BOSL2/strings.scad
2020-03-05 03:28:41 -08:00

463 lines
19 KiB
OpenSCAD

// Section: String Operations
//-----------------------------------------------------------------------------
// Function: substr()
// Usage:
// substr(str, [pos], [len])
// Description:
// Returns a substring from a string start at position `pos` with length `len`, or
// if `len` isn't given, the rest of the string.
// Arguments:
// str = string to operate on
// pos = starting index of substring, or vector of first and last position. Default: 0
// len = length of substring, or omit it to get the rest of the string. If len is less than zero the emptry string is returned.
// Example:
// substr("abcdefg",3,3); // Returns "def"
// substr("abcdefg",2); // Returns "cdefg"
// substr("abcdefg",len=3); // Returns "abc"
// substr("abcdefg",[2,4]); // Returns "cde"
// substr("abcdefg",len=-2); // Returns ""
function substr(str, pos=0, len=undef) =
is_list(pos) ? _substr(str, pos[0], pos[1]-pos[0]+1) :
len == undef ? _substr(str, pos, len(str)-pos) :
_substr(str,pos,len);
function _substr(str,pos,len,substr="") =
len <= 0 || pos>=len(str) ? substr :
_substr(str, pos+1, len-1, str(substr, str[pos]));
// Function suffix()
// Usage:
// suffix(str,len)
// Description:
// Returns the last `len` characters from the input string
function suffix(str,len) = substr(str, len(str)-len,len);
// Function: str_join()
// Usage:
// str_join(list, [sep])
// Description:
// Returns the concatenation of a list of strings, optionally with a
// separator string inserted between each string on the list.
// Arguments:
// list = list of strings to concatenate
// sep = separator string to insert. Default: ""
// Example:
// str_join(["abc","def","ghi"]); // Returns "abcdefghi"
// str_join(["abc","def","ghi"], " + "); // Returns "abc + def + ghi"
function str_join(list,sep="",_i=0, _result="") =
_i >= len(list)-1 ? (_i==len(list) ? _result : str(_result,list[_i])) :
str_join(list,sep,_i+1,str(_result,list[_i],sep));
// Function: downcase()
// Usage:
// downcase(str)
// Description:
// Returns the string with the standard ASCII upper case letters A-Z replaced
// by their lower case versions.
// Arguments:
// str = string to convert
// Example:
// downcase("ABCdef"); // Returns "abcdef"
function downcase(str) =
str_join([for(char=str) let(code=ord(char)) code>=65 && code<=90 ? chr(code+32) : char]);
// Function: str_int()
// Usage:
// str_int(str, [base])
// Description:
// Converts a string into an integer with any base up to 16. Returns NaN if
// conversion fails. Digits above 9 are represented using letters A-F in either
// upper case or lower case.
// Arguments:
// str = string to convert
// base = base for conversion, from 2-16. Default: 10
// Example:
// str_int("349"); // Returns 349
// str_int("-37"); // Returns -37
// str_int("+97"); // Returns 97
// str_int("43.9"); // Returns nan
// str_int("1011010",2); // Returns 90
// str_int("13",2); // Returns nan
// str_int("dead",16); // Returns 57005
// str_int("CEDE", 16); // Returns 52958
// str_int(""); // Returns 0
function str_int(str,base=10) =
str==undef ? undef :
len(str)==0 ? 0 :
let(str=downcase(str))
str[0] == "-" ? -_str_int_recurse(substr(str,1),base,len(str)-2) :
str[0] == "+" ? _str_int_recurse(substr(str,1),base,len(str)-2) :
_str_int_recurse(str,base,len(str)-1);
function _str_int_recurse(str,base,i) =
let(
digit = search(str[i],"0123456789abcdef"),
last_digit = digit == [] || digit[0] >= base ? (0/0) : digit[0]
) i==0 ? last_digit :
_str_int_recurse(str,base,i-1)*base + last_digit;
// Function: str_float()
// Usage:
// str_float(str)
// Description:
// Converts a string to a floating point number. Returns NaN if the
// conversion fails.
// Arguments:
// str = string to convert
// Example:
// str_float("44"); // Returns 44
// str_float("3.4"); // Returns 3.4
// str_float("-99.3332"); // Returns -99.3332
// str_float("3.483e2"); // Returns 348.3
// str_float("-44.9E2"); // Returns -4490
// str_float("7.342e-4"); // Returns 0.0007342
// str_float(""); // Returns 0
function str_float(str) =
str==undef ? undef :
len(str) == 0 ? 0 :
in_list(str[1], ["+","-"]) ? (0/0) : // Don't allow --3, or +-3
str[0]=="-" ? -str_float(substr(str,1)) :
str[0]=="+" ? str_float(substr(str,1)) :
let(esplit = str_split(str,"eE") )
len(esplit)==2 ? str_float(esplit[0]) * pow(10,str_int(esplit[1])) :
let( dsplit = str_split(str,["."]))
str_int(dsplit[0])+str_int(dsplit[1])/pow(10,len(dsplit[1]));
// Function: str_frac()
// Usage:
// str_frac(str,[mixed],[improper],[signed])
// Description:
// Converts a string fraction to a floating point number. A string fraction has the form `[-][# ][#/#]` where each `#` is one or more of the
// digits 0-9, and there is an optional sign character at the beginning.
// The full form is a sign character and an integer, followed by exactly one space, followed by two more
// integers separated by a "/" character. The leading integer and
// space can be omitted or the trailing fractional part can be omitted. If you set `mixed` to false then the leading integer part is not
// accepted and the input must include a slash. If you set `improper` to false then the fractional part must be a proper fraction, where
// the numerator is smaller than the denominator. If you set `signed` to false then the leading sign character is not permitted.
// The empty string evaluates to zero. Any invalid string evaluates to NaN.
// Arguments:
// str = string to convert
// mixed = set to true to accept mixed fractions, false to reject them. Default: true
// improper = set to true to accept improper fractions, false to reject them. Default: true
// signed = set to true to accept a leading sign character, false to reject. Default: true
// Example:
// str_frac("3/4"); // Returns 0.75
// str_frac("-77/9"); // Returns -8.55556
// str_frac("+1/3"); // Returns 0.33333
// str_frac("19"); // Returns 19
// str_frac("2 3/4"); // Returns 2.75
// str_frac("-2 12/4"); // Returns -5
// str_frac(""); // Returns 0
// str_frac("3/0"); // Returns inf
// str_frac("0/0"); // Returns nan
// str_frac("-77/9",improper=false); // Returns nan
// str_frac("-2 12/4",improper=false); // Returns nan
// str_frac("-2 12/4",signed=false); // Returns nan
// str_frac("-2 12/4",mixed=false); // Returns nan
// str_frac("2 1/4",mixed=false); // Returns nan
function str_frac(str,mixed=true,improper=true,signed=true) =
str == undef ? undef :
len(str)==0 ? 0 :
signed && str[0]=="-" ? -str_frac(substr(str,1),mixed=mixed,improper=improper,signed=false) :
signed && str[0]=="+" ? str_frac(substr(str,1),mixed=mixed,improper=improper,signed=false) :
mixed ? (
str_find(str," ")>0 || is_undef(str_find(str,"/"))? (
let(whole = str_split(str,[" "]))
_str_int_recurse(whole[0],10,len(whole[0])-1) + str_frac(whole[1], mixed=false, improper=improper, signed=false)
) : str_frac(str,mixed=false, improper=improper)
) : (
let(split = str_split(str,"/"))
len(split)!=2 ? (0/0) :
let(
numerator = _str_int_recurse(split[0],10,len(split[0])-1),
denominator = _str_int_recurse(split[1],10,len(split[1])-1)
) !improper && numerator>=denominator? (0/0) :
denominator<0 ? (0/0) : numerator/denominator
);
// Function: str_num()
// Usage:
// str_num(str)
// Description:
// Converts a string to a number. The string can be either a fraction (two integers separated by a "/") or a floating point number.
// Returns NaN if the conversion fails.
// Example:
// str_num("3/4"); // Returns 0.75
// str_num("3.4e-2"); // Returns 0.034
function str_num(str) =
str == undef ? undef :
let( val = str_frac(str) )
val == val ? val :
str_float(str);
// Function: str_split()
// Usage:
// str_split(str, sep, [keep_nulls])
// Description:
// Breaks an input string into substrings using a separator or list of separators. If keep_nulls is true
// then two sequential separator characters produce an empty string in the output list. If keep_nulls is false
// then no empty strings are included in the output list.
//
// If sep is a single string then each character in sep is treated as a delimiting character and the input string is
// split at every delimiting character. Empty strings can occur whenever two delimiting characters are sequential.
// If sep is a list of strings then the input string is split sequentially using each string from the list in order.
// If keep_nulls is true then the output will have length equal to `len(sep)+1`, possibly with trailing null strings
// if the string runs out before the separator list.
// Arguments
// str = string to split
// sep = a string or list of strings to use for the separator
// keep_nulls = boolean value indicating whether to keep null strings in the output list. Default: true
// Example:
// str_split("abc+def-qrs*iop","*-+"); // Returns ["abc", "def", "qrs", "iop"]
// str_split("abc+*def---qrs**iop+","*-+");// Returns ["abc", "", "def", "", "", "qrs", "", "iop", ""]
// str_split("abc def"," "); // Returns ["abc", "", "", "", "", "", "def"]
// str_split("abc def"," ",keep_nulls=false); // Returns ["abc", "def"]
// str_split("abc+def-qrs*iop",["+","-","*"]); // Returns ["abc", "def", "qrs", "iop"]
// str_split("abc+def-qrs*iop",["-","+","*"]); // Returns ["abc+def", "qrs*iop", "", ""]
function str_split(str,sep,keep_nulls=true) =
!keep_nulls ? _remove_empty_strs(str_split(str,sep,keep_nulls=true)) :
is_list(sep) ? str_split_recurse(str,sep,i=0,result=[]) :
let( cutpts = concat([-1],sort(flatten(search(sep, str,0))),[len(str)]))
[for(i=[0:len(cutpts)-2]) substr(str,cutpts[i]+1,cutpts[i+1]-cutpts[i]-1)];
function str_split_recurse(str,sep,i,result) =
i == len(sep) ? concat(result,[str]) :
let(
pos = search(sep[i], str),
end = pos==[] ? len(str) : pos[0]
)
str_split_recurse(
substr(str,end+1),
sep, i+1,
concat(result, [substr(str,0,end)])
);
function _remove_empty_strs(list) =
list_remove(list, search([""], list,0)[0]);
// _str_cmp(str,sindex,pattern)
// returns true if the string pattern matches the string
// starting at index position sindex in the string.
//
// This is carefully optimized for speed. Precomputing the length
// cuts run time in half when the string is long. Two other string
// comparison methods were slower.
function _str_cmp(str,sindex,pattern) =
len(str)-sindex <len(pattern)? false :
_str_cmp_recurse(str,sindex,pattern,len(pattern));
function _str_cmp_recurse(str,sindex,pattern,plen,pindex=0,) =
pindex < plen && pattern[pindex]==str[sindex] ? _str_cmp_recurse(str,sindex+1,pattern,plen,pindex+1): (pindex==plen);
// Function: str_find()
// Usage:
// str_find(str,pattern,[last],[all],[start])
// Description:
// Searches input string `str` for the string `pattern` and returns the index or indices of the matches in `str`.
// By default str_find() returns the index of the first match in `str`. If `last` is true then it returns the index of the last match.
// If the pattern is the empty string the first match is at zero and the last match is the last character of the `str`.
// If `start` is set then the search begins at index start, working either forward and backward from that position. If you set `start`
// and `last` is true then the search will find the pattern if it begins at index `start`. If no match exists, returns undef.
// If you set `all` to true then all str_find() returns all of the matches in a list, or an empty list if there are no matches.
// Arguments:
// str = string to search
// pattern = string pattern to search for
// last = set to true to return the last match. Default: false
// all = set to true to return all matches as a list. Overrides last. Default: false
// start = index where the search starts
// Example:
// str_find("abc123def123abc","123"); // Returns 3
// str_find("abc123def123abc","b"); // Returns 1
// str_find("abc123def123abc","1234"); // Returns undef
// str_find("abc",""); // Returns 0
// str_find("abc123def123", "123", start=4); // Returns 9
// str_find("abc123def123abc","123",last=true); // Returns 9
// str_find("abc123def123abc","b",last=true); // Returns 13
// str_find("abc123def123abc","1234",last=true); // Returns undef
// str_find("abc","",last=true); // Returns 2
// str_find("abc123def123", "123", start=8, last=true)); // Returns 3
// str_find("abc123def123abc","123",all=true); // Returns [3,9]
// str_find("abc123def123abc","b",all=true); // Returns [1,13]
// str_find("abc123def123abc","1234",all=true); // Returns []
// str_find("abc","",all=true); // Returns [0,1,2]
function str_find(str,pattern,start=undef,last=false,all=false) =
all? _str_find_all(str,pattern) :
let( start = first_defined([start,last?len(str)-len(pattern):0]) )
pattern==""? start :
last? _str_find_last(str,pattern,start) :
_str_find_first(str,pattern,len(str)-len(pattern),start);
function _str_find_first(str,pattern,max_sindex,sindex) =
sindex<=max_sindex && !_str_cmp(str,sindex, pattern)?
_str_find_first(str,pattern,max_sindex,sindex+1) :
(sindex <= max_sindex ? sindex : undef);
function _str_find_last(str,pattern,sindex) =
sindex>=0 && !_str_cmp(str,sindex, pattern)?
_str_find_last(str,pattern,sindex-1) :
(sindex >=0 ? sindex : undef);
function _str_find_all(str,pattern) =
pattern == "" ? list_range(len(str)) :
[for(i=[0:1:len(str)-len(pattern)]) if (_str_cmp(str,i,pattern)) i];
// Function: starts_with()
// Usage:
// starts_with(str,pattern)
// Description:
// Returns true if the input string `str` starts with the specified string pattern, `pattern`.
// Otherwise returns false.
// Arguments:
// str = string to search
// pattern = string pattern to search for
// Example:
// starts_with("abcdef","abc"); // Returns true
// starts_with("abcdef","def"); // Returns false
// starts_with("abcdef",""); // Returns true
function starts_with(str,pattern) = _str_cmp(str,0,pattern);
// Function: ends_with()
// Usage:
// ends_with(str,pattern)
// Description:
// Returns true if the input string `str` ends with the specified string pattern, `pattern`.
// Otherwise returns false.
// Arguments:
// str = string to search
// pattern = string pattern to search for
// Example:
// ends_with("abcdef","def"); // Returns true
// ends_with("abcdef","de"); // Returns false
// ends_with("abcdef",""); // Returns true
function ends_with(str,pattern) = _str_cmp(str,len(str)-len(pattern),pattern);
function _str_count_leading(s,c,_i=0) =
(_i>=len(s)||!in_list(s[_i],[each c]))? _i :
_str_count_leading(s,c,_i=_i+1);
function _str_count_trailing(s,c,_i=0) =
(_i>=len(s)||!in_list(s[len(s)-1-_i],[each c]))? _i :
_str_count_trailing(s,c,_i=_i+1);
// Function: str_strip_leading()
// Usage:
// str_strip_leading(s,c);
// Description:
// Takes a string `s` and strips off all leading characters that exist in string `c`.
// Arguments:
// s = The string to strip leading characters from.
// c = The string of characters to strip.
// Example:
// str_strip_leading("--##--123--##--","#-"); // Returns: "123--##--"
// str_strip_leading("--##--123--##--","-"); // Returns: "##--123--##--"
// str_strip_leading("--##--123--##--","#"); // Returns: "--##--123--##--"
function str_strip_leading(s,c) = substr(s,pos=_str_count_leading(s,c));
// Function: str_strip_trailing()
// Usage:
// str_strip_trailing(s,c);
// Description:
// Takes a string `s` and strips off all trailing characters that exist in string `c`.
// Arguments:
// s = The string to strip trailing characters from.
// c = The string of characters to strip.
// Example:
// str_strip_trailing("--##--123--##--","#-"); // Returns: "--##--123"
// str_strip_trailing("--##--123--##--","-"); // Returns: "--##--123--##"
// str_strip_trailing("--##--123--##--","#"); // Returns: "--##--123--##--"
function str_strip_trailing(s,c) = substr(s,len=len(s)-_str_count_trailing(s,c));
// Function: str_strip()
// Usage:
// str_strip(s,c);
// Description:
// Takes a string `s` and strips off all leading or trailing characters that exist in string `c`.
// Arguments:
// s = The string to strip leading or trailing characters from.
// c = The string of characters to strip.
// Example:
// str_strip("--##--123--##--","#-"); // Returns: "123"
// str_strip("--##--123--##--","-"); // Returns: "##--123--##"
// str_strip("--##--123--##--","#"); // Returns: "--##--123--##--"
function str_strip(s,c) = str_strip_trailing(str_strip_leading(s,c),c);
// Function: fmti()
// Usage:
// fmti(i, [mindigits]);
// Description:
// Formats an integer number into a string. This can handle larger numbers than `str()`.
// Arguments:
// i = The integer to make a string of.
// mindigits = If the number has fewer than this many digits, pad the front with zeros until it does. Default: 1.
// Example:
// str(123456789012345); // Returns "1.23457e+14"
// fmti(123456789012345); // Returns "123456789012345"
// fmti(-123456789012345); // Returns "-123456789012345"
function fmti(i,mindigits=1) =
i<0? str("-", fmti(-i)) :
let(i=floor(i), e=floor(log(i)))
i==0? "0" :
str_join(
concat(
[for (j=[0:1:mindigits-e-2]) "0"],
[for (j=[e:-1:0]) str(floor(i/pow(10,j)%10))]
)
);
// Function: fmtf()
// Usage:
// fmtf(f,[sig]);
// Description:
// Formats the given floating point number `f` into a string with `sig` significant digits.
// Strips trailing `0`s after the decimal point. Strips trailing decimal point.
// If the number can be represented in `sig` significant digits without a mantissa, it will be.
// If given a list of numbers, recursively prints each item in the list, returning a string like `[3,4,5]`
// Arguments:
// f = The floating point number to format.
// sig = The number of significant digits to display. Default: 12
// Example:
// fmtf(PI,12); // Returns: "3.14159265359"
// fmtf([PI,-16.75],12); // Returns: "[3.14159265359, -16.75]"
function fmtf(f,sig=12) =
assert(is_int(sig))
assert(sig>0)
is_list(f)? str("[",str_join(sep=", ", [for (g=f) fmtf(g,sig=sig)]),"]") :
f==0? "0" :
str(f)=="nan"? "nan" :
str(f)=="inf"? "inf" :
f<0? str("-",fmtf(-f,sig=sig)) :
assert(is_num(f))
let(
e = floor(log(f)),
mv = sig - e - 1
) mv == 0? fmti(floor(f + 0.5)) :
(e<-sig/2||mv<0)? str(fmtf(f*pow(10,-e),sig=sig),"e",e) :
let(
ff = f + pow(10,-mv)*0.5,
whole = floor(ff),
part = floor((ff-whole) * pow(10,mv))
)
str_join([
str(whole),
str_strip_trailing(
str_join([
".",
fmti(part, mindigits=mv)
]),
"0."
)
]);
// vim: noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap