Assign Regular Expression to variable

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Jeremy R asked Sep 4, '20 Phil BoBo edited Sep 8, '20

Assign Regular Expression to variable

Functions like string.match() and string.replace() can use regular expressions. According to the documentation, regular expressions are actually of the RegExp type. However, RegExp doesn't appear to be a valid type for a variable. i.e. the following code does not work

RegExp expression = /[0-9]/;

Is there any way to assign a regular expression to a variable? Or are all regular expressions required to be defined directly in the code?

The key reason I wanted to do this was to be able to dynamically construct a regular expression in code. Is there any way to do that in FlexScipt (e.g. constructing a string, then converting that string to a regular expression)?

Software Version:

FlexSim 18.2.3

flexsim 18.2.3 regex regexp regular expression

Answer 1 · 2020-09-04T15:33:14Z

Phil BoBo answered Sep 4, '20 Phil BoBo edited Sep 8, '20

You cannot dynamically construct a regular expression in FlexScript currently.

They can only be used as literals directly in the code where you are using them.

You cannot store them in a variable, return them from a function, or construct them from a string.

EDIT: If you build up the entire function call, then you can use executestring() to execute it. You can't execute just the regex part though, because you can't return a regex from a function. You must execute the entire function:

string text = "blue cars are really green.";
string findPattern = "/blue/gi";
if (uniform(0, 1) > 0.5)
    findPattern = "/green/gi";
string replaceWith = "red";

var function_with_regex = "eventdata.as(string).replace(" + findPattern + ", \"" + replaceWith + "\")";
return executestring(function_with_regex, 0, 0, text);

· 2

Jeremy R commented · Sep 06, 2020 at 11:14 PM

Alright, that's disappointing, but pretty much what I expected. Thanks for the direct answer.

0 ·

Phil BoBo ♦♦ Jeremy R commented · Sep 08, 2020 at 04:12 PM

@jeremy.r

You can wrap the syntax of that example into a user command so that your usage of it is cleaner:

return stringReplaceRegEx("blue cars are really green.", "/blue/gi", "red");

regex_usercommand.fsm

2 ·

regex-usercommand.png (103.9 KiB)

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