Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

feat: named capture groups and reference #66

Merged
merged 12 commits into from
Apr 3, 2024
Merged

Conversation

mdjastrzebski
Copy link
Member

@mdjastrzebski mdjastrzebski commented Mar 1, 2024

Summary

  1. capture(...) generates a Capturing Group ((...) in regex syntax). When calling String.match() or Regex.exec(), the result will be Array-like object. At index 0 it will hold whole matched regex, at indexes 1 and later it will hold values captured by consecutive capturing groups in the regex.

  2. capture(..., { name: 'aaa' }) generates a Named Capturing Group ((?<aaa>...) in regex). It results are also available on the match() result at specified indexes like regular Capturing Group. In addition to that, match result will also expose matched results by name, under result.group.aaa, etc. for each Named Capturing Group in the regex.

  3. Captured value can also be used during matching using Backreferences. Backreference can either refer to Capuring Group order (\1, \2, etc) or name (\k<aaa>, etc). In TS Regex Builder to use backreference we need to do following:

// Define reference named "quote"
const quote = reference('quote');

const regex = buildRegExp([
  // make capture use name "quote" by giving it a reference (
  capture(anyOf(`'"`), { name: quoteRef }), // => (?<quote>['"])

  // some other patterns (not important)
  zeroOrMore(word),

  // reference back the value captured in the "quote" reference by putting reference here
  quoteRef, // => \k<quote>
]);

Alternatives

Base idea:

// Named capture => (?<aaa>...)
capture(..., { name: 'aaa' });

// Named capture + backreference => (?<aaa>...) + \k<aaa>
const someRef = reference('some');
capture(..., { name: someRef });

Alternative 1: separete name and ref options:

// Named capture
capture(..., { name: 'aaa' })

// Named capture + backreference
const someRef = reference('some');
capture(..., { ref: someRef })

Alternative 2: explicitly define namedCapture:

// Named capture
namedCapture("aaa", [...]);

// Named capture + backreference
const someRef = namedReference("aaa");
namedCapture(someRef, [...]);

Test plan

@mdjastrzebski mdjastrzebski changed the title Feat/named reference feat: named captured groups and reference Mar 1, 2024
@codecov-commenter
Copy link

codecov-commenter commented Mar 4, 2024

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (65022ee) to head (6525391).

Additional details and impacted files
@@            Coverage Diff            @@
##              main       #66   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           16        16           
  Lines          183       190    +7     
  Branches        41        42    +1     
=========================================
+ Hits           183       190    +7     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

@mdjastrzebski
Copy link
Member Author

CC: @PaulPhilp

@mdjastrzebski mdjastrzebski force-pushed the feat/named-reference branch 2 times, most recently from 9bb2ea1 to 0ac8420 Compare March 28, 2024 12:07
@mdjastrzebski mdjastrzebski changed the title feat: named captured groups and reference feat: named capture groups and reference Mar 28, 2024
wip

chore: more tests

feat: improved refs

refactor: merge name and ref

refactor: self code review

refactor: tweaks

refactor: rename reference to ref

feat: example with html tags

chore: self code review
@mdjastrzebski
Copy link
Member Author

Merging this PR in a more restrictive syntax, capture(..., { name: 'groupName' }) and ref('groupName').

@mdjastrzebski mdjastrzebski merged commit 57f7265 into main Apr 3, 2024
4 checks passed
@mdjastrzebski mdjastrzebski deleted the feat/named-reference branch April 3, 2024 14:59
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

None yet

2 participants