Extracting helper functions in generators

[jedwards1211]

I was looking into implementing Regex.Escape for JS/TS. Even though it's pretty simple (string.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&')) I think it would be better to write a regexEscape helper function at the top of the file and then call it.

I haven't noticed evidence that GenJs currently does this for anything else...I think a generic mechanism to extract helper functions would be useful in a lot of situations.

This would make the rest of the translation simple to write:

Write(regexEscapeMethodName + '(');
pattern.Accept(this, CiPriority.Statement);
Write(')');

The main challenges would be

• Extracting a function needs to automatically add something to the function name if it would conflict with the user's own identifiers
• Since generation relies on sequential Write calls there's not currently a way to go back and insert something at the top of the output

What do you think? If nothing else we could run all the code through a visitor to decide what to extract before writing anything.

[pfusik]

There's a mechanism for that. Search for GenJsMethod.

[jedwards1211]

Oh okay, great!