Function: filter_text

Function: filter_text

Usage

 filter_text(some_string, match: regular expression, in_context: regular expression)

Filter text by only keeping the parts of the input that match the regular expression.

If in_context is given, the context must also match the string where the match is represented as <match>.

When the filter_text is used many times with the same match or in_context values it is more efficient to declare these as default arguments:

 my_filter := filter_text@(match: "something")
 my_filter("input") # called many times

This way the regular expression is only compiled once.

Parameters

Parameter Type Description
input string String to replace in.
match regex Regular expression to match.
in_context regex (optional) Context to match

Examples

 filter_text(match: "a", "banana")  ==  "aaa"
 filter_text(match: ".", in_context:"a<match>", "banana")  ==  "nn"
 filter_text(match: "[xy]", "xyz")  ==  "xy"

 f := filter_text@(match: "xx+")
 f("xyzxxyyzz") == "xx"

See also

break_text Break text into parts each matching a regular expression.
replace Replace text matching a regular expression.