regexp_outkeys

Extend the regexp function for old Matlab releases

regexp_outkeys documentation

Table of contents

• Description section:
• • Description
• Matlab/Octave section:
• • Syntax
• • Output arguments
• • Input arguments
• • Examples
• • Compatibility, version info, and licence

Description

This function extends the regexp function for old Matlab releases.
On older versions of Matlab the regexp function did not allow you to specify the output keys. This function has an implementation of the split, match, and tokens output keys, so they can be used on any version of Matlab or GNU Octave.

Note that the builtin regexp function is still used, so any limitation and bugs still apply. As an example; the lookaround assertions ((?<=test)expr etc) were introduced in v7 (R14) and are therefore not supported in this function either on v6.5.

Matlab/Octave

Syntax

out = regexp_outkeys(str,expression,outkey);
[out1,...,outN] = regexp_outkeys(str,expression,outkey1,...,outkeyN);
[___,startIndex] = regexp_outkeys(___);
[___,startIndex,endIndex] = regexp_outkeys(___);

Output arguments

Argument	Description
out	The result specified by the outkey: 'start': numeric array with the starting indices of the matches. 'end': numeric array with the ending indices of the matches. 'match': cellstr with the matches. 'split': cellstr with the non-matches. 'tokens': nested cellstr with the matched tokens.
startIndex	Same result as 'start' outkey.
endIndex	Same result as 'end' outkey.

Input arguments

Argument	Description
str	A char array containing the text to be searched.
expression	Regular expression. See the documentation for regexp for more explanation.
outkey	One of the supported outkeys: 'match', 'split', 'tokens', 'start', and 'end'. Duplicates are allowed.

Examples

A few examples of valid syntax options:

str = 'lorem1 ipsum1.2 dolor3 sit amet 99 ';
words = regexp_outkeys(str,' ','split')
numbers = regexp_outkeys(str,'[0-9.]*','match')
RawTokens = regexp_outkeys(str,'([a-z]+)[0-9]','tokens');
words_with_number = horzcat(RawTokens{:})
[white,end1,start,end2] = regexp_outkeys(str,' ','match','end')

Compatibility, version info, and licence

Compatibility considerations:

• Only the 'match', 'split', 'tokens', 'start', and 'end' options are supported. The additional options provided by regexp are also not implemented.
• Cell array input is not supported.

Test suite result	Windows	Linux	MacOS
Matlab R2022b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2022a	W11 : Pass
Matlab R2021b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2021a	W11 : Pass
Matlab R2020b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2020a	W11 : Pass
Matlab R2019b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2019a	W11 : Pass
Matlab R2018a	W11 : Pass	ubuntu_22.04 : Pass
Matlab R2017b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2016b	W11 : Pass	ubuntu_22.04 : Pass	Monterey : Pass
Matlab R2015a	W11 : Pass	ubuntu_22.04 : Pass
Matlab R2013b	W11 : Pass
Matlab R2007b	W11 : Pass
Matlab 6.5 (R13)	W11 : Pass
Octave 8.2.0	W11 : Pass
Octave 7.2.0	W11 : Pass
Octave 6.2.0	W11 : Pass	ubuntu_22.04 : Pass	Catalina : Pass
Octave 5.2.0	W11 : Pass
Octave 4.4.1	W11 : Pass		Catalina : Pass

Version: 2.0.0.1
Date:    2023-09-12
Author:  H.J. Wisselink
Licence: CC by-nc-sa 4.0 ( https://creativecommons.org/licenses/by-nc-sa/4.0 )
Email = 'h_j_wisselink*alumnus_utwente_nl';
Real_email = regexprep(Email,{'*','_'},{'@','.'})

Test suite

The tester is included so you can test if your own modifications would introduce any bugs. These tests form the basis for the compatibility table above. Note that functions may be different between the tester version and the normal function. Make sure to apply any modifications to both.