BOSL2/strings.scad
2019-06-11 21:55:39 -04:00

200 lines
8.1 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, substr="") =
is_list(pos) ? substr(str, pos[0], pos[1]-pos[0]+1) :
len <= 0 || pos>=len(str) ? substr :
len == undef ? substr(str, pos, len(str)-pos, 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)
// Description:
// Converts a string fraction, two integers separated by a "/" character, to a floating point number.
// Arguments:
// str = string to convert
// 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(""); // Returns 0
// str_frac("3/0"); // Returns inf
// str_frac("0/0"); // Returns nan
function str_frac(str) =
str == undef ? undef :
let( num = str_split(str,"/"))
len(num)==1 ? str_int(num[0]) :
len(num)==2 ? str_int(num[0])/str_int(num[1]) :
(0/0);
// 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]);