`rex`

Regular expressions - match the first occurrence of a pattern in a string, find all non-overlapping matches, replace matches with a substitution string, test whether a pattern is present, and split a string on a pattern (empty strings removed). Thin wrappers over the host-injected __rex_* natives.

Load with: use rex

What this module does

rex provides ilusm access to the embedder's regex engine via four host-injected functions: __rex_mtc, __rex_all, __rex_rep, and __rex_spl. The pattern syntax depends on the host implementation (typically PCRE or ECMAScript regex).

Quick example

use rex

# First match
m = rexmt("\\d+", "order 42 has 7 items")
prn(m)  # "42"

# All matches
all = rexal("\\d+", "order 42 has 7 items")
prn(all)  # ["42", "7"]

# Replace
out = rexre("\\s+", "too   many   spaces", " ")
prn(out)  # "too many spaces"

# Has (test for presence)
prn(rexha("^\\d", "42abc"))  # tru

# Split on pattern
parts = rexsp("[,;\\s]+", "a, b; c d")
prn(parts)  # ["a", "b", "c", "d"]

Functions

Matching and search

rexmt(pattern, string)

Returns the first match of pattern in string, or nil if no match.

rexal(pattern, string)

Returns a list of all non-overlapping matches of pattern in string.

rexha(pattern, string)

Returns tru if pattern matches anywhere in string (coerced to string).

Replacement and splitting

rexre(pattern, string, replacement)

Replaces matches of pattern in string with replacement. Returns the new string.

rexsp(pattern, string)

Splits string on pattern. Empty strings in the result are filtered out.

Notes

Requires the host to inject __rex_mtc, __rex_all, __rex_rep, and __rex_spl. These are not available in all embedders.
Requires trl.