| commit | 92d95cdd8182e729bdc05a43f2e26842b6ae5fb1 | |
| author | Matt Schellhas <rms@fb.com> | |
| Wed, 27 Feb 2019 23:49:06 +0000 (27 15:49 -0800) | ||
| committer | Hhvm Bot <hhvm-bot@users.noreply.github.com> | |
| Wed, 27 Feb 2019 23:55:19 +0000 (27 15:55 -0800) | ||
| tree | 8b8d3df4127879e5e7e31168834e43129a4f81d7 | treesnapshot (tar.gz zip) |
| parent | 5763173f8f3dc1d8145d57ea82851f9859108477 | commitdiff |
AST changes to support optional type annotations for collection expressions
Summary:
The front end work to support optional explicit type annotations for stuff like `vec<string>[...]`.
The typechecking algorithm performs super-linearly when trying to infer the unification of things that are slightly different. Usually this isn't a problem because there are only a few things to unify. But sometimes there are more than a few things to unify... like what happens when a collection expression contains many subtypes of a common base. In some real world cases, this prevents the algorithm from finishing in a practical timeframe.
While people work to fix the super-linearity problem, allowing type hints for collection expressions should provide a work-around.
Reviewed By: oulgen
Differential Revision: D14093176
fbshipit-source-id: f81bad3ffca599df0b8133ed29581c3ee34c2b64
Summary:
The front end work to support optional explicit type annotations for stuff like `vec<string>[...]`.
The typechecking algorithm performs super-linearly when trying to infer the unification of things that are slightly different. Usually this isn't a problem because there are only a few things to unify. But sometimes there are more than a few things to unify... like what happens when a collection expression contains many subtypes of a common base. In some real world cases, this prevents the algorithm from finishing in a practical timeframe.
While people work to fix the super-linearity problem, allowing type hints for collection expressions should provide a work-around.
Reviewed By: oulgen
Differential Revision: D14093176
fbshipit-source-id: f81bad3ffca599df0b8133ed29581c3ee34c2b64
29 files changed: