Arrow functions are parsed from ParseAssignmentExpression(). Handling the
parameter list is done by letting ParseConditionalExpression() parse a comma
separated list of identifiers, and it returns a tree of BinaryOperation nodes
with VariableProxy leaves, or a single VariableProxy if there is only one
parameter. When the arrow token "=>" is found, the VariableProxy nodes are
passed to ParseArrowFunctionLiteral(), which will then skip parsing the
paramaeter list. This avoids having to rewind when the arrow is found and
restart parsing the parameter list.
Note that the empty parameter list "()" is handled directly in
ParsePrimaryExpression(): after is has consumed the opening parenthesis,
if a closing parenthesis follows, then the only valid input is an arrow
function. In this case, ParsePrimaryExpression() directly calls
ParseArrowFunctionLiteral(), to avoid needing to return a sentinel value
to signal the empty parameter list. Because it will consume the body of
the arrow function, ParseAssignmentExpression() will not see the arrow
"=>" token as next, and return the already-parser expression.
The implementation is done in ParserBase, so it was needed to do some
additions to ParserBase, ParserTraits and PreParserTraits. Some of the
glue code can be removed later on when more more functionality is moved
to ParserBase.
Additionally, this adds a runtime flag "harmony_arrow_functions"
(disabled by default); enabling "harmony" will enable it as well.
BUG=v8:2700
LOG=N
R=marja@chromium.org
Review URL: https://codereview.chromium.org/383983002
Patch from Adrián Pérez de Castro <aperez@igalia.com>.
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22366 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Arrow functions are parsed from ParseAssignmentExpression(). Handling the
parameter list is done by letting ParseConditionalExpression() parse a comma
separated list of identifiers, and it returns a tree of BinaryOperation nodes
with VariableProxy leaves, or a single VariableProxy if there is only one
parameter. When the arrow token "=>" is found, the VariableProxy nodes are
passed to ParseArrowFunctionLiteral(), which will then skip parsing the
paramaeter list. This avoids having to rewind when the arrow is found and
restart parsing the parameter list.
Note that the empty parameter list "()" is handled directly in
ParsePrimaryExpression(): after is has consumed the opening parenthesis,
if a closing parenthesis follows, then the only valid input is an arrow
function. In this case, ParsePrimaryExpression() directly calls
ParseArrowFunctionLiteral(), to avoid needing to return a sentinel value
to signal the empty parameter list. Because it will consume the body of
the arrow function, ParseAssignmentExpression() will not see the arrow
"=>" token as next, and return the already-parser expression.
The implementation is done in ParserBase, so it was needed to do some
additions to ParserBase, ParserTraits and PreParserTraits. Some of the
glue code can be removed later on when more more functionality is moved
to ParserBase.
Additionally, this adds a runtime flag "harmony_arrow_functions"
(disabled by default); enabling "harmony" will enable it as well.
BUG=v8:2700
LOG=N
R=marja@chromium.org
Review URL: https://codereview.chromium.org/385553003
Patch from Adrián Pérez de Castro <aperez@igalia.com>.
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22320 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Arrow functions are parsed from ParseAssignmentExpression. Handling the
parameter list is done by letting ParseConditionalExpression() parse
a comma-separated list of identifiers, and it returns a tree of
BinaryOperation nodes with VariableProxy leaves, or a single
VariableProxy if there is only one parameter. When the arrow token "=>"
is found, the VariableProxy nodes are passed to ParseFunctionLiteral(),
which will then skip parsing the paramaeter list. This avoids having
to rewind when the arrow is found and restart parsing the parameter
list. Note that ParseExpression() expects parenthesized expressions
to not be empty, so checking for a closing parenthesis is added in
handling the empty parameter list "()" will accept a right-paren and
return an empty expression, which means that the parameter list is
empty.
Additionally, this adds the following machinery:
- A runtime flag "harmony_arrow_functions" (disabled by default).
Enabling "harmony" will enable it as well.
- An IsArrow bit in SharedFunctionInfo, and accessors for it.
- An IsArrow bit in FunctionLiteral, accessorts for it, and
a constructor parameter to set its value.
- In ParserBase: allow_arrow_functions() and set_allow_arrow_functions()
- A V8 native %FunctionIsArrow(), which is used to skip adding the
"function " prefix when getting the source code for an arrow
function.
R=marja@chromium.org
Review URL: https://codereview.chromium.org/160073006
Patch from Adrián Pérez de Castro <aperez@igalia.com>.
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22265 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When FLAG_pretenure_call_new is on, we emit mementos on new object creation
in full code, and consume the feedback in crankshaft. A key difference in the
generated code for stubs is the allocation of an additional type vector slot for the
CallNew AST node, which simplifies the CallConstructStub and CallFunctionStub
considerably.
Some performance tuning still needs to be addressed, therefore the flag is off at
this moment, though fully functional. The goal is to remove the flag as soon as
possible, which allows much code deletion (yay).
R=hpayer@chromium.org
Review URL: https://codereview.chromium.org/132963012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20076 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
It is only needed in (Pre)Parser::ParseExpressionOrLabelledStatement for not
recognizing parenthesized identifiers as labels and in
(Pre)Parser::ParseSourceElements for not recognizing a parenthesized string as
directive prologue.
Parser Expressions don't keep track of whether they're parenthesized, so
PreParser Expressions shouldn't either.
In addition, add helper funcs for checking if an Expression is identifier or a
given identifier. (PreParser Expressions can do this.)
BUG=3126
LOG=N
R=ulan@chromium.org
Review URL: https://codereview.chromium.org/150103004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19140 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
