To use this file copy and paste this:    // #URL-lib "http://pin1.org/forthlib/flb/General/strings.flb"   into BV Terminal 3 or here to download.

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *  
// A collection of useful words for dealing wth Forth strings
// a forth string is a series of consecutive bytes terminated 
// with a 0
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *  


// HISTORY:
// Dec 2008 Added strcopy$


// REQUIRES:
// does not depend on any other files.


// CONSTANTS:
// none defined but words in the file use local variables.

Full Contents of File

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
// A collection of useful words for dealing wth Forth strings
// a forth string is a series of consecutive bytes terminated
// with a 0
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

// HISTORY:
// Dec 2008 Added strcopy$

// REQUIRES:
// does not depend on any other files.

// CONSTANTS:
// none defined but words in the file use local variables.

// mid string function, given a string address str
// and an offset into it, it will produce another string form
// it, e.g.
// str="Hello fred"
// str 2 3 mid$, will produce
// "llo"
// Limitations: the local variable used is only transitory and so
// the address must be used imediately afer this call. It is limited
// to 80 characters
: mid$ { str offset len --- address }  
v$:  b  81
// error checking if required
// num 80 > abort" Max 80 Chars on mid$"
        offset  len  +    str  length  >  abort"  Mid$  outside  limits"
        str  offset  +  %@  b  len  // addr1, addr2, number -- for move
        move                                    // move form str to b
        0  %@  b  len  +  c!              // add terminating 0
        %@  b                                // return eith address
;

// copies one string to another and terminates when the
// first string has 0 or the max is reached.
: strcopy$ { str1 str2 max-len -- }
        max-len  for               
                i  str1  +  c@ 
                dup  0=  if  drop  unloop  escape  then
                i  str2  +  c!
        next
;               

// add two strings together and returns the address of the
// concatenated string
// limitations: uses local address so this must be used imediately
// sting length limited to 80 charatcres
: add$ { str1 str2 ---- addr }
v$:  buff  162          // buffer space for both strings
int:  len
        str1  length  =>  len    // lenggth of sting1 less terminationg 0
        str1  %@  buff  len  move  // buf=str1 less terminator
        str2  %@  buff  len  +  str2  length  1+  // include 0 terminator
        move
        %@  buff             
;

// Gets a number from an ASCII string where str is the address of the string
// offset is the diatnce into the string strating at 0
// len is the number of characters 2=byte 4=16bit word etc.
: hl-number { str offset len --- number|abort }    
      str  offset  len  mid$        // get substring
      s"  &"  swap  add$                // add & to front of string
      ?number    -1  <>  abort"  number  expected"
;

// returns the postion along the string of the delimiting char
// string is the string address
// start start along string
// ch = delimiting character
// returns 0 if char not found otherwise postion char found
// EXAMPLE string = fred bob" andy, start = 0 ch = "
// this will return 8
: instr$    { string start ch --- count }
int:  count

        begin
                start  string  +  count  +
                c@    dup  ch  <>  swap  0  <>  and  // ch or terminator
        while
                1  +>  count
        repeat
        start  string  +  count  +  c@
        0=  if  0  else  count  then
;

// extracts a string from an address delimited by char
// NOTE max set at 80
// ch = delimiting character
// address input is string to extarct from
// address output points to a local containing extracted string
// count size of extratced string - for calculating nect address
// returns 0 when no more characters
// returns pointing to a local address
: tab    { ch address --- address count }
v$:  buf  80
int:  count

        80  address  +  address
        do
                i  c@  dup  ch  =  swap  0  =  or  // ch or 0 termina
                if
                        0  %@  buf  count  +  c!  // add sting teminator
                        %@  buf    count          // leave with address & count
                        leave
                else
                        i  c@
                        %@  buf  count  +  c!  // store
                        1  +>  count
                then
        loop
;