[ES6] Destructuring assignment need to accept iterables
https://bugs.webkit.org/show_bug.cgi?id=144111
Reviewed by Darin Adler.
Source/JavaScriptCore:
This patch makes that destructuring assignments to array binding patterns accept iterables.
Previously, it just access the indexed properties.
After this patch, it iterates the given value by using ES6 iterator protocol.
The iteration becomes different from the for-of case.
- Since there's no break/continue case, finally scope is not necessary.
- When the error is raised, the close status of the iterator becomes true. So IteratorClose is not called for that.
- Since the array binding patterns requires a limited count of iterations (if there is no rest(...rest) case), IteratorClose is called when the iteration does not consume the all values of the iterator.
- Since the array binding patterns requires a specified count of iterations, iterator's next call is skipped when iterator becomes closed.
- bytecompiler/BytecodeGenerator.cpp:
(JSC::BytecodeGenerator::emitIteratorClose):
- bytecompiler/BytecodeGenerator.h:
- bytecompiler/NodesCodegen.cpp:
(JSC::ArrayPatternNode::bindValue):
(JSC::ASTBuilder::finishArrayPattern):
- parser/Nodes.h:
- parser/Parser.cpp:
(JSC::Parser<LexerType>::parseDeconstructionPattern):
(JSC::SyntaxChecker::operatorStackPop):
- tests/stress/destructuring-assignment-accepts-iterables.js: Added.
(shouldBe):
(shouldThrow):
(.set shouldThrow):
LayoutTests:
From this patch, we use iterators for destructuring assignments to array binding patterns.
So test results become different.
- js/destructuring-assignment-expected.txt:
- js/parser-syntax-check-expected.txt:
- js/script-tests/destructuring-assignment.js:
