/*
StrayNumToFt - Converts a string-array which just consists of numbers or simple math expressions to a function table

DESCRIPTION
Puts all numbers in Stray (which must not contain non-numerical elements) in a function table and returns its variable ift (which is produced by iftno, default=0) and the length of the elements written iftlen. (An empty string as input writes a function table of size=1 to avoid an error but returns 0 as length of elements written.) Simple binary math expressions using +, -, *, /, ^ and % are allowed, with just one parenthesis in total (see the examples below). 
Elements are defined by two seperators as ASCII coded characters: isep1 defaults to 32 (= space), isep2 defaults to 9 (= tab). If just one seperator is used, isep2 equals isep1.
Requires csound 5.15 or higher, and the UDOs StrayLen, StrExpr1 and StrExpr2


SYNTAX
ift, iftlen StrayNumToFt Stray [, iftno [, isep1 [, isep2]]]

INITIALIZATION
Stray - a string as array
iftno - like in an ftgen statement: if 0 (which is also the default) an automatic number is generated by Csound; if any positive number, this is then the number of the function table
isep1 - the first seperator (default=32: space)
isep2 - the second seperator (default=9: tab) 
ift - the number of the function table which has been created
iftlen - the length of the elements written to the function table (usually this equals the length of the function table; just an empty string as input will create a function table of size=1 but with iftlen=0)

CREDITS
joachim heintz april 2010 / sept 2011 / feb 2012 / dec 2012
*/

  opcode StrayNumToFt, ii, Sojj
  ;requires the UDOs StrayLen, StrExpr1 and StrExpr2
Stray, iftno, isepA, isepB xin
;;DEFINE THE SEPERATORS
isep1     =         (isepA == -1 ? 32 : isepA)
isep2     =         (isepA == -1 && isepB == -1 ? 9 : (isepB == -1 ? isep1 : isepB))
Sep1      sprintf   "%c", isep1
Sep2      sprintf   "%c", isep2
;;CREATE A FUNCTION TABLE
iftlen    StrayLen  Stray, isep1, isep2
 if iftlen == 0 then
          prints    "WARNING! StrayNumToFt got empty string as input. Function table with length=1 created, but iftlen=0 returned.\n"
iftl      =         1
 else
iftl      =         iftlen
 endif
ift       ftgen     iftno, 0, -iftl, -2, 0 
;;INITIALIZE SOME PARAMETERS
ilen      strlen    Stray
istartsel =         -1; startindex for searched element
iel       =         -1; number of element in Stray and ift
iwarleer  =         1; is this the start of a new element
indx      =         0 ;character index
inewel    =         0 ;new element to find
;;LOOP
 if ilen == 0 igoto end ;don't go into the loop if Stray is empty
loop:
Schar     strsub    Stray, indx, indx+1; this character
isep1p    strcmp    Schar, Sep1; returns 0 if Schar is sep1
isep2p    strcmp    Schar, Sep2; 0 if Schar is sep2
is_sep    =         (isep1p == 0 || isep2p == 0 ? 1 : 0) ;1 if Schar is a seperator
 ;END OF STRING AND NO SEPARATORS BEFORE?
 if indx == ilen && iwarleer == 0 then
Sel       strsub    Stray, istartsel, -1
inewel    =         1
 ;FIRST CHARACTER OF AN ELEMENT?
 elseif is_sep == 0 && iwarleer == 1 then
istartsel =         indx ;if so, set startindex
iwarleer  =         0 ;reset info about previous separator 
iel       =         iel+1 ;increment element count
 ;FIRST SEPERATOR AFTER AN ELEMENT?
 elseif iwarleer == 0 && is_sep == 1 then
Sel       strsub    Stray, istartsel, indx ;get element
inewel    =         1 ;tell about
iwarleer  =         1 ;reset info about previous separator
 endif
 ;WRITE THE ELEMENT TO THE TABLE
 if inewel == 1 then
inum      StrExpr2  Sel ;convert expression to number
          tabw_i    inum, iel, ift ;write to ift
 endif
inewel    =         0
          loop_le   indx, 1, ilen, loop 
end:
          xout      ift, iftlen
  endop