Templates for ARG, PULL, and PARSE

The PULL, ARG and PARSE instructions use a template to parse a string.

The simplest template is a list of variables where each of them is assigned one word from the string, except the last variable in the list which will contain the rest of the string.

PARSE VALUE "one two three four " WITH a b c
now a="one"; b="two"; c="three four"
PARSE VALUE "one two three four " WITH a b c d e
now a="one"; b="two"; c="three"; d="four" and e=""

A dot '.' can be in the place of one or more variables, it is used as a place-holder.

PARSE VALUE "one two three four " WITH a . . d
now a="one"; d="four"

A more complex parsing is to use patterns for triggering.

number	which specifies an absolute position in string
	1 - is the first character in string
=(name)	as a position may be a variable enclosed
	in parenthesis after an equal symbol
[+|-]number	signed numbers are used as a relative positioning

PARSE VALUE "one two three four " WITH 2 a 6 b
now a="ne t"; b="wo three four " pos=6;
PARSE VALUE "one two three four " WITH 2 a =(pos) b
now a="ne t"; b="wo three four " PARSE VALUE "one two three four " WITH 2 a +2 b
now a="ne"; b=" two three four "

string - may be used as a target position.

PARSE VALUE "marmita/bill/vivi' WITH a '/' b '/' c
now a="marmita"; b="bill"; c="vivi"

(name) - also as a target may be used a variable encolsed in parenthesis

t = "%%"
PARSE VALUE "aabbcc%%ddeeff%%gg%%" WITH . (t) middle (t) . now middle="ddeeff"

CALL MyProc 'Hi',3,4
EXIT
MyProc:
PARSE ARG first, second, third	/* now first="Hi" */
...	/* second=3 */
	/* third=4 */