

Task

   match a string against a regular expression
   substitute part of a string using a regular expression


#! Include the regex library
needs regex
 
#! The two test strings
" This is a string" is-data test.1
" Another string" is-data test.2
 
#! Create a new regex named 'expression' which tries
#! to match strings beginning with 'This'.
" ^This" regex: expression
 
#! An array to store the results of the match 
#! (Element 0 = starting offset, Element 1 = ending offset of match)
2 cells is-array match
 
#! Try both test strings against the expression. 
#! try-regex will return a flag.  -1 is TRUE, 0 is FALSE
expression test.1 2 match try-regex .
expression test.2 2 match try-regex .