  44 ++++++-------
 quaternions.scad         |   2 +-
 regions.scad             |   2 +-
 rounding.scad            |  57 +++++++++--------
 screws.scad              |   2 +-
 shapes.scad              |   4 +-
 shapes2d.scad            |  28 ++++-----
 skin.scad                |  26 ++++----
 strings.scad             |   2 +-
 tests/test_arrays.scad   |  57 +++++++++++------
 tests/test_geometry.scad |  16 ++---
 tests/test_math.scad     |   2 +-
 threading.scad           |   4 +-
 turtle3d.scad            |   6 +-
 vnf.scad                 |  18 +++---
 24 files changed, 250 insertions(+), 186 deletions(-)

diff --git a/arrays.scad b/arrays.scad
index e4de121..7d85d8c 100644
--- a/arrays.scad
+++ b/arrays.scad
@@ -53,13 +53,12 @@ function _same_type(a,b, depth) =
 
 
 // Function: select()
+// Topics: List Handling
 // Description:
 //   Returns a portion of a list, wrapping around past the beginning, if end<start. 
 //   The first item is index 0. Negative indexes are counted back from the end.
 //   The last item is -1.  If only the `start` index is given, returns just the value
 //   at that position.
-// Topics: List Handling
-// See Also: slice(), subindex(), last()
 // Usage:
 //   item = select(list,start);
 //   list = select(list,start,end);
@@ -67,6 +66,7 @@ function _same_type(a,b, depth) =
 //   list = The list to get the portion of.
 //   start = The index of the first item.
 //   end = The index of the last item.
+// See Also: slice(), subindex(), last()
 // Example:
 //   l = [3,4,5,6,7,8,9];
 //   a = select(l, 5, 6);   // Returns [8,9]
@@ -97,33 +97,36 @@ function select(list, start, end) =
 
 
 // Function: slice()
-// Usage:
-//   list = slice(list,start,end);
 // Topics: List Handling
-// See Also: select(), subindex(), last()
+// Usage:
+//   list = slice(list,s,e);
 // Description:
-//   Returns a slice of a list.  The first item is index 0.
-//   Negative indexes are counted back from the end.  The last item is -1.
+//   Returns a slice of a list, from the first position `s` up to and including the last position `e`.
+//   The first item in the list is at index 0.  Negative indexes are counted back from the end.
+//   An index of -1 refers to the last list item.
 // Arguments:
-//   list = The array/list to get the slice of.
-//   start = The index of the first item to return.
-//   end = The index after the last item to return, unless negative, in which case the last item to return.
+//   list = The list to get the slice of.
+//   s = The index of the first item to return.
+//   e = The index of the last item to return.
+// See Also: select(), subindex(), last()
 // Example:
-//   a = slice([3,4,5,6,7,8,9], 3, 5);   // Returns [6,7]
+//   a = slice([3,4,5,6,7,8,9], 3, 5);   // Returns [6,7,8]
 //   b = slice([3,4,5,6,7,8,9], 2, -1);  // Returns [5,6,7,8,9]
-//   c = slice([3,4,5,6,7,8,9], 1, 1);   // Returns []
-//   d = slice([3,4,5,6,7,8,9], 6, -1);  // Returns [9]
+//   c = slice([3,4,5,6,7,8,9], 1, 1);   // Returns [4]
+//   d = slice([3,4,5,6,7,8,9], 5);      // Returns [8,9]
 //   e = slice([3,4,5,6,7,8,9], 2, -2);  // Returns [5,6,7,8]
-function slice(list,start,end) =
-    assert( is_list(list), "Invalid list" )
-    assert( is_finite(start) && is_finite(end), "Invalid number(s)" )
-    let( l = len(list) )
-    l==0
-      ? []
-      : let(
-            s = start<0? (l+start) : start,
-            e = end<0? (l+end+1) : end
-        ) [for (i=[s:1:e-1]) if (e>s) list[i]];
+//   f = slice([3,4,5,6,7,8,9], 4, 3;    // Returns []
+function slice(list,s=0,e=-1) =
+    assert(is_list(list))
+    assert(is_int(s))
+    assert(is_int(e))
+    !list? [] :
+    let(
+        l = len(list),
+        s = constrain(s + (s<0? l : 0), 0, l-1),
+        e = constrain(e + (e<0? l : 0), 0, l-1)
+    )
+    [if (e>=s) for (i=[s:1:e]) list[i]];
 
 
 // Function: last()
@@ -367,7 +370,7 @@ function list_decreasing(list) =
 // Usage:
 //   list = repeat(val, n);
 // Topics: List Handling
-// See Also: list_range()
+// See Also: range(), rangex()
 // Description:
 //   Generates a list or array of `n` copies of the given value `val`.
 //   If the count `n` is given as a list of counts, then this creates a
@@ -387,37 +390,36 @@ function repeat(val, n, i=0) =
     [for (j=[1:1:n[i]]) repeat(val, n, i+1)];
 
 
-// Function: list_range()
+// Function: range()
 // Usage:
-//   list = list_range(n=, <s=>, <e=>);
-//   list = list_range(n=, <s=>, <step=>);
-//   list = list_range(e=, <step=>);
-//   list = list_range(s=, e=, <step=>);
+//   list = range(n, <s=>, <e=>);
+//   list = range(n, <s=>, <step=>);
+//   list = range(e=, <step=>);
+//   list = range(s=, e=, <step=>);
 // Topics: List Handling
-// See Also: repeat()
 // Description:
 //   Returns a list, counting up from starting value `s`, by `step` increments,
 //   until either `n` values are in the list, or it reaches the end value `e`.
 //   If both `n` and `e` are given, returns `n` values evenly spread from `s`
 //   to `e`, and `step` is ignored.
 // Arguments:
-//   ---
 //   n = Desired number of values in returned list, if given.
+//   ---
 //   s = Starting value.  Default: 0
 //   e = Ending value to stop at, if given.
 //   step = Amount to increment each value.  Default: 1
+// See Also: repeat(), rangex()
 // Example:
-//   a = list_range(4);                  // Returns [0,1,2,3]
-//   b = list_range(n=4, step=2);        // Returns [0,2,4,6]
-//   c = list_range(n=4, s=3, step=3);   // Returns [3,6,9,12]
-//   d = list_range(n=5, s=0, e=10);     // Returns [0, 2.5, 5, 7.5, 10]
-//   e = list_range(e=3);                // Returns [0,1,2,3]
-//   f = list_range(e=7, step=2);        // Returns [0,2,4,6]
-//   g = list_range(s=3, e=5);           // Returns [3,4,5]
-//   h = list_range(s=3, e=8, step=2);   // Returns [3,5,7]
-//   i = list_range(s=4, e=8.3, step=2); // Returns [4,6,8]
-//   j = list_range(n=4, s=[3,4], step=[2,3]);  // Returns [[3,4], [5,7], [7,10], [9,13]]
-function list_range(n, s=0, e, step) =
+//   a = range(4);                  // Returns [0,1,2,3]
+//   b = range(n=4, step=2);        // Returns [0,2,4,6]
+//   c = range(n=4, s=3, step=3);   // Returns [3,6,9,12]
+//   d = range(n=5, s=0, e=10);     // Returns [0, 2.5, 5, 7.5, 10]
+//   e = range(e=3);                // Returns [0,1,2,3]
+//   f = range(e=7, step=2);        // Returns [0,2,4,6]
+//   g = range(s=3, e=5);           // Returns [3,4,5]
+//   h = range(s=3, e=8, step=2);   // Returns [3,5,7]
+//   i = range(s=4, e=8.3, step=2); // Returns [4,6,8]
+function range(n, s=0, e, step) =
     assert( is_undef(n) || is_finite(n), "Parameter `n` must be a number.")
     assert( is_undef(n) || is_undef(e) || is_undef(step), "At most 2 of n, e, and step can be given.")
     let( step = (n!=undef && e!=undef)? (e-s)/(n-1) : default(step,1) )
@@ -428,6 +430,50 @@ function list_range(n, s=0, e, step) =
         [for (v=[s:step:e]) v] ;
     
 
+// Function: rangex()
+// Usage:
+//   list = rangex(n, <s=>, <e=>);
+//   list = rangex(n, <s=>, <step=>);
+//   list = rangex(e=, <step=>);
+//   list = rangex(s=, e=, <step=>);
+// Topics: List Handling
+// Description:
+//   Returns a list, counting up from starting value `s`, by `step` increments, until
+//   either `n` values are in the list, or it reaches the value just before the end value `e`.
+//   If both `n` and `e` are given, returns `n` values evenly spread from `s` to the value
+//   just before `e`, and `step` is ignored.
+// Arguments:
+//   n = Desired number of values in returned list, if given.
+//   ---
+//   s = Starting value.  Default: 0
+//   e = Ending value to stop at, if given.
+//   step = Amount to increment each value.  Default: 1
+// See Also: repeat(), range()
+// Example:
+//   a = rangex(4);                  // Returns [0,1,2,3]
+//   b = rangex(5,e=1);              // Returns [0, 0.2, 0.4, 0.6, 0.8]
+//   c = rangex(n=4, step=2);        // Returns [0,2,4,6]
+//   d = rangex(n=4, step=0.25);     // Returns [0, 0.25, 0.5, 0.75]
+//   e = rangex(n=4, s=3, step=3);   // Returns [3,6,9,12]
+//   f = rangex(n=5, s=0, e=10);     // Returns [0, 2, 4, 6, 8]
+//   g = rangex(e=3);                // Returns [0,1,2]
+//   h = rangex(e=7, step=2);        // Returns [0,2,4,6]
+//   i = rangex(s=3, e=5);           // Returns [3,4]
+//   j = rangex(s=3, e=8, step=2);   // Returns [3,5,7]
+//   k = rangex(s=2, e=8, step=2);   // Returns [2,4,6]
+//   l = rangex(s=2, e=8.1, step=2); // Returns [2,4,6,8]
+function rangex(n, s=0, e, step) =
+    assert( is_undef(n) || is_finite(n), "Parameter `n` must be a number.")
+    assert( is_undef(n) || is_undef(e) || is_undef(step), "At most 2 of n, e, and step can be given.")
+    let( step = (n!=undef && e!=undef)? (e-s)/n : default(step,1) )
+    is_undef(e)
+      ? assert( is_consistent([s, step]), "Incompatible data.")
+        [for (i=[0:1:n-1]) s+step*i ]
+      : assert( is_vector([s,step,e]), "Start `s`, step `step` and end `e` must be numbers.")
+        let(steps=floor((e-s)/step+0.5))
+        [for (i=[0:1:steps-1]) s+step*i ];
+    
+
 
 // Section: List Manipulation
 
diff --git a/attachments.scad b/attachments.scad
index 04d8a17..0a283d1 100644
--- a/attachments.scad
+++ b/attachments.scad
@@ -442,7 +442,7 @@ function find_anchor(anchor, geom) =
     let(
         cp = select(geom,-3),
         offset = anchor==CENTER? CENTER : select(geom,-2),
-        anchors = select(geom,-1),
+        anchors = last(geom),
         type = geom[0]
     )
     is_string(anchor)? (
diff --git a/beziers.scad b/beziers.scad
index 79fe650..fb49adc 100644
--- a/beziers.scad
+++ b/beziers.scad
@@ -769,7 +769,7 @@ function path_to_bezier(path, closed=false, tangents, uniform=false, size, relsi
     )
     assert(min(sizevect)>0, "Size and relsize must be greater than zero")
     [
-        for(i=[0:lastpt-1])
+        for(i=[0:1:lastpt-1])
             let(
                 first = path[i],
                 second = select(path,i+1),
diff --git a/debug.scad b/debug.scad
index 6e4bdae..fccc6c9 100644
--- a/debug.scad
+++ b/debug.scad
@@ -377,7 +377,7 @@ module show_anchors(s=10, std=true, custom=true) {
         }
     }
     if (custom) {
-        for (anchor=select($parent_geom,-1)) {
+        for (anchor=last($parent_geom)) {
             attach(anchor[0]) {
                 if(two_d) {
                     anchor_arrow2d(s, color="cyan");
diff --git a/gears.scad b/gears.scad
index 5bff0fc..52ea9bd 100644
--- a/gears.scad
+++ b/gears.scad
@@ -960,11 +960,11 @@ function bevel_gear(
                 each apply(xflip() * zrot(360*tooth/teeth) * m, path3d(profile))
             ]
         ],
-        thickness = abs(verts1[0][0].z - select(verts1,-1)[0].z),
+        thickness = abs(verts1[0][0].z - last(verts1)[0].z),
         vertices = [for (x=verts1) down(thickness/2, p=reverse(x))],
         sides_vnf = vnf_vertex_array(vertices, caps=false, col_wrap=true, reverse=true),
-        top_verts = select(vertices,-1),
-        bot_verts = select(vertices,0),
+        top_verts = last(vertices),
+        bot_verts = vertices[0],
         gear_pts = len(top_verts),
         face_pts = gear_pts / teeth,
         top_faces =[
@@ -1431,8 +1431,8 @@ function worm_gear(
                 )
             ]
         ],
-        top_verts = select(profiles,-1),
-        bot_verts = select(profiles,0),
+        top_verts = last(profiles),
+        bot_verts = profiles[0],
         face_pts = len(tooth_profile),
         gear_pts = face_pts * teeth,
         top_faces =[
diff --git a/hull.scad b/hull.scad
index 5658bec..a7b73c7 100644
--- a/hull.scad
+++ b/hull.scad
@@ -158,7 +158,7 @@ function _hull_collinear(points) =
 //   %polyhedron(points=pts, faces=faces);
 function hull3d_faces(points) =
     assert(is_path(points,3),"Invalid input to hull3d_faces")
-    len(points) < 3 ? list_range(len(points))
+    len(points) < 3 ? range(len(points))
   : let ( // start with a single non-collinear triangle
           tri = noncollinear_triple(points, error=false)
         )
diff --git a/joiners.scad b/joiners.scad
index 8c0625d..2dd8175 100644
--- a/joiners.scad
+++ b/joiners.scad
@@ -968,7 +968,7 @@ module rabbit_clip(type, length, width,  snap, thickness, depth, compression=0.1
                       );
     assert(fullpath[4].y < fullpath[3].y, "Pin is too wide for its length");
     
-    snapmargin = -snap + select(sidepath,-1).x;// - compression;
+    snapmargin = -snap + last(sidepath).x;// - compression;
     if (is_pin){
       if (snapmargin<0) echo("WARNING: The snap is too large for the clip to squeeze to fit its socket")
       echo(snapmargin=snapmargin);
diff --git a/math.scad b/math.scad
index c63efb8..2297a29 100644
--- a/math.scad
+++ b/math.scad
@@ -495,7 +495,7 @@ function rand_int(minval, maxval, N, seed=undef) =
 function gaussian_rands(mean, stddev, N=1, seed=undef) =
     assert( is_finite(mean+stddev+N) && (is_undef(seed) || is_finite(seed) ), "Input must be finite numbers.")
     let(nums = is_undef(seed)? rands(0,1,N*2) : rands(0,1,N*2,seed))
-    [for (i = list_range(N)) mean + stddev*sqrt(-2*ln(nums[i*2]))*cos(360*nums[i*2+1])];
+    [for (i = range(N)) mean + stddev*sqrt(-2*ln(nums[i*2]))*cos(360*nums[i*2+1])];
 
 
 // Function: log_rands()
@@ -612,7 +612,7 @@ function _cumsum(v,_i=0,_acc=[]) =
         v, _i+1,
         concat(
             _acc,
-            [_i==0 ? v[_i] : select(_acc,-1)+v[_i]]
+            [_i==0 ? v[_i] : last(_acc) + v[_i]]
         )
     );
 
@@ -905,7 +905,7 @@ function _back_substitute(R, b, x=[]) =
     : let(
           newvalue = len(x)==0
             ? b[ind]/R[ind][ind]
-            : (b[ind]-select(R[ind],ind+1,-1) * x)/R[ind][ind]
+            : (b[ind]-list_tail(R[ind],ind+1) * x)/R[ind][ind]
       )
       _back_substitute(R, b, concat([newvalue],x));
 
@@ -1635,7 +1635,7 @@ function poly_mult(p,q) =
   is_undef(q) ?
     len(p)==2 
         ? poly_mult(p[0],p[1]) 
-    : poly_mult(p[0], poly_mult(select(p,1,-1)))
+    : poly_mult(p[0], poly_mult(list_tail(p)))
   :
   assert( is_vector(p) && is_vector(q),"Invalid arguments to poly_mult")
     p*p==0 || q*q==0
@@ -1678,7 +1678,7 @@ function _poly_div(n,d,q) =
 ///    or give epsilon for approximate zeros.  
 function _poly_trim(p,eps=0) =
     let( nz = [for(i=[0:1:len(p)-1]) if ( !approx(p[i],0,eps)) i])
-    len(nz)==0 ? [0] : select(p,nz[0],-1);
+    len(nz)==0 ? [0] : list_tail(p,nz[0]);
 
 
 // Function: poly_add()
@@ -1719,7 +1719,7 @@ function poly_roots(p,tol=1e-14,error_bound=false) =
     let( p = _poly_trim(p,eps=0) )
     assert( p!=[0], "Input polynomial cannot be zero." )
     p[len(p)-1] == 0 ?                                       // Strip trailing zero coefficients
-        let( solutions = poly_roots(select(p,0,-2),tol=tol, error_bound=error_bound))
+        let( solutions = poly_roots(list_head(p),tol=tol, error_bound=error_bound))
         (error_bound ? [ [[0,0], each solutions[0]], [0, each solutions[1]]]
                     : [[0,0], each solutions]) :
     len(p)==1 ? (error_bound ? [[],[]] : []) :               // Nonzero constant case has no solutions
diff --git a/modular_hose.scad b/modular_hose.scad
index 365bab3..0a878a1 100644
--- a/modular_hose.scad
+++ b/modular_hose.scad
@@ -169,9 +169,9 @@ module modular_hose(size, type, clearance=0, waist_len, anchor=BOTTOM, spin=0,or
     type=="segment"? concat(back(midlength,p=smallend),yflip(p=bigend))
   : type=="small" || type=="ball" ?
           concat(back(midlength,p=smallend),
-                 [[select(smallend,-1).x,0],[ smallend[0].x,0]])
+                 [[last(smallend).x,0],[ smallend[0].x,0]])
   : concat( back(midlength,p=bigend), 
-                  [[select(bigend,-1).x,0],[ bigend[0].x,0]]);
+                  [[last(bigend).x,0],[ bigend[0].x,0]]);
   bounds = pointlist_bounds(shape);
   center = mean(bounds);
   attachable(anchor,spin,orient,l=bounds[1].y-bounds[0].y, r=bounds[1].x)
diff --git a/paths.scad b/paths.scad
index 28858fa..d5ebae7 100644
--- a/paths.scad
+++ b/paths.scad
@@ -183,7 +183,7 @@ function path_length(path,closed=false) =
 function path_segment_lengths(path, closed=false) =
     [
         for (i=[0:1:len(path)-2]) norm(path[i+1]-path[i]),
-        if (closed) norm(path[0]-select(path,-1))
+        if (closed) norm(path[0]-last(path))
     ]; 
 
 
@@ -482,13 +482,13 @@ function path_chamfer_and_rounding(path, closed, chamfer, rounding) =
 				p2 = select(path,i),
 				crn1 = select(corner_paths,i-1),
 				crn2 = corner_paths[i],
-				l1 = norm(select(crn1,-1)-p1),
+				l1 = norm(last(crn1)-p1),
 				l2 = norm(crn2[0]-p2),
 				needed = l1 + l2,
 				seglen = norm(p2-p1),
 				check = assert(seglen >= needed, str("Path segment ",i," is too short to fulfill rounding/chamfering for the adjacent corners."))
 			) each crn2,
-			if (!closed) select(path,-1)
+			if (!closed) last(path)
 		]
 	) deduplicate(out);
 
@@ -783,16 +783,16 @@ function _path_fast_defragment(fragments, eps=EPSILON, _done=[]) =
     len(fragments)==0? _done :
     let(
         path = fragments[0],
-        endpt = select(path,-1),
+        endpt = last(path),
         extenders = [
             for (i = [1:1:len(fragments)-1]) let(
                 test1 = approx(endpt,fragments[i][0],eps=eps),
-                test2 = approx(endpt,select(fragments[i],-1),eps=eps)
+                test2 = approx(endpt,last(fragments[i]),eps=eps)
             ) if (test1 || test2) (test1? i : -1)
         ]
     ) len(extenders) == 1 && extenders[0] >= 0? _path_fast_defragment(
         fragments=[
-            concat(select(path,0,-2),fragments[extenders[0]]),
+            concat(list_head(path),fragments[extenders[0]]),
             for (i = [1:1:len(fragments)-1])
                 if (i != extenders[0]) fragments[i]
         ],
@@ -814,7 +814,7 @@ function _extreme_angle_fragment(seg, fragments, rightmost=true, eps=EPSILON) =
             for (i = idx(fragments)) let(
                 fragment = fragments[i],
                 fwdmatch = approx(seg[1], fragment[0], eps=eps),
-                bakmatch =  approx(seg[1], select(fragment,-1), eps=eps)
+                bakmatch =  approx(seg[1], last(fragment), eps=eps)
             ) [
                 fwdmatch,
                 bakmatch,
@@ -872,12 +872,12 @@ function assemble_a_path_from_fragments(fragments, rightmost=true, startfrag=0,
         // Found fragment is already closed
         [foundfrag, concat([path], remainder)]
     ) : let(
-        fragend = select(foundfrag,-1),
+        fragend = last(foundfrag),
         hits = [for (i = idx(path,e=-2)) if(approx(path[i],fragend,eps=eps)) i]
     ) hits? (
         let(
             // Found fragment intersects with initial path
-            hitidx = select(hits,-1),
+            hitidx = last(hits),
             newpath = list_head(path,hitidx),
             newfrags = concat(len(newpath)>1? [newpath] : [], remainder),
             outpath = concat(slice(path,hitidx,-2), foundfrag)
@@ -1239,17 +1239,17 @@ module path_spread(path, n, spacing, sp=undef, rotate_children=true, closed=fals
 {
     length = path_length(path,closed);
     distances = is_def(sp)? (
-        is_def(n) && is_def(spacing)? list_range(s=sp, step=spacing, n=n) :
-        is_def(n)? list_range(s=sp, e=length, n=n) :
-        list_range(s=sp, step=spacing, e=length)
+        is_def(n) && is_def(spacing)? range(s=sp, step=spacing, n=n) :
+        is_def(n)? range(s=sp, e=length, n=n) :
+        range(s=sp, step=spacing, e=length)
     ) : is_def(n) && is_undef(spacing)? (
         closed?
-            let(range=list_range(s=0,e=length, n=n+1)) list_head(range) :
-            list_range(s=0, e=length, n=n)
+            let(range=range(s=0,e=length, n=n+1)) list_head(range) :
+            range(s=0, e=length, n=n)
     ) : (
         let(
             n = is_def(n)? n : floor(length/spacing)+(closed?0:1),
-            ptlist = list_range(s=0,step=spacing,n=n),
+            ptlist = range(s=0,step=spacing,n=n),
             listcenter = mean(ptlist)
         ) closed?
             sort([for(entry=ptlist) posmod(entry-listcenter,length)]) :
@@ -1333,7 +1333,7 @@ function path_cut_points(path, dists, closed=false, direction=false) =
 function _path_cut_points(path, dists, closed=false, pind=0, dtotal=0, dind=0, result=[]) =
     dind == len(dists) ? result :
     let(
-        lastpt = len(result)==0? [] : select(result,-1)[0],       // location of last cut point
+        lastpt = len(result)==0? [] : last(result)[0],       // location of last cut point
         dpartial = len(result)==0? 0 : norm(lastpt-select(path,pind)),  // remaining length in segment
         nextpoint = dists[dind] < dpartial+dtotal  // Do we have enough length left on the current segment?
            ? [lerp(lastpt,select(path,pind),(dists[dind]-dtotal)/dpartial),pind] 
@@ -1419,7 +1419,7 @@ function _path_cuts_dir(path, cuts, closed=false, eps=1e-2) =
 function path_cut(path,cutdist,closed) =
   is_num(cutdist) ? path_cut(path,[cutdist],closed) :
   assert(is_vector(cutdist))
-  assert(select(cutdist,-1)<path_length(path,closed=closed),"Cut distances must be smaller than the path length")
+  assert(last(cutdist)<path_length(path,closed=closed),"Cut distances must be smaller than the path length")
   assert(cutdist[0]>0, "Cut distances must be strictly positive")
   let(
       cutlist = path_cut_points(path,cutdist,closed=closed),
@@ -1433,7 +1433,7 @@ function path_cut(path,cutdist,closed) =
           cutlist[i][0]==cutlist[i+1][0] ? []
           :
           [ if (!approx(cutlist[i][0], select(path,cutlist[i][1]))) cutlist[i][0],
-            each slice(path, cutlist[i][1], cutlist[i+1][1]),
+            each slice(path, cutlist[i][1], cutlist[i+1][1]-1),
             if (!approx(cutlist[i+1][0], select(path,cutlist[i+1][1]-1))) cutlist[i+1][0],
           ],
       [
@@ -1553,7 +1553,7 @@ function subdivide_path(path, N, refine, closed=true, exact=true, method="length
                 lerp(path[i],select(path,i+1), j/(add[i]+1))
             ]
         ],
-        closed? [] : [select(path,-1)]
+        closed? [] : [last(path)]
     );
 
 
@@ -1575,7 +1575,7 @@ function path_length_fractions(path, closed=false) =
                 norm(select(path,i+1)-path[i])
         ],
         partial_len = cumsum(lengths),
-        total_len = select(partial_len,-1)
+        total_len = last(partial_len)
     ) partial_len / total_len;
 
 
@@ -1603,10 +1603,10 @@ function resample_path(path, N, spacing, closed=false) =
     length = path_length(path,closed),
     N = is_def(N) ? N : round(length/spacing) + (closed?0:1), 
         spacing = length/(closed?N:N-1),     // Note: worried about round-off error, so don't include 
-        distlist = list_range(closed?N:N-1,step=spacing),  // last point when closed=false
+        distlist = range(closed?N:N-1,step=spacing),  // last point when closed=false
     cuts = path_cut_points(path, distlist, closed=closed)
    )
-   concat(subindex(cuts,0),closed?[]:[select(path,-1)]);  // Then add last point here
+   concat(subindex(cuts,0),closed?[]:[last(path)]);  // Then add last point here
 
 
 
diff --git a/quaternions.scad b/quaternions.scad
index eaf9e16..1dc7192 100644
--- a/quaternions.scad
+++ b/quaternions.scad
@@ -223,7 +223,7 @@ function Q_Cumulative(v, _i=0, _acc=[]) =
         v, _i+1,
         concat(
             _acc,
-            [_i==0 ? v[_i] : Q_Mul(v[_i], select(_acc,-1))]
+            [_i==0 ? v[_i] : Q_Mul(v[_i], last(_acc))]
         )
     );
 
diff --git a/regions.scad b/regions.scad
index 8b5ca6b..b76785c 100644
--- a/regions.scad
+++ b/regions.scad
@@ -758,7 +758,7 @@ function offset(
         // Note if !closed the last corner doesn't matter, so exclude it
         parallelcheck =
             (len(sharpcorners)==2 && !closed) ||
-            all_defined(select(sharpcorners,closed?0:1,-1))
+            all_defined(closed? sharpcorners : list_tail(sharpcorners))
     )
     assert(parallelcheck, "Path contains sequential parallel segments (either 180 deg turn or 0 deg turn")
     let(
diff --git a/rounding.scad b/rounding.scad
index cf95e7b..315986a 100644
--- a/rounding.scad
+++ b/rounding.scad
@@ -194,7 +194,7 @@ include <structs.scad>
 //   square = [[0,0],[1,0],[1,1],[0,1]];
 //   spiral = flatten(repeat(concat(square,reverse(square)),5));  // Squares repeat 10 times, forward and backward
 //   squareind = [for(i=[0:9]) each [i,i,i,i]];                   // Index of the square for each point
-//   z = list_range(40)*.2+squareind;
+//   z = range(40)*.2+squareind;
 //   path3d = hstack(spiral,z);                                   // 3D spiral
 //   rounding = squareind/20;
 //       // Setting k=1 means curvature won't be continuous, but curves are as round as possible
@@ -423,13 +423,12 @@ function _rounding_offsets(edgespec,z_dir=1) =
                         ) :
                         edgetype == "circle"? radius==0? [] : [for(i=[1:N]) [radius*(cos(i*90/N)-1), z_dir*abs(radius)*sin(i*90/N)]] :
                         /* smooth */ joint==0 ? [] :
-                        select(
-                                _bezcorner([[0,0],[0,z_dir*abs(joint)],[-joint,z_dir*abs(joint)]], k, $fn=N+2),
-                                1, -1
+                        list_tail(
+                                _bezcorner([[0,0],[0,z_dir*abs(joint)],[-joint,z_dir*abs(joint)]], k, $fn=N+2)
                         )
         )
   
-        quant(extra > 0? concat(offsets, [select(offsets,-1)+[0,z_dir*extra]]) : offsets, 1/1024);
+        quant(extra > 0? concat(offsets, [last(offsets)+[0,z_dir*extra]]) : offsets, 1/1024);
 
 
 
@@ -670,7 +669,7 @@ function _path_join(paths,joint,k=0.5,i=0,result=[],relocate=true,closed=false)
       new_result = [each select(result,loop?nextcut[1]:0,len(revresult)-1-firstcut[1]),
                     each bezpath,
                     nextcut[0],
-                    if (!loop) each select(nextpath,nextcut[1],-1)
+                    if (!loop) each list_tail(nextpath,nextcut[1])
                    ]
   )
   i==len(paths)-(closed?1:2)
@@ -900,7 +899,7 @@ function _make_offset_polyhedron(path,offsets, offset_type, flip_faces, quality,
                                  vertexcount=0, vertices=[], faces=[] )=
         offsetind==len(offsets)? (
                 let(
-                        bottom = list_range(n=len(path),s=vertexcount),
+                        bottom = range(n=len(path),s=vertexcount),
                         oriented_bottom = !flip_faces? bottom : reverse(bottom)
                 ) [vertices, concat(faces,[oriented_bottom])]
         ) : (
@@ -980,8 +979,8 @@ function offset_sweep(
                 : 0,
 
         // "Extra" height enlarges the result beyond the requested height, so subtract it
-        bottom_height = len(offsets_bot)==0 ? 0 : abs(select(offsets_bot,-1)[1]) - struct_val(bottom,"extra"),
-        top_height = len(offsets_top)==0 ? 0 : abs(select(offsets_top,-1)[1]) - struct_val(top,"extra"),
+        bottom_height = len(offsets_bot)==0 ? 0 : abs(last(offsets_bot)[1]) - struct_val(bottom,"extra"),
+        top_height = len(offsets_top)==0 ? 0 : abs(last(offsets_top)[1]) - struct_val(top,"extra"),
 
         height = one_defined([l,h,height], "l,h,height", dflt=u_add(bottom_height,top_height)),
         middle = height-bottom_height-top_height
@@ -1129,7 +1128,7 @@ function os_mask(mask, out=false, extra,check_valid, quality, offset_maxstep, of
   let(
       points = ([for(pt=polygon_shift(mask,origin_index[0])) [xfactor*max(pt.x,0),-max(pt.y,0)]])
   )
-  os_profile(deduplicate(move(-points[1],p=select(points,1,-1))), extra,check_valid,quality,offset_maxstep,offset);
+  os_profile(deduplicate(move(-points[1],p=list_tail(points))), extra,check_valid,quality,offset_maxstep,offset);
 
 
 // Module: convex_offset_extrude()
@@ -1248,8 +1247,8 @@ module convex_offset_extrude(
         offsets_top = _rounding_offsets(top, 1);
 
         // "Extra" height enlarges the result beyond the requested height, so subtract it
-        bottom_height = len(offsets_bot)==0 ? 0 : abs(select(offsets_bot,-1)[1]) - struct_val(bottom,"extra");
-        top_height = len(offsets_top)==0 ? 0 : abs(select(offsets_top,-1)[1]) - struct_val(top,"extra");
+        bottom_height = len(offsets_bot)==0 ? 0 : abs(last(offsets_bot)[1]) - struct_val(bottom,"extra");
+        top_height = len(offsets_top)==0 ? 0 : abs(last(offsets_top)[1]) - struct_val(top,"extra");
 
         height = one_defined([l,h,height], "l,h,height", dflt=u_add(bottom_height,top_height));
         assert(height>=0, "Height must be nonnegative");
@@ -1583,11 +1582,11 @@ function _stroke_end(width,left, right, spec) =
                         cutright = cut[1],
                         // Create updated paths taking into account clipping for end rotation
                         newright = intright?
-                                concat([pathclip[0]],select(right,pathclip[1],-1)) :
-                                concat([pathextend],select(right,1,-1)),
+                                concat([pathclip[0]],list_tail(right,pathclip[1])) :
+                                concat([pathextend],list_tail(right)),
                         newleft = !intright?
-                                concat([pathclip[0]],select(left,pathclip[1],-1)) :
-                                concat([pathextend],select(left,1,-1)),
+                                concat([pathclip[0]],list_tail(left,pathclip[1])) :
+                                concat([pathextend],list_tail(left)),
                         // calculate corner angles, which are different when the cut is negative (outside corner)
                         leftangle = cutleft>=0?
                                 vector_angle([newleft[1],newleft[0],newright[0]])/2 :
@@ -1953,11 +1952,11 @@ function rounded_prism(bottom, top, joint_bot=0, joint_top=0, joint_sides=0, k_b
 function bezier_patch_degenerate(patch, splinesteps=16, reverse=false) =
     assert(is_num(splinesteps), "splinesteps must be a number")
     let(
-        top_degen = patch[0][0] == select(patch[0],-1),
-        bot_degen = select(patch,-1)[0] == select(select(patch,-1),-1),
-        left_degen = patch[0][0] == select(patch,-1)[0],
-        right_degen = select(patch[0],-1) == select(select(patch,-1),-1),
-        samplepts = list_range(splinesteps+1)/splinesteps
+        top_degen = patch[0][0] == last(patch[0]),
+        bot_degen = last(patch)[0] == last(last(patch)),
+        left_degen = patch[0][0] == last(patch)[0],
+        right_degen = last(patch[0]) == last(last(patch)),
+        samplepts = range(splinesteps+1)/splinesteps
     )
     top_degen && bot_degen && left_degen && right_degen ?   // fully degenerate case
         [repeat([patch[0][0]],4), EMPTY_VNF] :
@@ -1965,19 +1964,19 @@ function bezier_patch_degenerate(patch, splinesteps=16, reverse=false) =
         let(  
             pts = bezier_points(subindex(patch,0), samplepts)
         )
-        [[pts,pts,[pts[0]],[select(pts,-1)]], EMPTY_VNF] :
+        [[pts,pts,[pts[0]],[last(pts)]], EMPTY_VNF] :
     left_degen && right_degen ?                             // double degenerate case (sides)
        let(
           pts = bezier_points(patch[0], samplepts)
        )
-       [[[pts[0]], [select(pts,-1)], pts, pts], EMPTY_VNF] :
+       [[[pts[0]], [last(pts)], pts, pts], EMPTY_VNF] :
     !top_degen && !bot_degen ?                             // non-degenerate case
        let(
            k=echo("non-degenerate case"),
            pts = bezier_patch_points(patch, samplepts, samplepts)
        )
        [
-        [subindex(pts,0), subindex(pts,len(pts)-1), pts[0], select(pts,-1)],
+        [subindex(pts,0), subindex(pts,len(pts)-1), pts[0], last(pts)],
         vnf_vertex_array(pts, reverse=reverse)
        ] :
     bot_degen ?                                           // only bottom is degenerate
@@ -1990,22 +1989,22 @@ function bezier_patch_degenerate(patch, splinesteps=16, reverse=false) =
        ] :
     // at this point top_degen is true                   // only top is degenerate
        let(
-           full_degen = patch[1][0] == select(patch[1],-1),
-           rowmax = full_degen ? list_range(splinesteps+1) :
+           full_degen = patch[1][0] == last(patch[1]),
+           rowmax = full_degen ? range(splinesteps+1) :
                                  [for(j=[0:splinesteps]) j<=splinesteps/2 ? 2*j : splinesteps],
            vbb=echo("single degenerate case"),
            bpatch = [for(i=[0:1:len(patch[0])-1]) bezier_points(subindex(patch,i), samplepts)],
            pts = [
                   [bpatch[0][0]],
-                  for(j=[1:splinesteps]) bezier_points(subindex(bpatch,j), list_range(rowmax[j]+1)/rowmax[j])
+                  for(j=[1:splinesteps]) bezier_points(subindex(bpatch,j), range(rowmax[j]+1)/rowmax[j])
                  ],
            vnf = vnf_tri_array(pts, reverse=reverse)
         ) [
             [
              subindex(pts,0),
-             [for(row=pts) select(row,-1)],
+             [for(row=pts) last(row)],
              pts[0],
-             select(pts,-1),
+             last(pts),
             ],
             vnf
           ];
diff --git a/screws.scad b/screws.scad
index 27c6c5c..1ce6ec0 100644
--- a/screws.scad
+++ b/screws.scad
@@ -1085,7 +1085,7 @@ function _ISO_thread_tolerance(diameter, pitch, internal=false, tolerance=undef)
            ],
 
     rangepts = [0.99, 1.4, 2.8, 5.6, 11.2, 22.4, 45, 90, 180, 300],
-    d_ind = floor(lookup(diameter,hstack(rangepts,list_range(len(rangepts))))),
+    d_ind = floor(lookup(diameter,hstack(rangepts,range(len(rangepts))))),
     avgd = sqrt(rangepts[d_ind]* rangepts[d_ind+1]),
 
     T_d2_6 = 90*pow(P, 0.4)*pow(avgd,0.1),
diff --git a/shapes.scad b/shapes.scad
index 1a2ed21..c0eba7c 100644
--- a/shapes.scad
+++ b/shapes.scad
@@ -1339,7 +1339,7 @@ module spheroid(r, style="aligned", d, circum=false, anchor=CENTER, spin=0, orie
             path = [
                 let(a = merids[0]) [0, sin(a)],
                 for (a=merids) [cos(a), sin(a)],
-                let(a = select(merids,-1)) [0, sin(a)]
+                let(a = last(merids)) [0, sin(a)]
             ];
             scale(r) rotate(180) rotate_extrude(convexity=2,$fn=sides) polygon(path);
         } else {
@@ -1441,7 +1441,7 @@ function spheroid(r, style="aligned", d, circum=false, anchor=CENTER, spin=0, or
                 1,
             ],
             offs = cumsum(meridians),
-            pc = select(offs,-1)-1,
+            pc = last(offs)-1,
             os = octa_steps * 2
         ) [
             for (i=[0:1:3]) [0, 1+(i+1)%4, 1+i],
diff --git a/shapes2d.scad b/shapes2d.scad
index 34f92ae..5ba5c2a 100644
--- a/shapes2d.scad
+++ b/shapes2d.scad
@@ -209,10 +209,10 @@ module stroke(
     assert(is_undef(endcap_angle2)||is_num(endcap_angle2));
     assert(is_undef(joint_angle)||is_num(joint_angle));
 
-    endcap_shape1 = _shape_path(endcap1, select(width,0), endcap_width1, endcap_length1, endcap_extent1);
-    endcap_shape2 = _shape_path(endcap2, select(width,-1), endcap_width2, endcap_length2, endcap_extent2);
+    endcap_shape1 = _shape_path(endcap1, width[0], endcap_width1, endcap_length1, endcap_extent1);
+    endcap_shape2 = _shape_path(endcap2, last(width), endcap_width2, endcap_length2, endcap_extent2);
 
-    trim1 = select(width,0) * first_defined([
+    trim1 = width[0] * first_defined([
         trim1, trim,
         (endcap1=="arrow")? endcap_length1-0.01 :
         (endcap1=="arrow2")? endcap_length1*3/4 :
@@ -220,7 +220,7 @@ module stroke(
     ]);
     assert(is_num(trim1));
 
-    trim2 = select(width,-1) * first_defined([
+    trim2 = last(width) * first_defined([
         trim2, trim,
         (endcap2=="arrow")? endcap_length2-0.01 :
         (endcap2=="arrow2")? endcap_length2*3/4 :
@@ -244,8 +244,8 @@ module stroke(
             [lerp(width[epos[0]], width[(epos[0]+1)%len(width)], epos[1])]
         );
 
-        start_vec = select(path,0) - select(path,1);
-        end_vec = select(path,-1) - select(path,-2);
+        start_vec = path[0] - path[1];
+        end_vec = last(path) - select(path,-2);
 
         if (len(path[0]) == 2) {
             // Straight segments
@@ -301,7 +301,7 @@ module stroke(
             }
 
             // Endcap2
-            translate(select(path,-1)) {
+            translate(last(path)) {
                 mat = is_undef(endcap_angle2)? rot(from=BACK,to=end_vec) :
                     zrot(endcap_angle2);
                 multmatrix(mat) polygon(endcap_shape2);
@@ -402,9 +402,9 @@ module stroke(
             }
 
             // Endcap2
-            translate(select(path,-1)) {
-                multmatrix(select(rotmats,-1)) {
-                    $fn = select(sides,-1);
+            translate(last(path)) {
+                multmatrix(last(rotmats)) {
+                    $fn = last(sides);
                     if (is_undef(endcap_angle2)) {
                         rotate_extrude(convexity=convexity) {
                             right_half(planar=true) {
@@ -413,7 +413,7 @@ module stroke(
                         }
                     } else {
                         rotate([90,0,endcap_angle2]) {
-                            linear_extrude(height=max(select(widths,-1),0.001), center=true, convexity=convexity) {
+                            linear_extrude(height=max(last(widths),0.001), center=true, convexity=convexity) {
                                 polygon(endcap_shape2);
                             }
                         }
@@ -791,7 +791,7 @@ function _turtle_command(command, parm, parm2, state, index) =
         chvec = !in_list(command,needvec) || is_vector(parm,2),
         chnum = !in_list(command,neednum) || is_num(parm),
         vec_or_num = !in_list(command,needeither) || (is_num(parm) || is_vector(parm,2)),
-        lastpt = select(state[path],-1)
+        lastpt = last(state[path])
     )
     assert(chvec,str("\"",command,"\" requires a vector parameter at index ",index))
     assert(chnum,str("\"",command,"\" requires a numeric parameter at index ",index))
@@ -2339,8 +2339,8 @@ function mask2d_ogee(pattern, excess, anchor=CENTER, spin=0) =
                 0
             )
         ])),
-        tot_x = select(x,-1),
-        tot_y = select(y,-1),
+        tot_x = last(x),
+        tot_y = last(y),
         data = [
             for (i=idx(pattern,step=2)) let(
                 type = pattern[i],
diff --git a/skin.scad b/skin.scad
index e53def9..8275c51 100644
--- a/skin.scad
+++ b/skin.scad
@@ -444,8 +444,8 @@ function skin(profiles, slices, refine=1, method="direct", sampling, caps, close
     // Define this to be 1 if a profile is used on either side by a resampling method, zero otherwise.
     profile_resampled = [for(i=idx(profiles)) 
       1-(
-           i==0 ?  method_type[0] * (closed? select(method_type,-1) : 1) :
-           i==len(profiles)-1 ? select(method_type,-1) * (closed ? select(method_type,-2) : 1) :
+           i==0 ?  method_type[0] * (closed? last(method_type) : 1) :
+           i==len(profiles)-1 ? last(method_type) * (closed ? select(method_type,-2) : 1) :
          method_type[i] * method_type[i-1])],
     parts = search(1,[1,for(i=[0:1:len(profile_resampled)-2]) profile_resampled[i]!=profile_resampled[i+1] ? 1 : 0],0),
     plen = [for(i=idx(parts)) (i== len(parts)-1? len(refined_len) : parts[i+1]) - parts[i]],
@@ -534,8 +534,8 @@ function _skin_core(profiles, caps) =
                         prof1 = profiles[0]
                 ) [[for (i=idx(prof1)) plens[0]-1-i]],
                 secondcap = !caps[1] ? [] : let(
-            prof2 = select(profiles,-1),
-            eoff = sum(select(plens,0,-2))
+            prof2 = last(profiles),
+            eoff = sum(list_head(plens))
         ) [[for (i=idx(prof2)) eoff+i]]
     ) [vertices, concat(sidefaces,firstcap,secondcap)];
 
@@ -812,7 +812,7 @@ function _skin_tangent_match(poly1, poly2) =
         small = swap ? poly2 : poly1,
         curve_offset = centroid(small)-centroid(big),
         cutpts = [for(i=[0:len(small)-1]) _find_one_tangent(big, select(small,i,i+1),curve_offset=curve_offset)],
-        shift = select(cutpts,-1)+1,
+        shift = last(cutpts)+1,
         newbig = polygon_shift(big, shift),
         repeat_counts = [for(i=[0:len(small)-1]) posmod(cutpts[i]-select(cutpts,i-1),len(big))],
         newsmall = repeat_entries(small,repeat_counts)
@@ -894,7 +894,7 @@ function associate_vertices(polygons, split, curpoly=0) =
            str("Split ",cursplit," at polygon ",curpoly," has invalid vertices.  Must be in [0:",polylen-1,"]"))
     len(cursplit)==0 ? associate_vertices(polygons,split,curpoly+1) :
     let(
-      splitindex = sort(concat(list_range(polylen), cursplit)),
+      splitindex = sort(concat(range(polylen), cursplit)),
       newpoly = [for(i=[0:len(polygons)-1]) i<=curpoly ? select(polygons[i],splitindex) : polygons[i]]
     )
    associate_vertices(newpoly, split, curpoly+1);
@@ -970,10 +970,10 @@ function sweep(shape, transforms, closed=false, caps) =
         rtrans = reverse(transforms),
         vnfs = [
             for (rgn=regions) each [
-                for (path=select(rgn,0,-1))
+                for (path=rgn)
                     sweep(path, transforms, closed=closed, caps=false),
                 if (fullcaps[0]) region_faces(rgn, transform=transforms[0], reverse=true),
-                if (fullcaps[1]) region_faces(rgn, transform=select(transforms,-1)),
+                if (fullcaps[1]) region_faces(rgn, transform=last(transforms)),
             ],
         ],
         vnf = vnf_merge(vnfs)
@@ -1311,7 +1311,7 @@ function path_sweep(shape, path, method="incremental", normal, closed=false, twi
   assert(is_integer(symmetry) && symmetry>0, "symmetry must be a positive integer")
 //  let(shape = check_and_fix_path(shape,valid_dim=2,closed=true,name="shape"))
   assert(is_path(path), "input path is not a path")
-  assert(!closed || !approx(path[0],select(path,-1)), "Closed path includes start point at the end")
+  assert(!closed || !approx(path[0],last(path)), "Closed path includes start point at the end")
   let(
     path = path3d(path),
     caps = is_def(caps) ? caps :
@@ -1350,13 +1350,13 @@ function path_sweep(shape, path, method="incremental", normal, closed=false, twi
             // X axis.  Similarly, in the closed==false case the desired and actual transformations can only differ in the twist,
             // so we can need to calculate the twist angle so we can apply a correction, which we distribute uniformly over the whole path.
             reference_rot = closed ? rotations[0] :   
-                         is_undef(last_normal) ? select(rotations,-1) : 
+                         is_undef(last_normal) ? last(rotations) : 
                            let(
-                               last_tangent = select(tangents,-1),
+                               last_tangent = last(tangents),
                                lastynormal = last_normal - (last_normal * last_tangent) * last_tangent
                            )
                          affine3d_frame_map(y=lastynormal, z=last_tangent),
-            mismatch = transpose(select(rotations,-1)) * reference_rot, 
+            mismatch = transpose(last(rotations)) * reference_rot, 
             correction_twist = atan2(mismatch[1][0], mismatch[0][0]),
             // Spread out this extra twist over the whole sweep so that it doesn't occur
             // abruptly as an artifact at the last step.  
@@ -1492,7 +1492,7 @@ function _ofs_vmap(ofs,closed=false) =
     )
     [
      for(entry=ofs[1]) _ofs_face_edge(entry,firstlen),
-     if (!closed) _ofs_face_edge(select(ofs[1],-1),firstlen,second=true)
+     if (!closed) _ofs_face_edge(last(ofs[1]),firstlen,second=true)
     ];
 
 
diff --git a/strings.scad b/strings.scad
index be287de..147d558 100644
--- a/strings.scad
+++ b/strings.scad
@@ -335,7 +335,7 @@ function _str_find_last(str,pattern,sindex) =
         (sindex >=0 ? sindex : undef);
 
 function _str_find_all(str,pattern) =
-    pattern == "" ? list_range(len(str)) :
+    pattern == "" ? range(len(str)) :
     [for(i=[0:1:len(str)-len(pattern)]) if (_str_cmp(str,i,pattern)) i];
 
 
diff --git a/tests/test_arrays.scad b/tests/test_arrays.scad
index 5b460e2..679f34c 100644
--- a/tests/test_arrays.scad
+++ b/tests/test_arrays.scad
@@ -29,12 +29,14 @@ test_select();
 
 
 module test_slice() {
-    assert(slice([3,4,5,6,7,8,9], 3, 5) == [6,7]);
-    assert(slice([3,4,5,6,7,8,9], 2, -1) == [5,6,7,8,9]);
-    assert(slice([3,4,5,6,7,8,9], 1, 1) == []);
-    assert(slice([3,4,5,6,7,8,9], 6, -1) == [9]);
-    assert(slice([3,4,5,6,7,8,9], 2, -2) == [5,6,7,8]);
-    assert(slice([], 2, -2) == []);
+    l = [3,4,5,6,7,8,9];
+    assert(slice(l, 5, 6) == [8,9]);
+    assert(slice(l, 5, 8) == [8,9]);
+    assert(slice(l, 5, 2) == []);
+    assert(slice(l, -3, -1) == [7,8,9]);
+    assert(slice(l, 3, 3) == [6]);
+    assert(slice(l, 4) == [7,8,9]);
+    assert(slice(l, -2) == [8,9]);
 }
 test_slice();
 
@@ -131,19 +133,36 @@ module test_repeat() {
 test_repeat();
 
 
-module test_list_range() {
-    assert(list_range(4) == [0,1,2,3]);
-    assert(list_range(n=4, step=2) == [0,2,4,6]);
-    assert(list_range(n=4, s=3, step=3) == [3,6,9,12]);
-    assert(list_range(e=3) == [0,1,2,3]);
-    assert(list_range(e=6, step=2) == [0,2,4,6]);
-    assert(list_range(s=3, e=5) == [3,4,5]);
-    assert(list_range(s=3, e=8, step=2) == [3,5,7]);
-    assert(list_range(s=4, e=8, step=2) == [4,6,8]);
-    assert(list_range(e=4, n=3) == [0,2,4]);
-    assert(list_range(n=4, s=[3,4], step=[2,3]) == [[3,4], [5,7], [7,10], [9,13]]);
+module test_range() {
+    assert(range(4) == [0,1,2,3]);
+    assert(range(n=4, step=2) == [0,2,4,6]);
+    assert(range(n=4, s=3, step=3) == [3,6,9,12]);
+    assert(range(e=3) == [0,1,2,3]);
+    assert(range(e=6, step=2) == [0,2,4,6]);
+    assert(range(s=3, e=5) == [3,4,5]);
+    assert(range(s=3, e=8, step=2) == [3,5,7]);
+    assert(range(s=4, e=8, step=2) == [4,6,8]);
+    assert(range(e=4, n=3) == [0,2,4]);
+    assert(range(n=4, s=[3,4], step=[2,3]) == [[3,4], [5,7], [7,10], [9,13]]);
 }
-test_list_range();
+test_range();
+
+
+module test_rangex() {
+    assert_equal(rangex(4), [0,1,2,3]);
+    assert_approx(rangex(5,e=1), [0, 0.2, 0.4, 0.6, 0.8]);
+    assert_equal(rangex(n=4, step=2), [0,2,4,6]);
+    assert_approx(rangex(n=4, step=0.25), [0,0.25,0.5,0.75]);
+    assert_equal(rangex(n=4, s=3, step=3), [3,6,9,12]);
+    assert_equal(rangex(e=3), [0,1,2]);
+    assert_equal(rangex(e=6, step=2), [0,2,4]);
+    assert_equal(rangex(s=3, e=5), [3,4]);
+    assert_equal(rangex(s=3, e=8, step=2), [3,5,7]);
+    assert_equal(rangex(s=4, e=8, step=2), [4,6]);
+    assert_equal(rangex(e=6, n=3), [0,2,4]);
+    assert_equal(rangex(n=4, s=[3,4], step=[2,3]), [[3,4], [5,7], [7,10], [9,13]]);
+}
+test_rangex();
 
 
 module test_reverse() {
@@ -303,7 +322,7 @@ test_enumerate();
 
 
 module test_shuffle() {
-    nums1 = [for (i=list_range(100)) i];
+    nums1 = [for (i=range(100)) i];
     nums2 = shuffle(nums1,33);
     nums3 = shuffle(nums2,99);
     assert(sort(nums2)==nums1);
diff --git a/tests/test_geometry.scad b/tests/test_geometry.scad
index 817323d..5eb4b68 100644
--- a/tests/test_geometry.scad
+++ b/tests/test_geometry.scad
@@ -481,7 +481,7 @@ module test_circle_3points() {
     radii = rands(10,100,count,seed_value=390);
     angles = rands(0,360,count,seed_value=699);
     // 2D tests.
-    for(i = list_range(count)) {
+    for(i = range(count)) {
         cp = select(coords,i,i+1);
         r = radii[i];
         angs = sort(select(angles,i,i+2));
@@ -506,7 +506,7 @@ module test_circle_3points() {
             assert(approx(res[2], UP));
         }
     }
-    for(i = list_range(count)) {
+    for(i = range(count)) {
         cp = select(coords,i,i+1);
         r = radii[i];
         angs = sort(select(angles,i,i+2));
@@ -532,7 +532,7 @@ module test_circle_3points() {
         }
     }
     // 3D tests.
-    for(i = list_range(count)) {
+    for(i = range(count)) {
         cp = select(coords,i,i+2);
         r = radii[i];
         nrm = unit(select(coords,i+10,i+12));
@@ -559,7 +559,7 @@ module test_circle_3points() {
             assert(approx(res[2], n));
         }
     }
-    for(i = list_range(count)) {
+    for(i = range(count)) {
         cp = select(coords,i,i+2);
         r = radii[i];
         nrm = unit(select(coords,i+10,i+12));
@@ -984,8 +984,8 @@ module test_pointlist_bounds() {
 
 
 module test_closest_point() {
-    ptlist = [for (i=list_range(100)) rands(-100,100,2,seed_value=8463)];
-    testpts = [for (i=list_range(100)) rands(-100,100,2,seed_value=6834)];
+    ptlist = [for (i=range(100)) rands(-100,100,2,seed_value=8463)];
+    testpts = [for (i=range(100)) rands(-100,100,2,seed_value=6834)];
     for (pt = testpts) {
         pidx = closest_point(pt,ptlist);
         dists = [for (p=ptlist) norm(pt-p)];
@@ -997,8 +997,8 @@ module test_closest_point() {
 
 
 module test_furthest_point() {
-    ptlist = [for (i=list_range(100)) rands(-100,100,2,seed_value=8463)];
-    testpts = [for (i=list_range(100)) rands(-100,100,2,seed_value=6834)];
+    ptlist = [for (i=range(100)) rands(-100,100,2,seed_value=8463)];
+    testpts = [for (i=range(100)) rands(-100,100,2,seed_value=6834)];
     for (pt = testpts) {
         pidx = furthest_point(pt,ptlist);
         dists = [for (p=ptlist) norm(pt-p)];
diff --git a/tests/test_math.scad b/tests/test_math.scad
index 103be26..e943756 100644
--- a/tests/test_math.scad
+++ b/tests/test_math.scad
@@ -1122,7 +1122,7 @@ module test_real_roots(){
    // Wilkinson polynomial is a nasty test:
    assert_approx(
        sort(real_roots(poly_mult([[1,-1],[1,-2],[1,-3],[1,-4],[1,-5],[1,-6],[1,-7],[1,-8],[1,-9],[1,-10]]))),
-       list_range(n=10,s=1));
+       range(n=10,s=1));
    assert_equal(real_roots([3]), []);
    assert_equal(real_roots(poly_mult([[1,-2,5],[12,-24,24],[-2, -12, -20],[1,-10,50]])),[]);
    assert_equal(real_roots(poly_mult([[1,-2,5],[12,-24,24],[-2, -12, -20],[1,-10,50],[1,0,0]])),[0,0]);
diff --git a/threading.scad b/threading.scad
index ff5ee96..50e1336 100644
--- a/threading.scad
+++ b/threading.scad
@@ -228,13 +228,13 @@ module trapezoidal_threaded_rod(
             zrot(i*360/starts, p=vnf_vertex_array(thread_verts, reverse=left_handed)),
         for (i=[0:1:starts-1]) let(
             rmat = zrot(i*360/starts),
-            pts = deduplicate(select(thread_verts[0], 0, len(prof3d)+1)),
+            pts = deduplicate(list_head(thread_verts[0], len(prof3d)+1)),
             faces = [for (i=idx(pts,e=-2)) [0, i+1, i]],
             rfaces = left_handed? [for (x=faces) reverse(x)] : faces
         ) [apply(rmat,pts), rfaces],
         for (i=[0:1:starts-1]) let(
             rmat = zrot(i*360/starts),
-            pts = deduplicate(select(last(thread_verts), -len(prof3d)-2, -1)),
+            pts = deduplicate(list_tail(last(thread_verts), -len(prof3d)-2)),
             faces = [for (i=idx(pts,e=-2)) [len(pts)-1, i, i+1]],
             rfaces = left_handed? [for (x=faces) reverse(x)] : faces
         ) [apply(rmat,pts), rfaces]
diff --git a/turtle3d.scad b/turtle3d.scad
index c0631d0..7f1e4c5 100644
--- a/turtle3d.scad
+++ b/turtle3d.scad
@@ -479,7 +479,7 @@ function _tupdate(state, tran, pretran) =
     [
      concat(state[0],tran),
      concat(state[1],pretran),
-     each select(state,2,-1)
+     each list_tail(state,2)
     ];
 
 function _turtle3d_command(command, parm, parm2, state, index) =
@@ -504,8 +504,8 @@ function _turtle3d_command(command, parm, parm2, state, index) =
         chnum = (!in_list(command,neednum) || is_num(parm))
                 && (!in_list(command,numornothing) || (is_undef(parm) || is_num(parm))),
         chtran = !in_list(command,needtran) || is_matrix(parm,4,4),
-        lastT = select(state[trlist],-1),
-        lastPre = select(state[prelist],-1),
+        lastT = last(state[trlist]),
+        lastPre = last(state[prelist]),
         lastpt = apply(lastT,[0,0,0])
     )
     assert(chvec,str("\"",command,"\" requires a 3d vector parameter at index ",index))
diff --git a/vnf.scad b/vnf.scad
index 707f1c4..7635cf5 100644
--- a/vnf.scad
+++ b/vnf.scad
@@ -316,7 +316,7 @@ function vnf_vertex_array(
             )
         ]
     )
-    rows<=1 || cols<=1 ? vnf : 
+    rows<=1 || cols<=1 ? vnf :
     vnf_merge(cleanup=true, [
         vnf, [
             verts,
@@ -396,7 +396,7 @@ module vnf_polyhedron(vnf, convexity=2, extent=true, cp=[0,0,0], anchor="origin"
 // Usage:
 //   vnf_wireframe(vnf, <r|d>);
 // Description:
-//   Given a VNF, creates a wire frame ball-and-stick model of the polyhedron with a cylinder for each edge and a sphere at each vertex. 
+//   Given a VNF, creates a wire frame ball-and-stick model of the polyhedron with a cylinder for each edge and a sphere at each vertex.
 // Arguments:
 //   vnf = A vnf structure
 //   r|d = radius or diameter of the cylinders forming the wire frame.  Default: r=1
@@ -404,12 +404,12 @@ module vnf_polyhedron(vnf, convexity=2, extent=true, cp=[0,0,0], anchor="origin"
 //   $fn=32;
 //   ball = sphere(r=20, $fn=6);
 //   vnf_wireframe(ball,d=1);
-// Example: 
+// Example:
 //  include<BOSL2/polyhedra.scad>
 //  $fn=32;
 //  cube_oct = regular_polyhedron_info("vnf", name="cuboctahedron", or=20);
 //  vnf_wireframe(cube_oct);
-// Example: The spheres at the vertex are imperfect at aligning with the cylinders, so especially at low $fn things look prety ugly.  This is normal.  
+// Example: The spheres at the vertex are imperfect at aligning with the cylinders, so especially at low $fn things look prety ugly.  This is normal.
 //  include<BOSL2/polyhedra.scad>
 //  $fn=8;
 //  octahedron = regular_polyhedron_info("vnf", name="octahedron", or=20);
@@ -423,7 +423,7 @@ module vnf_wireframe(vnf, r, d)
                  ]);
   for (e=edges) extrude_from_to(vertex[e[0]],vertex[e[1]]) circle(r=r);
   move_copies(vertex) sphere(r=r);
-}  
+}
 
 
 // Function: vnf_volume()
@@ -451,7 +451,7 @@ function vnf_volume(vnf) =
 //   no holes; otherwise the results are undefined.
 
 // Divide the solid up into tetrahedra with the origin as one vertex.  The centroid of a tetrahedron is the average of its vertices.
-// The centroid of the total is the volume weighted average.  
+// The centroid of the total is the volume weighted average.
 function vnf_centroid(vnf) =
     let(
         verts = vnf[0],
@@ -481,7 +481,7 @@ function _triangulate_planar_convex_polygons(polys) =
         tris = [for (poly=polys) if (len(poly)==3) poly],
         bigs = [for (poly=polys) if (len(poly)>3) poly],
         newtris = [for (poly=bigs) select(poly,-2,0)],
-        newbigs = [for (poly=bigs) select(poly,0,-2)],
+        newbigs = [for (poly=bigs) list_head(poly)],
         newtris2 = _triangulate_planar_convex_polygons(newbigs),
         outtris = concat(tris, newtris, newtris2)
     ) outtris;
@@ -626,7 +626,7 @@ function vnf_bend(vnf,r,d,axis="Z") =
 //   bad edges and vertices, overlaid on a transparent gray polyhedron of the VNF.
 //   .
 //   Currently checks for these problems:
-//   Type    | Color    | Code         | Message 
+//   Type    | Color    | Code         | Message
 //   ------- | -------- | ------------ | ---------------------------------
 //   WARNING | Yellow   | BIG_FACE     | Face has more than 3 vertices, and may confuse CGAL.
 //   WARNING | Brown    | NULL_FACE    | Face has zero area.
@@ -695,7 +695,7 @@ function vnf_bend(vnf,r,d,axis="Z") =
 //       move([75,35,30],p=vnf_triangulate(linear_sweep(square(100,center=true), height=100)))
 //   ]);
 //   vnf_validate(vnf,size=2,check_isects=true);
-// Example: HOLE_EDGE Errors; Edges Adjacent to Holes.  
+// Example: HOLE_EDGE Errors; Edges Adjacent to Holes.
 //   vnf = skin([
 //       path3d(regular_ngon(n=4, d=100),0),
 //       path3d(regular_ngon(n=5, d=100),100)

From 257f1ec1f8144bb4cb5b2241fc88e5c8d8dc3092 Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 30 Mar 2021 15:27:57 -0700
Subject: [PATCH 02/18] Setup Problem Matcher.  Added some deliberate docs
 errors to test with.

---
 .github/openscad_docsgen.json | 21 +++++++++++++++++++++
 .github/workflows/main.yml    |  1 +
 .gitignore                    |  1 +
 math.scad                     |  9 +++++++--
 4 files changed, 30 insertions(+), 2 deletions(-)
 create mode 100644 .github/openscad_docsgen.json

diff --git a/.github/openscad_docsgen.json b/.github/openscad_docsgen.json
new file mode 100644
index 0000000..813bec6
--- /dev/null
+++ b/.github/openscad_docsgen.json
@@ -0,0 +1,21 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "openscad_docsgen",
+            "pattern": [
+                {
+                    "regexp": "^!! (WARNING|ERROR) at ([^:]+):(\\d+): (.*)$",
+                    "severity": 1,
+                    "file": 2,
+                    "line": 3,
+                    "message": 4
+                },
+                {
+                    "regexp": "^     (.*)$",
+                    "message": 1,
+                    "loop": true
+                }
+            ]
+        }
+    ]
+}
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 88f0279..69eed65 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -56,6 +56,7 @@ jobs:
     - name: Generating Docs
       run: |
         cd $GITHUB_WORKSPACE
+        echo "::add-matcher::.github/openscad_docsgen.json"
         export OPENSCADPATH=$(dirname $GITHUB_WORKSPACE)
         openscad-docsgen -Tm *.scad
 
diff --git a/.gitignore b/.gitignore
index c1a80aa..8289a30 100644
--- a/.gitignore
+++ b/.gitignore
@@ -109,4 +109,5 @@ ENV/
 foo.scad
 BOSL2.wiki
 /ref/
+docsgen_report.json
 
diff --git a/math.scad b/math.scad
index 2297a29..10e8544 100644
--- a/math.scad
+++ b/math.scad
@@ -33,7 +33,7 @@ NAN = acos(2);
 //   sqr(x);
 // Description:
 //   If given a number, returns the square of that number,
-//   If given a vector, returns the sum-of-squares/dot product of the vector elements.
+//   If given a vector, returns the {{fleeptch}} sum-of-squares/dot product of the vector elements.
 //   If given a matrix, returns the matrix multiplication of the matrix with itself.
 // Examples:
 //   sqr(3);     // Returns: 9
@@ -63,8 +63,9 @@ function log2(x) =
 // Function: hypot()
 // Usage:
 //   l = hypot(x,y,<z>);
+// See Also: cthulhoo()
 // Description:
-//   Calculate hypotenuse length of a 2D or 3D triangle.
+//   Calculate hypotenuse length of {{gurptch}} a 2D or 3D triangle.
 // Arguments:
 //   x = Length on the X axis.
 //   y = Length on the Y axis.
@@ -80,6 +81,8 @@ function hypot(x,y,z=0) =
 // Function: factorial()
 // Usage:
 //   x = factorial(n,<d>);
+// See Also:
+//   tiddeebowl()
 // Description:
 //   Returns the factorial of the given integer value, or n!/d! if d is given.  
 // Arguments:
@@ -106,6 +109,8 @@ function factorial(n,d=0) =
 //   x = binomial(3);  // Returns: [1,3,3,1]
 //   y = binomial(4);  // Returns: [1,4,6,4,1]
 //   z = binomial(6);  // Returns: [1,6,15,20,15,6,1]
+// Example(2D):
+//   fleegul_numan(]);
 function binomial(n) =
     assert( is_int(n) && n>0, "Input is not an integer greater than 0.")
     [for( c = 1, i = 0; 

From 527215fa27a9d85044e52230956c9f57afcc7dca Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 30 Mar 2021 16:10:35 -0700
Subject: [PATCH 03/18] Tweak Problem Matcher.

---
 .github/openscad_docsgen.json | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/.github/openscad_docsgen.json b/.github/openscad_docsgen.json
index 813bec6..3520cfd 100644
--- a/.github/openscad_docsgen.json
+++ b/.github/openscad_docsgen.json
@@ -1,14 +1,13 @@
 {
     "problemMatcher": [
         {
-            "owner": "openscad_docsgen",
+            "owner": "docsgen_script",
             "pattern": [
                 {
-                    "regexp": "^!! (WARNING|ERROR) at ([^:]+):(\\d+): (.*)$",
+                    "regexp": "^!! (WARNING|ERROR) at ([^:]+):(\\d+): Failed OpenSCAD script:$",
                     "severity": 1,
                     "file": 2,
-                    "line": 3,
-                    "message": 4
+                    "line": 3
                 },
                 {
                     "regexp": "^     (.*)$",
@@ -16,6 +15,18 @@
                     "loop": true
                 }
             ]
+        },
+        {
+            "owner": "docsgen",
+            "pattern": [
+                {
+                    "regexp": "^!! (WARNING|ERROR) at ([^:]+):(\\d+): (.*[^:])$",
+                    "severity": 1,
+                    "file": 2,
+                    "line": 3,
+                    "message": 4
+                }
+            ]
         }
     ]
 }

From 1745dbbb7faa71ad2c9ef58e67e75b3be05fbc9f Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 30 Mar 2021 16:13:29 -0700
Subject: [PATCH 04/18] slice() cleanup tweak.

---
 vnf.scad | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vnf.scad b/vnf.scad
index 7635cf5..9c05e0f 100644
--- a/vnf.scad
+++ b/vnf.scad
@@ -481,7 +481,7 @@ function _triangulate_planar_convex_polygons(polys) =
         tris = [for (poly=polys) if (len(poly)==3) poly],
         bigs = [for (poly=polys) if (len(poly)>3) poly],
         newtris = [for (poly=bigs) select(poly,-2,0)],
-        newbigs = [for (poly=bigs) list_head(poly)],
+        newbigs = [for (poly=bigs) select(poly,0,-2)],
         newtris2 = _triangulate_planar_convex_polygons(newbigs),
         outtris = concat(tris, newtris, newtris2)
     ) outtris;

From 23372f2b2ee0b3542ee600b5b53bd28b04060f8e Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 30 Mar 2021 16:44:47 -0700
Subject: [PATCH 05/18] Removed delibrate docs errors.

---
 math.scad | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/math.scad b/math.scad
index 10e8544..2297a29 100644
--- a/math.scad
+++ b/math.scad
@@ -33,7 +33,7 @@ NAN = acos(2);
 //   sqr(x);
 // Description:
 //   If given a number, returns the square of that number,
-//   If given a vector, returns the {{fleeptch}} sum-of-squares/dot product of the vector elements.
+//   If given a vector, returns the sum-of-squares/dot product of the vector elements.
 //   If given a matrix, returns the matrix multiplication of the matrix with itself.
 // Examples:
 //   sqr(3);     // Returns: 9
@@ -63,9 +63,8 @@ function log2(x) =
 // Function: hypot()
 // Usage:
 //   l = hypot(x,y,<z>);
-// See Also: cthulhoo()
 // Description:
-//   Calculate hypotenuse length of {{gurptch}} a 2D or 3D triangle.
+//   Calculate hypotenuse length of a 2D or 3D triangle.
 // Arguments:
 //   x = Length on the X axis.
 //   y = Length on the Y axis.
@@ -81,8 +80,6 @@ function hypot(x,y,z=0) =
 // Function: factorial()
 // Usage:
 //   x = factorial(n,<d>);
-// See Also:
-//   tiddeebowl()
 // Description:
 //   Returns the factorial of the given integer value, or n!/d! if d is given.  
 // Arguments:
@@ -109,8 +106,6 @@ function factorial(n,d=0) =
 //   x = binomial(3);  // Returns: [1,3,3,1]
 //   y = binomial(4);  // Returns: [1,4,6,4,1]
 //   z = binomial(6);  // Returns: [1,6,15,20,15,6,1]
-// Example(2D):
-//   fleegul_numan(]);
 function binomial(n) =
     assert( is_int(n) && n>0, "Input is not an integer greater than 0.")
     [for( c = 1, i = 0; 

From 21a8ec04ec6aefcb33501ace63efa4c014cafa04 Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 30 Mar 2021 16:50:30 -0700
Subject: [PATCH 06/18] Updated docsgen workflow for Problem Matcher

---
 .github/workflows/docsgen.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/docsgen.yml b/.github/workflows/docsgen.yml
index bb854ca..dc46a53 100644
--- a/.github/workflows/docsgen.yml
+++ b/.github/workflows/docsgen.yml
@@ -36,6 +36,7 @@ jobs:
       run: |
         cd $GITHUB_WORKSPACE
         export OPENSCADPATH=$(dirname $GITHUB_WORKSPACE)
+        echo "::add-matcher::.github/openscad_docsgen.json"
         openscad-docsgen -m -i -t -c *.scad
         cd BOSL2.wiki
         git config user.name github-actions

From 36fed2c670628a3cb8d4d404315b90ec58065b46 Mon Sep 17 00:00:00 2001
From: github-actions <github-actions@github.com>
Date: Wed, 31 Mar 2021 01:57:07 +0000
Subject: [PATCH 07/18] Bump release version.

---
 version.scad | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/version.scad b/version.scad
index 14eed9e..d38bcfa 100644
--- a/version.scad
+++ b/version.scad
@@ -6,7 +6,7 @@
 //////////////////////////////////////////////////////////////////////
 
 
-BOSL_VERSION = [2,0,597];
+BOSL_VERSION = [2,0,598];
 
 
 // Section: BOSL Library Version Functions

From dd1396704926332d0d835962e0e57d95113551f5 Mon Sep 17 00:00:00 2001
From: Adrian Mariano <avm4@cornell.edu>
Date: Fri, 2 Apr 2021 16:59:29 -0400
Subject: [PATCH 08/18] Cleanup of path_resample, add tests for round_corners,
 fix bezier_curve and arc to always return n points for either endpoint
 setting.

---
 beziers.scad             |  8 +++++---
 paths.scad               | 36 +++++++++++++++++++++---------------
 rounding.scad            |  2 +-
 shapes2d.scad            |  4 ++--
 tests/test_shapes2d.scad |  2 +-
 5 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/beziers.scad b/beziers.scad
index fb49adc..721d8cf 100644
--- a/beziers.scad
+++ b/beziers.scad
@@ -435,9 +435,11 @@ function bezier_curvature(curve, u) =
 //   bez = [[0,0], [5,15], [40,20], [60,-15], [80,0]];
 //   move_copies(bezier_curve(bez, 8)) sphere(r=1.5, $fn=12);
 //   trace_bezier(bez, N=len(bez)-1);
-function bezier_curve(curve,n,endpoint) = [each bezier_points(curve, [0:1/n:(n-0.5)/n]),
-                                           if (endpoint) curve[len(curve)-1]
-                                          ];
+function bezier_curve(curve,n,endpoint=true) =
+      [
+         each bezier_points(curve, rangex(endpoint?n-1:n,0,1)),
+         if (endpoint) last(curve)
+      ];
 
 // Function: bezier_segment_closest_point()
 // Usage:
diff --git a/paths.scad b/paths.scad
index d5ebae7..e7f765c 100644
--- a/paths.scad
+++ b/paths.scad
@@ -1238,15 +1238,17 @@ module path_extrude(path, convexity=10, clipsize=100) {
 module path_spread(path, n, spacing, sp=undef, rotate_children=true, closed=false)
 {
     length = path_length(path,closed);
-    distances = is_def(sp)? (
-        is_def(n) && is_def(spacing)? range(s=sp, step=spacing, n=n) :
-        is_def(n)? range(s=sp, e=length, n=n) :
-        range(s=sp, step=spacing, e=length)
-    ) : is_def(n) && is_undef(spacing)? (
-        closed?
-            let(range=range(s=0,e=length, n=n+1)) list_head(range) :
-            range(s=0, e=length, n=n)
-    ) : (
+    distances =
+        is_def(sp)? (   // Start point given
+            is_def(n) && is_def(spacing)? range(s=sp, step=spacing, n=n) :
+            is_def(n)? range(s=sp, e=length, n=n) :
+            range(s=sp, step=spacing, e=length)
+        )
+      : is_def(n) && is_undef(spacing)? ( let(a=echo(n=n))  // N alone given
+            closed ? rangex(s=0, e=length, n=n)
+                   : range(s=0, e=length, n=n)
+        )
+      : (      // No start point and spacing is given, N maybe given
         let(
             n = is_def(n)? n : floor(length/spacing)+(closed?0:1),
             ptlist = range(s=0,step=spacing,n=n),
@@ -1600,13 +1602,17 @@ function resample_path(path, N, spacing, closed=false) =
    assert(num_defined([N,spacing])==1,"Must define exactly one of N and spacing")
    assert(is_bool(closed))
    let(
-    length = path_length(path,closed),
-    N = is_def(N) ? N : round(length/spacing) + (closed?0:1), 
-        spacing = length/(closed?N:N-1),     // Note: worried about round-off error, so don't include 
-        distlist = range(closed?N:N-1,step=spacing),  // last point when closed=false
-    cuts = path_cut_points(path, distlist, closed=closed)
+       length = path_length(path,closed),
+       // In the open path case decrease N by 1 so that we don't try to get
+       // path_cut to return the endpoint (which might fail due to rounding)
+       // Add last point later
+       N = is_def(N) ? N-(closed?0:1) : round(length/spacing),
+       distlist = rangex(N,e=length), 
+       cuts = path_cut_points(path, distlist, closed=closed)
    )
-   concat(subindex(cuts,0),closed?[]:[last(path)]);  // Then add last point here
+   [ each subindex(cuts,0),
+     if (!closed) last(path)     // Then add last point here
+   ];
 
 
 
diff --git a/rounding.scad b/rounding.scad
index 315986a..815e220 100644
--- a/rounding.scad
+++ b/rounding.scad
@@ -346,7 +346,7 @@ function _bezcorner(points, parm) =
                         ] : _smooth_bez_fill(points,parm),
                 N = max(3,$fn>0 ?$fn : ceil(bezier_segment_length(P)/$fs))
         )
-        bezier_curve(P,N,endpoint=true);
+        bezier_curve(P,N+1,endpoint=true);
 
 function _chamfcorner(points, parm) =
         let(
diff --git a/shapes2d.scad b/shapes2d.scad
index 5ba5c2a..e14467e 100644
--- a/shapes2d.scad
+++ b/shapes2d.scad
@@ -533,7 +533,7 @@ module dashed_stroke(path, dashpat=[3,3], width=1, closed=false) {
 function arc(N, r, angle, d, cp, points, width, thickness, start, wedge=false, long=false, cw=false, ccw=false, endpoint=true) =
     assert(is_bool(endpoint))
     !endpoint ? assert(!wedge, "endpoint cannot be false if wedge is true")
-               list_head(arc(N,r,angle,d,cp,points,width,thickness,start,wedge,long,cw,ccw,true)) :
+               list_head(arc(N+1,r,angle,d,cp,points,width,thickness,start,wedge,long,cw,ccw,true)) :
     assert(is_undef(N) || is_integer(N), "Number of points must be an integer")
     // First try for 2D arc specified by width and thickness
     is_def(width) && is_def(thickness)? (
@@ -1875,7 +1875,7 @@ function reuleaux_polygon(N=3, r, d, anchor=CENTER, spin=0) =
                 sa = ca + 180 + (90/N),
                 ea = ca + 180 - (90/N),
                 cp = polar_to_xy(r, ca)
-            ) each arc(N=ssegs, r=slen, cp=cp, angle=[sa,ea], endpoint=false)
+            ) each arc(N=ssegs-1, r=slen, cp=cp, angle=[sa,ea], endpoint=false)
         ],
         anchors = [
             for (i = [0:1:N-1]) let(
diff --git a/tests/test_shapes2d.scad b/tests/test_shapes2d.scad
index c13a33d..e31f022 100644
--- a/tests/test_shapes2d.scad
+++ b/tests/test_shapes2d.scad
@@ -40,7 +40,7 @@ test_turtle();
 
 module test_arc() {
     assert_approx(arc(N=8, d=100, angle=135, cp=[10,10]), [[60,10],[57.1941665154,26.5139530978],[49.0915741234,41.1744900929],[36.6016038258,52.3362099614],[21.1260466978,58.7463956091],[4.40177619483,59.6856104947],[-11.6941869559,55.0484433951],[-25.3553390593,45.3553390593]]);
-    assert_approx(arc(N=8, d=100, angle=135, cp=[10,10],endpoint=false), [[60,10],[57.1941665154,26.5139530978],[49.0915741234,41.1744900929],[36.6016038258,52.3362099614],[21.1260466978,58.7463956091],[4.40177619483,59.6856104947],[-11.6941869559,55.0484433951]]);    
+    assert_approx(arc(N=8, d=100, angle=135, cp=[10,10],endpoint=false), [[60,10],[57.8470167866,24.5142338627],[51.5734806151,37.778511651],[41.7196642082,48.6505226681],[29.1341716183,56.1939766256],[14.9008570165,59.7592363336],[0.245483899194,59.0392640202],[-13.5698368413,54.0960632174]]);
     assert_approx(arc(N=8, d=100, angle=[45,225], cp=[10,10]), [[45.3553390593,45.3553390593],[26.5139530978,57.1941665154],[4.40177619483,59.6856104947],[-16.6016038258,52.3362099614],[-32.3362099614,36.6016038258],[-39.6856104947,15.5982238052],[-37.1941665154,-6.51395309776],[-25.3553390593,-25.3553390593]]);
     assert_approx(arc(N=8, d=100, start=45, angle=135, cp=[10,10]), [[45.3553390593,45.3553390593],[31.6941869559,55.0484433951],[15.5982238052,59.6856104947],[-1.12604669782,58.7463956091],[-16.6016038258,52.3362099614],[-29.0915741234,41.1744900929],[-37.1941665154,26.5139530978],[-40,10]]);
     assert_approx(arc(N=8, d=100, start=45, angle=-90, cp=[10,10]), [[45.3553390593,45.3553390593],[52.3362099614,36.6016038258],[57.1941665154,26.5139530978],[59.6856104947,15.5982238052],[59.6856104947,4.40177619483],[57.1941665154,-6.51395309776],[52.3362099614,-16.6016038258],[45.3553390593,-25.3553390593]]);

From 194f4a5b1fccac777e22502cfd8f4385d850b168 Mon Sep 17 00:00:00 2001
From: Adrian Mariano <avm4@cornell.edu>
Date: Fri, 2 Apr 2021 17:00:58 -0400
Subject: [PATCH 09/18] rounding tests

---
 tests/test_rounding.scad | 42 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 tests/test_rounding.scad

diff --git a/tests/test_rounding.scad b/tests/test_rounding.scad
new file mode 100644
index 0000000..c3ebfb0
--- /dev/null
+++ b/tests/test_rounding.scad
@@ -0,0 +1,42 @@
+include <../std.scad>
+include <../rounding.scad>
+
+module test_round_corners() {
+
+    test1 = turtle(["move", 10, "move", 10, "left", 30, "move", 17, "left", 155, "move", 10, "right", 90, "move", 10,"left", 90, "move", 30]);
+    test2 = turtle(["move", 20, "left", 30, "move", 17, "left", 155, "move", 10, "right", 90, "move", 10,"left", 90, "move", 30]);
+
+    assert_approx(round_corners(test2, cut=.5, $fn=8,closed=true),
+    [[-0.606288551887,1.51404651037],[0.280235443937,0.414087063263],[1.63092692777,0],[16.2021229436,0],[19.8705904774,0.482962913145],[23.2890580113,1.89893852818],[34.1829092195,8.18850645576],[34.2505074296,8.28809878531],[34.2143124553,8.40289457772],[34.1018154298,8.44570309758],[25.9629982589,7.73364886061],[25.0818786883,8.01146479408],[24.6552785953,8.83095594797],[23.994133744,16.387876178],[23.5675336511,17.2073673319],[22.6864140805,17.4851832654],[-5.00680751277,15.0623403194],[-5.5709968443,14.7138107731],[-5.62744081644,14.0530562616]]);
+
+    assert_approx(round_corners(test2, cut=.5, $fn=8,closed=false),
+     [[0,0],[16.2021229436,0],[19.8705904774,0.482962913145],[23.2890580113,1.89893852818],[34.1829092195,8.18850645576],[34.2505074296,8.28809878531],[34.2143124553,8.40289457772],[34.1018154298,8.44570309758],[25.9629982589,7.73364886061],[25.0818786883,8.01146479408],[24.6552785953,8.83095594797],[23.994133744,16.387876178],[23.5675336511,17.2073673319],[22.6864140805,17.4851832654],[-5.99691348681,14.975717271]]);
+
+    assert_approx(round_corners(test2, radius=[9,1.5,1.5,3], $fn=8,closed=false),[[0,0],[17.5884572681,0],[19.917828674,0.306667563398],[22.0884572681,1.20577136594],[28.8628496345,5.11696862225],[29.5970120924,6.19860893897],[29.2039100968,7.44536918473],[27.9821160204,7.91029877507],[26.2547769306,7.75917618664],[25.1598619019,8.1044015691],[24.6297512693,9.12273461966],[24.1503946842,14.6018054592],[23.090173419,16.6384715603],[20.9003433617,17.3289223252],[-5.99691348681,14.975717271]]);
+
+    assert_approx(round_corners(test2, radius=[0,9,1.5,1.5,3,0], $fn=8,closed=false),[[0,0],[17.5884572681,0],[19.917828674,0.306667563398],[22.0884572681,1.20577136594],[28.8628496345,5.11696862225],[29.5970120924,6.19860893897],[29.2039100968,7.44536918473],[27.9821160204,7.91029877507],[26.2547769306,7.75917618664],[25.1598619019,8.1044015691],[24.6297512693,9.12273461966],[24.1503946842,14.6018054592],[23.090173419,16.6384715603],[20.9003433617,17.3289223252],[-5.99691348681,14.975717271]]);
+
+    assert_approx(round_corners(test2, radius=[4,9,1.5,1.5,3,5], $fn=8,closed=true), [[-1.00632035384,2.51302092923],[0.46513599873,0.687303493898],[2.70701955022,0],[17.5884572681,0],[19.917828674,0.306667563398],[22.0884572681,1.20577136594],[28.8628496345,5.11696862225],[29.5970120924,6.19860893897],[29.2039100968,7.44536918473],[27.9821160204,7.91029877507],[26.2547769306,7.75917618664],[25.1598619019,8.1044015691],[24.6297512693,9.12273461966],[24.1503946842,14.6018054592],[23.090173419,16.6384715603],[20.9003433617,17.3289223252],[0.712818162855,15.5627427257],[-3.11056954856,13.2008342139],[-3.49307800348,8.72304539674]]);
+
+    assert_approx(round_corners(test1, radius=[4,0,9,1.5,1.5,3,5], $fn=8, closed=true),[[-1.00632035384,2.51302092923],[0.46513599873,0.687303493898],[2.70701955022,0],[10,0],[17.5884572681,0],[19.917828674,0.306667563398],[22.0884572681,1.20577136594],[28.8628496345,5.11696862225],[29.5970120924,6.19860893897],[29.2039100968,7.44536918473],[27.9821160204,7.91029877507],[26.2547769306,7.75917618664],[25.1598619019,8.1044015691],[24.6297512693,9.12273461966],[24.1503946842,14.6018054592],[23.090173419,16.6384715603],[20.9003433617,17.3289223252],[0.712818162855,15.5627427257],[-3.11056954856,13.2008342139],[-3.49307800348,8.72304539674]]);
+
+    assert_approx(round_corners(test1, joint=3, $fn=8, closed=true),[[-1.11523430308,2.78500492805],[0.515477620423,0.76169028093],[3,0],[7,0],[13,0],[17,0],[19.8977774789,0.381499642545],[22.5980762114,1.5],[32.124355653,7],[32.4498754498,7.47958777023],[32.2755782213,8.03238795439],[31.7338477701,8.23853277176],[27.7490689777,7.88990980077],[25.5592389204,8.58036056568],[24.4990176552,10.6170266668],[24.1503946842,14.6018054592],[23.090173419,16.6384715603],[20.9003433617,17.3289223252],[-3.00832939254,15.2371844993],[-4.71130594915,14.1851659419],[-4.88167918373,12.190712343]]);
+
+    assert_approx(round_corners(test1, joint=3, $fn=8, method="chamfer", closed=true), [[-1.11523430308,2.78500492805],[3,0],[7,0],[13,0],[17,0],[22.5980762114,1.5],[32.124355653,7],[31.7338477701,8.23853277176],[27.7490689777,7.88990980077],[24.4990176552,10.6170266668],[24.1503946842,14.6018054592],[20.9003433617,17.3289223252],[-3.00832939254,15.2371844993],[-4.88167918373,12.190712343]]);
+
+    assert_approx(round_corners(test1, joint=3, $fn=4, method="smooth", closed=true),[[-1.11523430308,2.78500492805],[-0.506080589514,1.46865494252],[0.353393568173,0.522188424009],[1.55153656203,0.0761524785012],[3,0],[7,0],[8.5,0],[10,0],[11.5,0],[13,0],[17,0],[18.4890098964,0.041015625],[19.9246392896,0.28125],[21.2880480021,0.791015625],[22.5980762114,1.5],[32.124355653,7],[33.2706335159,7.70183488048],[33.674933057,8.1697248947],[33.0753795745,8.32110126636],[31.7338477701,8.23853277176],[27.7490689777,7.88990980077],[26.3293465324,7.8480447775],[25.2718192958,8.2378271955],[24.7043208711,9.21160321051],[24.4990176552,10.6170266668],[24.1503946842,14.6018054592],[23.9450914683,16.0072289155],[23.3775930436,16.9810049305],[22.320065807,17.3707873485],[20.9003433617,17.3289223252],[-3.00832939254,15.2371844993],[-4.39040765537,15.0374479012],[-5.22744753731,14.5025539523],[-5.32708255097,13.514211823],[-4.88167918373,12.190712343]]);
+
+    assert_approx(round_corners(test1, joint=3, $fn=4, method="smooth", k=.1, closed=true), [[-1.11523430308,2.78500492805],[-0.374134800869,0.998685360916],[0.164916998481,0.243687931204],[1.06619720521,0.0239336361004],[3,0],[7,0],[8.95,0],[10,0],[11.05,0],[13,0],[17,0],[18.9465459674,0.012890625],[19.9648316685,0.13125],[20.9058726414,0.537890625],[22.5980762114,1.5],[32.124355653,7],[33.7650948284,7.95986239101],[34.2335990876,8.34587161753],[33.6284170693,8.39334886112],[31.7338477701,8.23853277176],[27.7490689777,7.88990980077],[25.829925477,7.74788623096],[24.9991076092,7.91282206324],[24.6924075141,8.70237713407],[24.4990176552,10.6170266668],[24.1503946842,14.6018054592],[23.9570048253,16.5164549919],[23.6503047302,17.3060100627],[22.8194868624,17.470945895],[20.9003433617,17.3289223252],[-3.00832939254,15.2371844993],[-4.91564186446,15.0455441488],[-5.63782937704,14.7549077223],[-5.57131429138,13.9792788941],[-4.88167918373,12.190712343]]);
+
+    assert_approx(round_corners(test1, joint=[3,0,3,5,2,2,4], $fn=4, method="smooth", k=[.8,0,.7,.5,0,.4,1], closed=true),[[-1.11523430308,2.78500492805],[-0.605039930997,1.82113212873],[0.494750995442,0.731063793612],[1.91554107964,0.115316610302],[3,0],[10,0],[17,0],[18.2602418609,0.055078125],[19.9045431002,0.35625],[21.4791356824,0.917578125],[22.5980762114,1.5],[30.3923048454,6],[32.3027679503,7.1697248008],[32.9766005188,7.94954149117],[31.9773447146,8.20183544393],[29.7414583739,8.06422128626],[26.7528742796,7.80275405802],[25.3902084366,7.69137858706],[24.8741147528,7.76386137763],[24.713114411,8.25952793415],[24.5861733979,9.62083196871],[24.0632389414,15.5980001573],[23.9283556903,16.6198201409],[23.5934897955,17.2383006602],[22.9262565325,17.4606811745],[21.8965380598,17.4160780679],[-2.01213469444,15.324340242],[-2.97951536307,15.0445310318],[-4.28698915458,13.9242432294],[-4.69675267167,12.2519315552],[-4.50993441604,11.262377367]]);
+
+    assert_approx(round_corners(test2, cut=.6, $fn=4, method="smooth", k=[.8,.7,.5,0,.4,1], closed=true), [[-0.758025389489,1.89296943206],[-0.411245984888,1.23782454268],[0.336282532724,0.496904475915],[1.30199436026,0.0783807655462],[2.03910170463,0],[15.1195326672,0],[17.1697224117,0.0896023299387],[19.8447085729,0.579555495773],[22.4062911263,1.49273668813],[24.2266086926,2.44023366641],[33.3031485364,7.68057638855],[33.9293399672,8.06397643682],[34.1502016939,8.3195765203],[33.8226761739,8.40227076906],[33.0898209499,8.35716505304],[31.5228787369,8.220075373],[26.897837498,7.84205448929],[25.1461574492,8.08806923839],[24.5997041686,9.77041731835],[24.1688520829,14.390836426],[24.116478533,14.9894688406],[23.9403981733,16.3233811597],[23.5032548901,17.1307628876],[22.6322299704,17.4210646163],[21.2880067431,17.3628384763],[-4.80585474409,15.0799214086],[-5.0950068559,14.9962858485],[-5.48581351579,14.6614294736],[-5.6082926909,14.161572005],[-5.55245232227,13.8657921816]]);
+
+    assert_approx(round_corners([[0,0],[10,0],[10,10]], cut=1, method="chamfer",closed=false), [[0,0],[8.58578643763,0],[10,1.41421356237],[10,10]]);
+
+}
+test_round_corners();
+
+
+
+// vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap

From 957907200b7e4eaea8353cd0a7b4a3db1a28ff6e Mon Sep 17 00:00:00 2001
From: Adrian Mariano <avm4@cornell.edu>
Date: Fri, 2 Apr 2021 20:39:14 -0400
Subject: [PATCH 10/18] bezier doc fixes, test for complex()

---
 beziers.scad         | 15 ++++++++-------
 tests/test_math.scad |  9 +++++++++
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/beziers.scad b/beziers.scad
index 721d8cf..79ecac8 100644
--- a/beziers.scad
+++ b/beziers.scad
@@ -413,16 +413,17 @@ function bezier_curvature(curve, u) =
 // Topics: Bezier Segments
 // See Also: bezier_curvature(), bezier_tangent(), bezier_derivative(), bezier_points()
 // Description:
-//   Takes a list of bezier curve control points and generates n points along the bezier path.  
-//   Points start at the first control point and are sampled every `1/n`th
-//   of the way along the bezier parameter, ending *before* the final control point by default.
-//   The distance between the points will *not* be equidistant.  If you wish to add the
-//   endpoint you can set `endpoint` to true.  The degree of the bezier curve is one
-//   less than the number of points in `curve`.
+//   Takes a list of bezier control points and generates n points along the bezier curve they define.
+//   Points start at the first control point and are sampled uniformly along the bezier parameter.
+//   The endpoints of the output will be *exactly* equal to the first and last bezier control points
+//   when endpoint is true.  If endpoint is false the sampling stops one step before the final point
+//   of the bezier curve, but you still get n, more tightly spaced, points.  
+//   The distance between the points will *not* be equidistant.  
+//   The degree of the bezier curve is one less than the number of points in `curve`.
 // Arguments:
 //   curve = The list of endpoints and control points for this bezier segment.
 //   n = The number of points to generate along the bezier curve.
-//   endpoint = if true then add the endpoint (an extra point, giving n+1 points output).  Default: False
+//   endpoint = if false then exclude the endpoint.  Default: True
 // Example(2D): Quadratic (Degree 2) Bezier.
 //   bez = [[0,0], [30,30], [80,0]];
 //   move_copies(bezier_curve(bez, 8)) sphere(r=1.5, $fn=12);
diff --git a/tests/test_math.scad b/tests/test_math.scad
index e943756..35098a1 100644
--- a/tests/test_math.scad
+++ b/tests/test_math.scad
@@ -830,6 +830,15 @@ module test_lcm() {
 test_lcm();
 
 
+
+module test_complex(){
+    assert_equal( complex(ident(4)), c_ident(4));
+    assert_equal( complex(3), [3,0]);
+    assert_equal( complex([1,2]), [[1,0],[2,0]]);
+    assert_equal( complex([[1,2],[3,4]]), [[ [1,0],[2,0] ], [ [3,0],[4,0]]]);
+}
+test_complex();
+
 module test_c_mul() {
     assert_equal(c_mul([4,5],[9,-4]), [56,29]);
     assert_equal(c_mul([-7,2],[24,3]), [-174, 27]);

From 47104bcfe034f2b5838578d5bbce521f61509b10 Mon Sep 17 00:00:00 2001
From: Adrian Mariano <avm4@cornell.edu>
Date: Fri, 2 Apr 2021 20:44:11 -0400
Subject: [PATCH 11/18] remove echo

---
 paths.scad | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/paths.scad b/paths.scad
index e7f765c..6db525a 100644
--- a/paths.scad
+++ b/paths.scad
@@ -1244,7 +1244,7 @@ module path_spread(path, n, spacing, sp=undef, rotate_children=true, closed=fals
             is_def(n)? range(s=sp, e=length, n=n) :
             range(s=sp, step=spacing, e=length)
         )
-      : is_def(n) && is_undef(spacing)? ( let(a=echo(n=n))  // N alone given
+      : is_def(n) && is_undef(spacing)? (            // N alone given
             closed ? rangex(s=0, e=length, n=n)
                    : range(s=0, e=length, n=n)
         )

From 56ccca140d5005cbb2208cdb42752cf0e1acd4e2 Mon Sep 17 00:00:00 2001
From: github-actions <github-actions@github.com>
Date: Sat, 3 Apr 2021 02:20:37 +0000
Subject: [PATCH 12/18] Bump release version.

---
 version.scad | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/version.scad b/version.scad
index d38bcfa..a227524 100644
--- a/version.scad
+++ b/version.scad
@@ -6,7 +6,7 @@
 //////////////////////////////////////////////////////////////////////
 
 
-BOSL_VERSION = [2,0,598];
+BOSL_VERSION = [2,0,599];
 
 
 // Section: BOSL Library Version Functions

From a05af703f9dee3ef7f2797c7345b2e4408d89b4c Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 6 Apr 2021 16:57:26 -0700
Subject: [PATCH 13/18] Added is_func()

---
 common.scad | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/common.scad b/common.scad
index ab24380..ba05fc8 100644
--- a/common.scad
+++ b/common.scad
@@ -185,6 +185,19 @@ function valid_range(x) =
          : ( x[1]<0 && x[0]>=x[2] ) );
 
 
+// Function: is_func()
+// Usage:
+//   bool = is_func(x);
+// Description:
+//   Returns true if OpenSCAD supports function literals, and the given item is one.
+// Arguments:
+//   x = The value to check against.
+// Example:
+//   f = function (a) a==2;
+//   bool = is_func(f);  // Returns: true
+function is_func(x) = version_num()>20210000 && is_function(x);
+
+
 // Function: is_consistent()
 // Usage:
 //   bool = is_consistent(list, <pattern>);

From b424bad5c21080c87223bb82389e706a5c5433ee Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 6 Apr 2021 16:59:56 -0700
Subject: [PATCH 14/18] Added lerpn().  Removed modrange().  any(), all(), and
 count_true() can now be given function literals.

---
 math.scad | 168 +++++++++++++++++++++++++++++++-----------------------
 1 file changed, 98 insertions(+), 70 deletions(-)

diff --git a/math.scad b/math.scad
index 2297a29..9e4f73a 100644
--- a/math.scad
+++ b/math.scad
@@ -174,6 +174,31 @@ function lerp(a,b,u) =
     [for (v = u) (1-v)*a + v*b ];
 
 
+// Function: lerpn()
+// Usage:
+//   x = lerpn(a, b, n);
+//   x = lerpn(a, b, n, <endpoint>);
+// Description:
+//   Returns exactly `n` values, linearly interpolated between `a` and `b`.
+//   If `endpoint` is true, then the last value will exactly equal `b`.
+//   If `endpoint` is false, then the last value will about `a+(b-a)*(1-1/n)`.
+// Arguments:
+//   a = First value or vector.
+//   b = Second value or vector.
+//   n = The number of values to return.
+//   endpoint = If true, the last value will be exactly `b`.  If false, the last value will be one step less.
+// Examples:
+//   l = lerpn(-4,4,9);        // Returns: [-4,-3,-2,-1,0,1,2,3,4]
+//   l = lerpn(-4,4,8,false);  // Returns: [-4,-3,-2,-1,0,1,2,3]
+//   l = lerpn(0,1,6);         // Returns: [0, 0.2, 0.4, 0.6, 0.8, 1]
+//   l = lerpn(0,1,5,false);   // Returns: [0, 0.2, 0.4, 0.6, 0.8]
+function lerpn(a,b,n,endpoint=true) =
+    assert(same_shape(a,b), "Bad or inconsistent inputs to lerp")
+    assert(is_int(n))
+    assert(is_bool(endpoint))
+    let( d = n - (endpoint? 1 : 0) )
+    [for (i=[0:1:n-1]) let(u=i/d) (1-u)*a + u*b];
+
 
 // Section: Undef Safe Math
 
@@ -434,32 +459,6 @@ function modang(x) =
     let(xx = posmod(x,360)) xx<180? xx : xx-360;
 
 
-// Function: modrange()
-// Usage:
-//   modrange(x, y, m, <step>)
-// Description:
-//   Returns a normalized list of numbers from `x` to `y`, by `step`, modulo `m`.  Wraps if `x` > `y`.
-// Arguments:
-//   x = The start value to constrain.
-//   y = The end value to constrain.
-//   m = Modulo value.
-//   step = Step by this amount.
-// Examples:
-//   modrange(90,270,360, step=45);   // Returns: [90,135,180,225,270]
-//   modrange(270,90,360, step=45);   // Returns: [270,315,0,45,90]
-//   modrange(90,270,360, step=-45);  // Returns: [90,45,0,315,270]
-//   modrange(270,90,360, step=-45);  // Returns: [270,225,180,135,90]
-function modrange(x, y, m, step=1) =
-    assert( is_finite(x+y+step+m) && !approx(m,0), "Input must be finite numbers and the module value cannot be zero." )
-    let(
-        a = posmod(x, m),
-        b = posmod(y, m),
-        c = step>0? (a>b? b+m : b) 
-            : (a<b? b-m : b)
-    ) [for (i=[a:step:c]) (i%m+m)%m ];
-
-
-
 // Section: Random Number Generation
 
 // Function: rand_int()
@@ -1216,72 +1215,85 @@ function compare_vals(a, b) =
 //   a = First list to compare.
 //   b = Second list to compare.
 function compare_lists(a, b) =
-    a==b? 0 
-    :   let(
-          cmps = [ for(i=[0:1:min(len(a),len(b))-1]) 
-                      let( cmp = compare_vals(a[i],b[i]) )
-                      if(cmp!=0) cmp 
-                 ]
-           ) 
-        cmps==[]? (len(a)-len(b)) : cmps[0];
+    a==b? 0 :
+    let(
+        cmps = [
+            for (i = [0:1:min(len(a),len(b))-1])
+            let( cmp = compare_vals(a[i],b[i]) )
+            if (cmp!=0) cmp
+        ]
+    )
+    cmps==[]? (len(a)-len(b)) : cmps[0];
 
 
 // Function: any()
 // Usage:
 //   b = any(l);
+//   b = any(l,func);
 // Description:
 //   Returns true if any item in list `l` evaluates as true.
-//   If `l` is a lists of lists, `any()` is applied recursively to each sublist.
 // Arguments:
 //   l = The list to test for true items.
+//   func = An optional function literal of signature (x), returning bool, to test each list item with.
 // Example:
 //   any([0,false,undef]);  // Returns false.
 //   any([1,false,undef]);  // Returns true.
 //   any([1,5,true]);       // Returns true.
-//   any([[0,0], [0,0]]);   // Returns false.
+//   any([[0,0], [0,0]]);   // Returns true.
 //   any([[0,0], [1,0]]);   // Returns true.
-function any(l) =
+function any(l, func) =
     assert(is_list(l), "The input is not a list." )
-    _any(l);
+    assert(func==undef || is_func(func))
+    is_func(func)
+      ? _any_func(l, func)
+      : _any_bool(l);
 
-function _any(l, i=0, succ=false) =
-    (i>=len(l) || succ)? succ :
-    _any(
-        l, i+1, 
-        succ = is_list(l[i]) ? _any(l[i]) : !(!l[i])
-    );
+function _any_func(l, func, i=0, out=false) =
+    i >= len(l) || out? out :
+    _any_func(l, func, i=i+1, out=out || func(l[i]));
+
+function _any_bool(l, i=0, out=false) =
+    i >= len(l) || out? out :
+    _any_bool(l, i=i+1, out=out || l[i]);
 
 
 // Function: all()
 // Usage:
 //   b = all(l);
+//   b = all(l,func);
 // Description:
-//   Returns true if all items in list `l` evaluate as true.
-//   If `l` is a lists of lists, `all()` is applied recursively to each sublist.
+//   Returns true if all items in list `l` evaluate as true.  If `func` is given a function liteal
+//   of signature (x), returning bool, then that function literal is evaluated for each list item.
 // Arguments:
 //   l = The list to test for true items.
+//   func = An optional function literal of signature (x), returning bool, to test each list item with.
 // Example:
 //   all([0,false,undef]);  // Returns false.
 //   all([1,false,undef]);  // Returns false.
 //   all([1,5,true]);       // Returns true.
-//   all([[0,0], [0,0]]);   // Returns false.
-//   all([[0,0], [1,0]]);   // Returns false.
+//   all([[0,0], [0,0]]);   // Returns true.
+//   all([[0,0], [1,0]]);   // Returns true.
 //   all([[1,1], [1,1]]);   // Returns true.
-function all(l) =
-    assert( is_list(l), "The input is not a list." )
-    _all(l);
+function all(l, func) =
+    assert(is_list(l), "The input is not a list.")
+    assert(func==undef || is_func(func))
+    is_func(func)
+      ? _all_func(l, func)
+      : _all_bool(l);
 
-function _all(l, i=0, fail=false) =
-    (i>=len(l) || fail)? !fail :
-    _all(
-        l, i+1,
-        fail = is_list(l[i]) ? !_all(l[i]) : !l[i]
-    ) ;
+function _all_func(l, func, i=0, out=true) =
+    i >= len(l) || !out? out :
+    _all_func(l, func, i=i+1, out=out && func(l[i]));
+
+function _all_bool(l, i=0, out=true) =
+    i >= len(l) || !out? out :
+    _all_bool(l, i=i+1, out=out && l[i]);
 
 
 // Function: count_true()
 // Usage:
-//   n = count_true(l)
+//   n = count_true(l,<nmax=>)
+//   n = count_true(l,func,<nmax=>)
 // Description:
 //   Returns the number of items in `l` that evaluate as true.
 //   If `l` is a lists of lists, this is applied recursively to each
@@ -1289,24 +1301,38 @@ function _all(l, i=0, fail=false) =
 //   in all recursive sublists.
 // Arguments:
 //   l = The list to test for true items.
-//   nmax = If given, stop counting if `nmax` items evaluate as true.
+//   func = An optional function literal of signature (x), returning bool, to test each list item with.
+//   ---
+//   nmax = Max number of true items to count.  Default: `undef` (no limit)
 // Example:
 //   count_true([0,false,undef]);  // Returns 0.
 //   count_true([1,false,undef]);  // Returns 1.
 //   count_true([1,5,false]);      // Returns 2.
 //   count_true([1,5,true]);       // Returns 3.
-//   count_true([[0,0], [0,0]]);   // Returns 0.
-//   count_true([[0,0], [1,0]]);   // Returns 1.
-//   count_true([[1,1], [1,1]]);   // Returns 4.
-//   count_true([[1,1], [1,1]], nmax=3);  // Returns 3.
-function _count_true_rec(l, nmax, _cnt=0, _i=0) =
-    _i>=len(l) || (is_num(nmax) && _cnt>=nmax)? _cnt :
-    _count_true_rec(l, nmax, _cnt=_cnt+(l[_i]?1:0), _i=_i+1);
+//   count_true([[0,0], [0,0]]);   // Returns 2.
+//   count_true([[0,0], [1,0]]);   // Returns 2.
+//   count_true([[1,1], [1,1]]);   // Returns 2.
+//   count_true([[1,1], [1,1]], nmax=1);  // Returns 1.
+function count_true(l, func, nmax) = 
+    assert(is_list(l))
+    assert(func==undef || is_func(func))
+    is_func(func)
+      ? _count_true_func(l, func, nmax)
+      : _count_true_bool(l, nmax);
 
-function count_true(l, nmax) = 
-    is_undef(nmax)? len([for (x=l) if(x) 1]) :
-    !is_list(l) ? ( l? 1: 0) :
-    _count_true_rec(l, nmax);
+function _count_true_func(l, func, nmax, i=0, out=0) =
+    i >= len(l) || (nmax!=undef && out>=nmax) ? out :
+    _count_true_func(
+        l, func, nmax, i = i + 1,
+        out = out + (func(l[i])? 1:0)
+    );
+
+function _count_true_bool(l, nmax, i=0, out=0) =
+    i >= len(l) || (nmax!=undef && out>=nmax) ? out :
+    _count_true_bool(
+        l, nmax, i = i + 1,
+        out = out + (l[i]? 1:0)
+    );
 
 
 
@@ -1573,6 +1599,7 @@ function c_ident(n) = [for (i = [0:1:n-1]) [for (j = [0:1:n-1]) (i==j)?[1,0]:[0,
 function c_norm(z) = norm_fro(z);
 
 
+
 // Section: Polynomials
 
 // Function: quadratic_roots()
@@ -1624,6 +1651,7 @@ function polynomial(p,z,k,total) =
   : k==len(p) ? total
   : polynomial(p,z,k+1, is_num(z) ? total*z+p[k] : c_mul(total,z)+[p[k],0]);
 
+
 // Function: poly_mult()
 // Usage:
 //   x = polymult(p,q)

From b370e2540bb3367f4d8f489f4478bfa0aa7b27d2 Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 6 Apr 2021 17:00:40 -0700
Subject: [PATCH 15/18] Added function line_of().

---
 distributors.scad | 87 ++++++++++++++++++++++++++---------------------
 1 file changed, 48 insertions(+), 39 deletions(-)

diff --git a/distributors.scad b/distributors.scad
index fde784d..588acb8 100644
--- a/distributors.scad
+++ b/distributors.scad
@@ -40,24 +40,30 @@ module move_copies(a=[[0,0,0]])
 }
 
 
-// Module: line_of()
+// Function&Module: line_of()
 //
 // Usage: Spread `n` copies by a given spacing
-//   line_of(spacing, [n], [p1]) ...
+//   line_of(spacing, <n>, <p1=>) ...
 // Usage: Spread copies every given spacing along the line
-//   line_of(spacing, l, [p1]) ...
+//   line_of(spacing, <l=>, <p1=>) ...
 // Usage: Spread `n` copies along the length of the line
-//   line_of(l, [n], [p1]) ...
+//   line_of(<n=>, <l=>, <p1=>) ...
 // Usage: Spread `n` copies along the line from `p1` to `p2`
-//   line_of(p1, p2, [n]) ...
+//   line_of(<n=>, <p1=>, <p2=>) ...
 // Usage: Spread copies every given spacing, centered along the line from `p1` to `p2`
-//   line_of(p1, p2, spacing) ...
-//
+//   line_of(<spacing>, <p1=>, <p2=>) ...
+// Usage: As a function
+//   pts = line_of(<spacing>, <n>, <p1=>);
+//   pts = line_of(<spacing>, <l=>, <p1=>);
+//   pts = line_of(<n=>, <l=>, <p1=>);
+//   pts = line_of(<n=>, <p1=>, <p2=>);
+//   pts = line_of(<spacing>, <p1=>, <p2=>);
 // Description:
-//   Copies `children()` at one or more evenly spread positions along a line. By default, the line
-//   will be centered at the origin, unless the starting point `p1` is given.  The line will be
-//   pointed towards `RIGHT` (X+) unless otherwise given as a vector in `l`, `spacing`, or `p1`/`p2`.
-//   The spread is specified in one of several ways:
+//   When called as a function, returns a list of points at evenly spread positions along a line.
+//   When called as a module, copies `children()` at one or more evenly spread positions along a line.
+//   By default, the line will be centered at the origin, unless the starting point `p1` is given.
+//   The line will be pointed towards `RIGHT` (X+) unless otherwise given as a vector in `l`,
+//   `spacing`, or `p1`/`p2`.  The spread is specified in one of several ways:
 //   .
 //   If You Know...                   | Then Use Something Like...
 //   -------------------------------- | --------------------------------
@@ -74,6 +80,7 @@ module move_copies(a=[[0,0,0]])
 // Arguments:
 //   spacing = Either the scalar spacing distance along the X+ direction, or the vector giving both the direction and spacing distance between each set of copies.
 //   n = Number of copies to distribute along the line. (Default: 2)
+//   ---
 //   l = Either the scalar length of the line, or a vector giving both the direction and length of the line.
 //   p1 = If given, specifies the starting point of the line.
 //   p2 = If given with `p1`, specifies the ending point of line, and indirectly calculates the line length.
@@ -102,40 +109,42 @@ module move_copies(a=[[0,0,0]])
 //       cube(size=[1,3,1],center=true);
 //       cube(size=[3,1,1],center=true);
 //   }
+// Example(2D):
+//   pts = line_of([10,5],n=5);
+//   move_copies(pts) circle(d=2);
 module line_of(spacing, n, l, p1, p2)
 {
-    assert(is_undef(spacing) || is_finite(spacing) || is_vector(spacing));
-    assert(is_undef(n) || is_finite(n));
-    assert(is_undef(l) || is_finite(l) || is_vector(l));
-    assert(is_undef(p1) || is_vector(p1));
-    assert(is_undef(p2) || is_vector(p2));
-    ll = (
-        !is_undef(l)? scalar_vec3(l, 0) :
-        (!is_undef(spacing) && !is_undef(n))? (n * scalar_vec3(spacing, 0)) :
-        (!is_undef(p1) && !is_undef(p2))? point3d(p2-p1) :
-        undef
-    );
-    cnt = (
-        !is_undef(n)? n :
-        (!is_undef(spacing) && !is_undef(ll))? floor(norm(ll) / norm(scalar_vec3(spacing, 0)) + 1.000001) :
-        2
-    );
-    spc = (
-        cnt<=1? [0,0,0] :
-        is_undef(spacing)? (ll/(cnt-1)) :
-        is_num(spacing) && !is_undef(ll)? (ll/(cnt-1)) :
-        scalar_vec3(spacing, 0)
-    );
-    assert(!is_undef(cnt), "Need two of `spacing`, 'l', 'n', or `p1`/`p2` arguments in `line_of()`.");
-    spos = !is_undef(p1)? point3d(p1) : -(cnt-1)/2 * spc;
-    for (i=[0:1:cnt-1]) {
-        pos = i * spc + spos;
-        $pos = pos;
+    pts = line_of(spacing=spacing, n=n, l=l, p1=p1, p2=p2);
+    for (i=idx(pts)) {
         $idx = i;
-        translate(pos) children();
+        $pos = pts[i];
+        translate($pos) children();
     }
 }
 
+function line_of(spacing, n, l, p1, p2) =
+    assert(is_undef(spacing) || is_finite(spacing) || is_vector(spacing))
+    assert(is_undef(n) || is_finite(n))
+    assert(is_undef(l) || is_finite(l) || is_vector(l))
+    assert(is_undef(p1) || is_vector(p1))
+    assert(is_undef(p2) || is_vector(p2))
+    let(
+        ll = !is_undef(l)? scalar_vec3(l, 0) :
+            (!is_undef(spacing) && !is_undef(n))? (n * scalar_vec3(spacing, 0)) :
+            (!is_undef(p1) && !is_undef(p2))? point3d(p2-p1) :
+            undef,
+        cnt = !is_undef(n)? n :
+            (!is_undef(spacing) && !is_undef(ll))? floor(norm(ll) / norm(scalar_vec3(spacing, 0)) + 1.000001) :
+            2,
+        spc = cnt<=1? [0,0,0] :
+            is_undef(spacing)? (ll/(cnt-1)) :
+            is_num(spacing) && !is_undef(ll)? (ll/(cnt-1)) :
+            scalar_vec3(spacing, 0)
+    )
+    assert(!is_undef(cnt), "Need two of `spacing`, 'l', 'n', or `p1`/`p2` arguments in `line_of()`.")
+    let( spos = !is_undef(p1)? point3d(p1) : -(cnt-1)/2 * spc )
+    [for (i=[0:1:cnt-1]) i * spc + spos];
+
 
 // Module: xcopies()
 //

From 2b78f82063350ffd2d9bfea026c15822d8c33935 Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 6 Apr 2021 17:01:41 -0700
Subject: [PATCH 16/18] Regressions fixes for any()/all()/count_true() changes.

---
 tests/test_math.scad | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/tests/test_math.scad b/tests/test_math.scad
index e943756..5b599bb 100644
--- a/tests/test_math.scad
+++ b/tests/test_math.scad
@@ -299,15 +299,6 @@ module test_modang() {
 test_modang();
 
 
-module test_modrange() {
-    assert_equal(modrange(-5,5,3), [1,2]);
-    assert_equal(modrange(-1,4,3), [2,0,1]);
-    assert_equal(modrange(1,8,10,step=2), [1,3,5,7]);
-    assert_equal(modrange(5,12,10,step=2), [5,7,9,1]);
-}
-test_modrange();
-
-
 module test_sqr() {
     assert_equal(sqr(-3), 9);
     assert_equal(sqr(0), 0);
@@ -738,11 +729,14 @@ module test_any() {
     assert_equal(any([0,false,undef]), false);
     assert_equal(any([1,false,undef]), true);
     assert_equal(any([1,5,true]), true);
-    assert_equal(any([[0,0], [0,0]]), false);
+    assert_equal(any([[0,0], [0,0]]), true);
     assert_equal(any([[0,0], [1,0]]), true);
     assert_equal(any([[false,false],[[false,[false],[[[true]]]],false],[false,false]]), true);
-    assert_equal(any([[false,false],[[false,[false],[[[false]]]],false],[false,false]]), false);
+    assert_equal(any([[false,false],[[false,[false],[[[false]]]],false],[false,false]]), true);
     assert_equal(any([]), false);
+    assert_equal(any([1,3,5,7,9], function (a) a%2==0),false);
+    assert_equal(any([1,3,6,7,9], function (a) a%2==0),true);
+    assert_equal(any([1,3,5,7,9], function (a) a%2!=0),true);
 }
 test_any();
 
@@ -751,12 +745,15 @@ module test_all() {
     assert_equal(all([0,false,undef]), false);
     assert_equal(all([1,false,undef]), false);
     assert_equal(all([1,5,true]), true);
-    assert_equal(all([[0,0], [0,0]]), false);
-    assert_equal(all([[0,0], [1,0]]), false);
+    assert_equal(all([[0,0], [0,0]]), true);
+    assert_equal(all([[0,0], [1,0]]), true);
     assert_equal(all([[1,1], [1,1]]), true);
-    assert_equal(all([[true,true],[[true,[true],[[[true]]]],true],[true,true]]), true);    
-    assert_equal(all([[true,true],[[true,[true],[[[false]]]],true],[true,true]]), false);
+    assert_equal(all([[true,true],[[true,[true],[[[true]]]],true],[true,true]]), true);
+    assert_equal(all([[true,true],[[true,[true],[[[false]]]],true],[true,true]]), true);
     assert_equal(all([]), true);
+    assert_equal(all([1,3,5,7,9], function (a) a%2==0),false);
+    assert_equal(all([1,3,6,8,9], function (a) a%2==0),false);
+    assert_equal(all([1,3,5,7,9], function (a) a%2!=0),true);
 }
 test_all();
 
@@ -770,6 +767,9 @@ module test_count_true() {
     assert_equal(count_true([[0,0], [1,0]]), 2);
     assert_equal(count_true([[1,1], [1,1]]), 2);
     assert_equal(count_true([1,1,1,1,1], nmax=3), 3);
+    assert_equal(count_true([1,3,5,7,9], function (a) a%2==0),0);
+    assert_equal(count_true([1,3,6,8,9], function (a) a%2==0),2);
+    assert_equal(count_true([1,3,5,7,9], function (a) a%2!=0),5);
 }
 test_count_true();
 
@@ -789,6 +789,7 @@ module test_factorial() {
 }
 test_factorial();
 
+
 module test_binomial() {
     assert_equal(binomial(1), [1,1]);
     assert_equal(binomial(2), [1,2,1]);
@@ -797,6 +798,7 @@ module test_binomial() {
 }
 test_binomial();
 
+
 module test_binomial_coefficient() {
     assert_equal(binomial_coefficient(2,1), 2);
     assert_equal(binomial_coefficient(3,2), 3);
@@ -815,8 +817,8 @@ module test_gcd() {
     assert_equal(gcd(39, 101),1);
     assert_equal(gcd(15,-25), 5);
     assert_equal(gcd(-15,25), 5);
-    assert_equal(gcd(5,0),5);
-    assert_equal(gcd(0,5),5);
+    assert_equal(gcd(5,0), 5);
+    assert_equal(gcd(0,5), 5);
 }
 test_gcd();
 

From f07f5b53c106869caad2ae964b551de3d2b5380b Mon Sep 17 00:00:00 2001
From: Garth Minette <revarbat@gmail.com>
Date: Tue, 6 Apr 2021 17:03:18 -0700
Subject: [PATCH 17/18] Added list().  Enable using function literals with
 find_first_match().

---
 arrays.scad | 40 +++++++++++++++++++++++++++++++++-------
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/arrays.scad b/arrays.scad
index 7d85d8c..c143001 100644
--- a/arrays.scad
+++ b/arrays.scad
@@ -200,6 +200,24 @@ function list_tail(list, from=1) =
    list;
 
 
+// Function: list()
+// Topics: List Handling, Type Conversion
+// Usage:
+//   list = list(l)
+// Description:
+//   Expands a range into a full list.  If given a list, returns it verbatim.
+//   If given a string, explodes it into a list of single letters.
+// Arguments:
+//   l = The value to expand.
+// See Also: scalar_vec3(), force_list(), range(), rangex()
+// Example:
+//   l1 = list([3:2:9]);  // Returns: [3,5,7,9]
+//   l2 = list([3,4,5]);  // Returns: [3,4,5]
+//   l3 = list("Foo");    // Returns: ["F","o","o"]
+//   l4 = list(23);       // Returns: [23]
+function list(l) = is_list(l)? l : [for (x=l) x];
+
+
 // Function: force_list()
 // Usage:
 //   list = force_list(value, <n>, <fill>);
@@ -274,20 +292,28 @@ function in_list(val,list,idx) =
 // Description:
 //   Finds the first item in `list` that matches `val`, returning the index.
 // Arguments:
-//   val = The value to search for.
+//   val = The value to search for.  If given a function literal of signature `function (x)`, uses that function to check list items.  Returns true for a match.
 //   list = The list to search through.
 //   ---
 //   start = The index to start searching from.
 //   all = If true, returns a list of all matching item indices.
 //   eps = The maximum allowed floating point rounding error for numeric comparisons.
 function find_first_match(val, list, start=0, all=false, eps=EPSILON) =
-    all? [for (i=[start:1:len(list)-1]) if(val==list[i] || approx(val, list[i], eps=eps)) i] :
+    all? [
+        for (i=[start:1:len(list)-1])
+        if (
+            (!is_func(val) && approx(val, list[i], eps=eps)) ||
+            (is_func(val) && val(list[i]))
+        ) i
+    ] :
     __find_first_match(val, list, eps=eps, i=start);
 
 function __find_first_match(val, list, eps, i=0) =
     i >= len(list)? undef :
-    approx(val, list[i], eps=eps)? i :
-    __find_first_match(val, list, eps=eps, i=i+1);
+    (
+        (!is_func(val) && approx(val, list[i], eps=eps)) ||
+        (is_func(val) && val(list[i]))
+    )? i : __find_first_match(val, list, eps=eps, i=i+1);
 
 
 // Function: min_index()
@@ -425,7 +451,7 @@ function range(n, s=0, e, step) =
     let( step = (n!=undef && e!=undef)? (e-s)/(n-1) : default(step,1) )
     is_undef(e)
       ? assert( is_consistent([s, step]), "Incompatible data.")
-        [for (i=[0:1:n-1]) s+step*i ]
+        [for (i=[0:1:n-1]) s+step*i]
       : assert( is_vector([s,step,e]), "Start `s`, step `step` and end `e` must be numbers.")
         [for (v=[s:step:e]) v] ;
     
@@ -468,10 +494,10 @@ function rangex(n, s=0, e, step) =
     let( step = (n!=undef && e!=undef)? (e-s)/n : default(step,1) )
     is_undef(e)
       ? assert( is_consistent([s, step]), "Incompatible data.")
-        [for (i=[0:1:n-1]) s+step*i ]
+        [for (i=[0:1:n-1]) s+step*i]
       : assert( is_vector([s,step,e]), "Start `s`, step `step` and end `e` must be numbers.")
         let(steps=floor((e-s)/step+0.5))
-        [for (i=[0:1:steps-1]) s+step*i ];
+        [for (i=[0:1:steps-1]) s+step*i];
     
 
 

From b1ab140e3c12ee3da834dbb417de726b8818c263 Mon Sep 17 00:00:00 2001
From: github-actions <github-actions@github.com>
Date: Wed, 7 Apr 2021 00:11:32 +0000
Subject: [PATCH 18/18] Bump release version.

---
 version.scad | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/version.scad b/version.scad
index a227524..168b763 100644
--- a/version.scad
+++ b/version.scad
@@ -6,7 +6,7 @@
 //////////////////////////////////////////////////////////////////////
 
 
-BOSL_VERSION = [2,0,599];
+BOSL_VERSION = [2,0,600];
 
 
 // Section: BOSL Library Version Functions