Better Matcher API and File Patterns Plan

Status: Project

Main proponents: YourNameHere

$/!\$ This is a speculative project and does not represent any firm decisions on future behavior.

Add a short summary of the idea here.

1. Goal

Short term: add non-recursive globs ?
Long term: extensible matcher API ?

2. Detailed description

2.1. Sprint Notes

Non-recursive globs (Rodrigo, spectral, Durham, :
    Issue is that * is sometimes recursive
    matcher API is a mess
    Should we re-write match.py or just add fileglob?
    Suggestion: add fileglob via a new, cleaner API, then migrate others over time
    Possible FB use case: pick parts of a tree to include and exclude (would add ordering dependency instead of excludes always trumping includes?)
    matcher API should be extensible
    matcher composition: anyof, allof, negate, per-file-type, etc.
    Inconsistencies in pattern behavior between hgignore, --include/--exclude, etc.
    FB: conversion between matchers and watchman expressions
    Proposal: wiki page, first group to have a use case proposes the initial API

2.2. Current Status

pattern type	root-ed	cwd-ed	any-of-path
wildcard	---	glob	relglob
regexp	re	---	relre
raw string	path	relpath	---

If rule is read in from file (e.g. .hgignore):

"glob" is treated as "relglob"
"re" is treated as "relre"

This is mentioned in "hg help patterns" and "hg help hgignore", but syntax name "relglob" and "relre" themselves aren't explained.

"end of name" matching is required:

for glob/relglob as PATTERN (e.g. argument in command line), but
not for glob/relglob as INCLUDES/EXCLUDES, or other pattern syntaxes

For example, file "foo/bar/baz" is:

not matched at: hg files glob:foo/bar
not matched at: hg files -I 'set:"glob:foo/bar"'
but matched at: hg files -I glob:foo/bar

This isn't mentioned in any help document :-<, and the latter seems to cause the issue mentioned in this patch series.

2.3. Proposal by foozy

How about introducing new systematic names like below to re-organize current complicated mapping between names and matching ? (and enable "end of name" matching by "-eon" suffix or so)

pattern type	root-ed	cwd-ed	any-of-path
wildcard	rootglob	cwdglob	anyglob
regexp	rootre	cwdre	anyre
raw string	rootpath	cwdpath	anypath

Of course, we should take care of backward compatibility of .hgignore or so (e.g. config knob to warn/abort for new syntax name in .hgignore).

2.4. Proposal by Rodrigo

Add rootglob: to get over the issue of -I/-X patterns.

https://patchwork.mercurial-scm.org/patch/17311/

3. Roadmap

4. See Also

http://d.hatena.ne.jp/flying-foozy/20140107/1389087728

CategoryDeveloper CategoryNewFeatures

FileNamePatternsPlan