Enable literal syntax for RegExp objects just like List and Map

[DartBot]

This issue was originally filed by [email protected]

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In Javascript, just like [] and {} do for arrays and objects, Dart features LIst and Map shorthand create syntax.

But for some reason, for Regular Expression objects, this syntax (in Javascript, Perl, Ruby - use of the '//' delimiters) is not enabled.

So instead of:

new RegExp(r'^(_+)(._)$')

would like to write;

/^(_+)(._)$/

[madsager]

Added Area-Language, Triaged labels.

[lrhn]

It's less important to have syntax for RegExps in Dart than in JavaScript due to Dart's raw strings.
The corresponding JavaScript constructor would be RegExp("^(*+)(.*)$"). Notice the extra backslash. Having explicit syntax means you can avoid duplicating the backslashes which are escapes in both string literals and regexp syntax.
In Dart, you can just do new RegExp(r"^(_+)(._)$") and keep the original regexp syntax.

From a parser writer's perspective, I can tell you that the JS RegExp syntax is ... special - it means that you can't separate tokenization from parsing, because you can't tell what, e.g., "/x/g" means without parsing. Is it a regexp literal, or are you writing "y/x/g" to divide by both x and g?

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Removed Type-Defect label.
Added Type-Enhancement label.

[DartBot]

This comment was originally written by [email protected]

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Isn't this a dupe of issue #289?

[DartBot]

This comment was originally written by [email protected]

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So what you're saying is that while the Dart parser can distinguish braces for Maps v. braces for code blocks, but is unable to perform like Javascript in distinguishing a literal regular expression v. math expression?

It's a code smell and a step backwards. Sorry, new RegExp(r'^(\\*+)(.\*)$'); is not as concise and clear as /^(_+)(._)$/.

[gbracha]

Added Duplicate label.
Marked as being merged into #289.