ad06d73ace
The current two-level indexing scheme for function type parameters (depth and index) breaks down in the case of type substitution when the substituted type is a generic function type, since its internal type parameter types have been encoded assuming that the function type had nesting depth zero, but after substitution its nesting depth can be higher. Relative indexing schemes such as De Bruijn indices will also not work, since function type parameter types are constant types, and the constant infrastructure assumes that the same constant always has the same representation. This change introduces a flat indexing scheme where function type parameters are indexed using a single index which is independent of the context in which the type parameter type appears. To avoid collisions in the case of nested generic function types, every function type has a type parameter offset, which conceptually shifts the indexing range of its type parameters so it doesn't necessarily start at zero. Looking up a function type parameter in its environment thus involves searching outwards until a function type is found whose type parameter index range contains the index encoded in the function type parameter type. Change-Id: I544056d52711ff829b170f78a7274a93871825a4 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/272361 Reviewed-by: Joshua Litt <joshualitt@google.com> |
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benchmarks | ||
build | ||
docs | ||
pkg | ||
runtime | ||
samples | ||
sdk | ||
tests | ||
third_party | ||
tools | ||
utils | ||
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AUTHORS | ||
BUILD.gn | ||
CHANGELOG.md | ||
codereview.settings | ||
CONTRIBUTING.md | ||
DEPS | ||
LICENSE | ||
OWNERS | ||
PATENT_GRANT | ||
PRESUBMIT.py | ||
README.dart-sdk | ||
README.md | ||
sdk_args.gni | ||
SECURITY.md | ||
WATCHLISTS |
Dart
A client-optimized language for fast apps on any platform
Dart is:
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Optimized for UI: Develop with a programming language specialized around the needs of user interface creation.
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Productive: Make changes iteratively: use hot reload to see the result instantly in your running app.
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Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web.
Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:
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Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.
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Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).
License & patents
Dart is free and open source.
See LICENSE and PATENT_GRANT.
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