Rex Swain's PARSET Utility

This is very helpful when you want to write an XEDIT macro which allows additional arguments after a line target (like the PUT command does). Detecting the point in the argument where the target ends and the other arguments begin can be very tricky.

Example: Let's say you're writing FOO.REX and it's syntax is:

FOO target [filename [filetype [filemode]]]

You would code the beginning of FOO.REX like so:

/* FOO.REX */
 parse arg a              /* The entire argument        */

 i = parset(a)            /* Length of target           */
 t = left(a,i)            /* The target                 */
 r = substr(a,1+i)        /* Everything else            */
/* or: */
 i = 1 + parset(a)        /* 1 + Length of target       */
 parse var a t =(i) r     /* Same t and r as above      */

 say 'Target = "' || t || '"'
 say 'Remain = "' || r || '"'

If you execute:

FOO /x/&~,/,data txt

The following output will be produced:

Target = "/x/&~,/,"
Remain = "data txt"