dart-sdk/tools/spec_parser/Dart.g
Erik Ernst 30201181ce Update Dart.g to support extension types, not inline classes
Change-Id: I785eae3d32363db95a3cad00ee3c2c827a5ec9da
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/319400
Commit-Queue: Erik Ernst <eernst@google.com>
Reviewed-by: Lasse Nielsen <lrn@google.com>
2023-08-09 11:34:28 +00:00

2200 lines
45 KiB
Text

// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
// CHANGES:
//
// v0.36 Update syntax from `inline class` to `extension type`, including
// a special case of primary constructors.
//
// v0.35 Change named optional parameter syntax to require '=', that is,
// remove the support for ':' as in `void f({int i: 1})`.
//
// v0.34 Add support for inline classes.
//
// v0.33 This commit does not change the derived language at all. It just
// changes several rules to use the regexp-like grammar operators to simplify
// onParts, recordLiteralNoConst, functionTypeTails, and functionType.
//
// v0.32 Remove unused non-terminal `patterns`.
//
// v0.31 Inline `identifierNotFUNCTION` into `identifier`. Replace all
// other references with `identifier` to match the spec.
//
// v0.30 Add support for the class modifiers `sealed`, `final`, `base`,
// `interface`, and for `mixin class` declarations. Also add support for
// unnamed libraries (`library;`). Introduce `otherIdentifier` to help
// maintaining consistency when the grammar is modified to mention any words
// that weren't previously mentioned, yet are not reserved or built-in.
//
// v0.29 Add an alternative in the `primary` rule to enable method invocations
// of the form `super(...)` and `super<...>(...)`. This was added to the
// language specification in May 21, b26e7287c318c0112610fe8b7e175289792dfde2,
// but the corresponding update here wasn't done here at the time.
//
// v0.28 Add support for `new` in `enumEntry`, e.g., `enum E { x.new(); }`.
// Add `identifierOrNew` non-terminal to simplify the grammar.
//
// v0.27 Remove unused non-terminals; make handling of interpolation in URIs
// consistent with the language specification. Make `partDeclaration` a
// start symbol in addition to `libraryDefinition` (such that no special
// precautions are needed in order to parse a part file). Corrected spacing
// in several rules.
//
// v0.26 Add missing `metadata` in `partDeclaration`.
//
// v0.25 Update pattern rules following changes to the patterns feature
// specification since v0.24.
//
// v0.24 Change constant pattern rules to allow Symbols and negative numbers.
//
// v0.23 Change logical pattern rules to || and &&.
//
// v0.22 Change pattern rules, following updated feature specification.
//
// v0.21 Add support for patterns.
//
// v0.20 Adjust record syntax such that () is allowed (denoting the empty
// record type and the empty record value).
//
// v0.19 Add support for super parameters, named arguments everywhere, and
// records.
//
// v0.18 Add support for enhanced `enum` declarations.
//
// v0.17 (58d917e7573c359580ade43845004dbbc62220d5) Correct `uri` to allow
// multi-line strings (raw and non-raw).
//
// v0.16 (284695f1937c262523a9a11b9084213f889c83e0) Correct instance variable
// declaration syntax such that `covariant late final` is allowed.
//
// v0.15 (6facd6dfdafa2953e8523348220d3129ea884678) Add support for
// constructor tearoffs and explicitly instantiated function tearoffs and
// type literals.
//
// v0.14 (f65c20124edd9e04f7b3a6f014f40c16f51052f6) Correct `partHeader`
// to allow uri syntax in a `PART OF` directive.
//
// v0.13 (bb5cb79a2fd57d6a480b922bc650d5cd15948753) Introduce non-terminals
// `builtinIdentifier` and `reservedWord`; update `typeAlias` to enable
// non-function type aliases; add missing `metadata` to formal parameter
// declarations; correct `symbolLiteral` to allow `VOID`;
// v0.12 (82403371ac00ddf004be60fa7b705474d2864509) Cf. language issue #1341:
// correct `metadata`. Change `qualifiedName` such that it only includes the
// cases with a '.'; the remaining case is added where `qualifiedName` is used.
//
// v0.11 (67c703063d5b68c9e132edbaf34dfe375851f5a6) Corrections, mainly:
// `fieldFormalParameter` now allows `?` on the parameter type; cascade was
// reorganized in the spec, it is now reorganized similarly here; `?` was
// removed from argumentPart (null-aware invocation was never added).
//
// v0.10 (8ccdb9ae796d543e4ad8f339c847c02b09018d2d) Simplify grammar by making
// `constructorInvocation` an alternative in `primary`.
//
// v0.9 (f4d7951a88e1b738e22b768c3bc72bf1a1062365) Introduce abstract and
// external variables.
//
// v0.8 (a9ea9365ad8a3e3b59115bd889a55b6aa2c5a5fa) Change null-aware
// invocations of `operator []` and `operator []=` to not have a period.
//
// v0.7 (6826faf583f6a543b1a0e2e85bd6a8042607ce00) Introduce extension and
// mixin declarations. Revise rules about string literals and string
// interpolation. Reorganize "keywords" (built-in identifiers, reserved words,
// other words that are specified in the grammar and not parsed as IDENTIFIER)
// into explicitly marked groups. Change the cascade syntax to be
// compositional.
//
// v0.6 (a58052974ec2b4b334922c5227b043ed2b9c2cc5) Introduce syntax associated
// with null safety.
//
// v0.5 (56793b3d4714d4818d855a72074d5295489aef3f) Stop treating `ASYNC` as a
// conditional reserved word (only `AWAIT` and `YIELD` get this treatment).
//
// v0.4 Added support for 'unified collections' (spreads and control flow
// in collection literals).
//
// v0.3 Updated to use ANTLR v4 rather than antlr3.
//
// v0.2 Changed top level variable declarations to avoid redundant and
// misleading occurrence of (FINAL|CONST).
//
// v0.1 First version available in the SDK github repository. Covers the
// Dart language as specified in the language specification based on the
// many grammar rule snippets. That grammar was then adjusted to remove
// known issues (e.g., misplaced metadata) and to resolve ambiguities.
grammar Dart;
@parser::header{
import java.util.Stack;
}
@lexer::header{
import java.util.Stack;
}
@parser::members {
static String filePath = null;
static boolean errorHasOccurred = false;
/// Must be invoked before the first error is reported for a library.
/// Will print the name of the library and indicate that it has errors.
static void prepareForErrors() {
errorHasOccurred = true;
System.err.println("Syntax error in " + filePath + ":");
}
/// Parse library, return true if success, false if errors occurred.
public boolean parseLibrary(String filePath) throws RecognitionException {
this.filePath = filePath;
errorHasOccurred = false;
startSymbol();
return !errorHasOccurred;
}
// Enable the parser to treat AWAIT/YIELD as keywords in the body of an
// `async`, `async*`, or `sync*` function. Access via methods below.
private Stack<Boolean> asyncEtcAreKeywords = new Stack<Boolean>();
{ asyncEtcAreKeywords.push(false); }
// Use this to indicate that we are now entering an `async`, `async*`,
// or `sync*` function.
void startAsyncFunction() { asyncEtcAreKeywords.push(true); }
// Use this to indicate that we are now entering a function which is
// neither `async`, `async*`, nor `sync*`.
void startNonAsyncFunction() { asyncEtcAreKeywords.push(false); }
// Use this to indicate that we are now leaving any function.
void endFunction() { asyncEtcAreKeywords.pop(); }
// Whether we can recognize AWAIT/YIELD as an identifier/typeIdentifier.
boolean asyncEtcPredicate(int tokenId) {
if (tokenId == AWAIT || tokenId == YIELD) {
return !asyncEtcAreKeywords.peek();
}
return false;
}
}
@lexer::members{
public static final int BRACE_NORMAL = 1;
public static final int BRACE_SINGLE = 2;
public static final int BRACE_DOUBLE = 3;
public static final int BRACE_THREE_SINGLE = 4;
public static final int BRACE_THREE_DOUBLE = 5;
// Enable the parser to handle string interpolations via brace matching.
// The top of the `braceLevels` stack describes the most recent unmatched
// '{'. This is needed in order to enable/disable certain lexer rules.
//
// NORMAL: Most recent unmatched '{' was not string literal related.
// SINGLE: Most recent unmatched '{' was `'...${`.
// DOUBLE: Most recent unmatched '{' was `"...${`.
// THREE_SINGLE: Most recent unmatched '{' was `'''...${`.
// THREE_DOUBLE: Most recent unmatched '{' was `"""...${`.
//
// Access via functions below.
private Stack<Integer> braceLevels = new Stack<Integer>();
// Whether we are currently in a string literal context, and which one.
boolean currentBraceLevel(int braceLevel) {
if (braceLevels.empty()) return false;
return braceLevels.peek() == braceLevel;
}
// Use this to indicate that we are now entering a specific '{...}'.
// Call it after accepting the '{'.
void enterBrace() {
braceLevels.push(BRACE_NORMAL);
}
void enterBraceSingleQuote() {
braceLevels.push(BRACE_SINGLE);
}
void enterBraceDoubleQuote() {
braceLevels.push(BRACE_DOUBLE);
}
void enterBraceThreeSingleQuotes() {
braceLevels.push(BRACE_THREE_SINGLE);
}
void enterBraceThreeDoubleQuotes() {
braceLevels.push(BRACE_THREE_DOUBLE);
}
// Use this to indicate that we are now exiting a specific '{...}',
// no matter which kind. Call it before accepting the '}'.
void exitBrace() {
// We might raise a parse error here if the stack is empty, but the
// parsing rules should ensure that we get a parse error anyway, and
// it is not a big problem for the spec parser even if it misinterprets
// the brace structure of some programs with syntax errors.
if (!braceLevels.empty()) braceLevels.pop();
}
}
// ---------------------------------------- Grammar rules.
startSymbol
: libraryDefinition
| partDeclaration
;
libraryDefinition
: FEFF? SCRIPT_TAG?
libraryName?
importOrExport*
partDirective*
(metadata topLevelDefinition)*
EOF
;
topLevelDefinition
: classDeclaration
| mixinDeclaration
| extensionTypeDeclaration
| extensionDeclaration
| enumType
| typeAlias
| EXTERNAL functionSignature ';'
| EXTERNAL getterSignature ';'
| EXTERNAL setterSignature ';'
| EXTERNAL finalVarOrType identifierList ';'
| getterSignature functionBody
| setterSignature functionBody
| functionSignature functionBody
| (FINAL | CONST) type? staticFinalDeclarationList ';'
| LATE FINAL type? initializedIdentifierList ';'
| LATE? varOrType identifier ('=' expression)?
(',' initializedIdentifier)* ';'
;
declaredIdentifier
: COVARIANT? finalConstVarOrType identifier
;
finalConstVarOrType
: LATE? FINAL type?
| CONST type?
| LATE? varOrType
;
finalVarOrType
: FINAL type?
| varOrType
;
varOrType
: VAR
| type
;
initializedIdentifier
: identifier ('=' expression)?
;
initializedIdentifierList
: initializedIdentifier (',' initializedIdentifier)*
;
functionSignature
: type? identifier formalParameterPart
;
functionBody
: '=>' { startNonAsyncFunction(); } expression { endFunction(); } ';'
| { startNonAsyncFunction(); } block { endFunction(); }
| ASYNC '=>'
{ startAsyncFunction(); } expression { endFunction(); } ';'
| (ASYNC | ASYNC '*' | SYNC '*')
{ startAsyncFunction(); } block { endFunction(); }
;
block
: LBRACE statements RBRACE
;
formalParameterPart
: typeParameters? formalParameterList
;
formalParameterList
: '(' ')'
| '(' normalFormalParameters ','? ')'
| '(' normalFormalParameters ',' optionalOrNamedFormalParameters ')'
| '(' optionalOrNamedFormalParameters ')'
;
normalFormalParameters
: normalFormalParameter (',' normalFormalParameter)*
;
optionalOrNamedFormalParameters
: optionalPositionalFormalParameters
| namedFormalParameters
;
optionalPositionalFormalParameters
: '[' defaultFormalParameter (',' defaultFormalParameter)* ','? ']'
;
namedFormalParameters
: LBRACE defaultNamedParameter (',' defaultNamedParameter)* ','? RBRACE
;
normalFormalParameter
: metadata normalFormalParameterNoMetadata
;
normalFormalParameterNoMetadata
: functionFormalParameter
| fieldFormalParameter
| simpleFormalParameter
| superFormalParameter
;
// NB: It is an anomaly that a functionFormalParameter cannot be FINAL.
functionFormalParameter
: COVARIANT? type? identifier formalParameterPart '?'?
;
simpleFormalParameter
: declaredIdentifier
| COVARIANT? identifier
;
// NB: It is an anomaly that VAR can be a return type (`var this.x()`).
fieldFormalParameter
: finalConstVarOrType? THIS '.' identifier (formalParameterPart '?'?)?
;
superFormalParameter
: type? SUPER '.' identifier (formalParameterPart '?'?)?
;
defaultFormalParameter
: normalFormalParameter ('=' expression)?
;
defaultNamedParameter
: REQUIRED? normalFormalParameter ('=' expression)?
;
typeWithParameters
: typeIdentifier typeParameters?
;
classDeclaration
: (classModifiers | mixinClassModifiers)
CLASS typeWithParameters superclass? interfaces?
LBRACE (metadata classMemberDeclaration)* RBRACE
| classModifiers CLASS mixinApplicationClass
;
classModifiers
: SEALED
| ABSTRACT? (BASE | INTERFACE | FINAL)?
;
mixinClassModifiers
: ABSTRACT? BASE? MIXIN
;
superclass
: EXTENDS typeNotVoidNotFunction mixins?
| mixins
;
mixins
: WITH typeNotVoidNotFunctionList
;
interfaces
: IMPLEMENTS typeNotVoidNotFunctionList
;
classMemberDeclaration
: methodSignature functionBody
| declaration ';'
;
mixinApplicationClass
: typeWithParameters '=' mixinApplication ';'
;
mixinDeclaration
: mixinModifier? MIXIN typeIdentifier typeParameters?
(ON typeNotVoidNotFunctionList)? interfaces?
LBRACE (metadata mixinMemberDeclaration)* RBRACE
;
mixinModifier
: SEALED
| BASE
| INTERFACE
| FINAL
;
// TODO: We might want to make this more strict.
mixinMemberDeclaration
: classMemberDeclaration
;
extensionTypeDeclaration
: EXTENSION TYPE CONST? typeWithParameters
representationDeclaration
interfaces?
LBRACE (metadata extensionTypeMemberDeclaration)* RBRACE
;
representationDeclaration
: ('.' identifierOrNew)? '(' metadata type identifier ')'
;
// TODO: We might want to make this more strict.
extensionTypeMemberDeclaration
: classMemberDeclaration
;
extensionDeclaration
: EXTENSION identifier? typeParameters? ON type
LBRACE (metadata extensionMemberDefinition)* RBRACE
;
// TODO: We might want to make this more strict.
extensionMemberDefinition
: classMemberDeclaration
;
methodSignature
: constructorSignature initializers
| factoryConstructorSignature
| STATIC? functionSignature
| STATIC? getterSignature
| STATIC? setterSignature
| operatorSignature
| constructorSignature
;
declaration
: EXTERNAL factoryConstructorSignature
| EXTERNAL constantConstructorSignature
| EXTERNAL constructorSignature
| (EXTERNAL STATIC?)? getterSignature
| (EXTERNAL STATIC?)? setterSignature
| (EXTERNAL STATIC?)? functionSignature
| EXTERNAL (STATIC? finalVarOrType | COVARIANT varOrType) identifierList
| ABSTRACT (finalVarOrType | COVARIANT varOrType) identifierList
| EXTERNAL? operatorSignature
| STATIC (FINAL | CONST) type? staticFinalDeclarationList
| STATIC LATE FINAL type? initializedIdentifierList
| STATIC LATE? varOrType initializedIdentifierList
| COVARIANT LATE FINAL type? identifierList
| COVARIANT LATE? varOrType initializedIdentifierList
| LATE? (FINAL type? | varOrType) initializedIdentifierList
| redirectingFactoryConstructorSignature
| constantConstructorSignature (redirection | initializers)?
| constructorSignature (redirection | initializers)?
;
staticFinalDeclarationList
: staticFinalDeclaration (',' staticFinalDeclaration)*
;
staticFinalDeclaration
: identifier '=' expression
;
operatorSignature
: type? OPERATOR operator formalParameterList
;
operator
: '~'
| binaryOperator
| '[' ']'
| '[' ']' '='
;
binaryOperator
: multiplicativeOperator
| additiveOperator
| shiftOperator
| relationalOperator
| '=='
| bitwiseOperator
;
getterSignature
: type? GET identifier
;
setterSignature
: type? SET identifier formalParameterList
;
constructorSignature
: constructorName formalParameterList
;
constructorName
: typeIdentifier ('.' identifierOrNew)?
;
// TODO: Add this in the language specification, use it in grammar rules.
identifierOrNew
: identifier
| NEW
;
redirection
: ':' THIS ('.' identifierOrNew)? arguments
;
initializers
: ':' initializerListEntry (',' initializerListEntry)*
;
initializerListEntry
: SUPER arguments
| SUPER '.' identifierOrNew arguments
| fieldInitializer
| assertion
;
fieldInitializer
: (THIS '.')? identifier '=' initializerExpression
;
initializerExpression
: conditionalExpression
| cascade
;
factoryConstructorSignature
: CONST? FACTORY constructorName formalParameterList
;
redirectingFactoryConstructorSignature
: CONST? FACTORY constructorName formalParameterList '='
constructorDesignation
;
constantConstructorSignature
: CONST constructorName formalParameterList
;
mixinApplication
: typeNotVoidNotFunction mixins interfaces?
;
enumType
: ENUM typeIdentifier typeParameters? mixins? interfaces? LBRACE
enumEntry (',' enumEntry)* (',')?
(';' (metadata classMemberDeclaration)*)?
RBRACE
;
enumEntry
: metadata identifier argumentPart?
| metadata identifier typeArguments? '.' identifierOrNew arguments
;
typeParameter
: metadata typeIdentifier (EXTENDS typeNotVoid)?
;
typeParameters
: '<' typeParameter (',' typeParameter)* '>'
;
metadata
: ('@' metadatum)*
;
metadatum
: constructorDesignation arguments
| identifier
| qualifiedName
;
expression
: patternAssignment
| functionExpression
| throwExpression
| assignableExpression assignmentOperator expression
| conditionalExpression
| cascade
;
expressionWithoutCascade
: functionExpressionWithoutCascade
| throwExpressionWithoutCascade
| assignableExpression assignmentOperator expressionWithoutCascade
| conditionalExpression
;
expressionList
: expression (',' expression)*
;
primary
: thisExpression
| SUPER unconditionalAssignableSelector
| SUPER argumentPart
| functionPrimary
| literal
| identifier
| newExpression
| constObjectExpression
| constructorInvocation
| '(' expression ')'
| constructorTearoff
| switchExpression
;
constructorInvocation
: typeName typeArguments '.' NEW arguments
| typeName '.' NEW arguments
;
literal
: nullLiteral
| booleanLiteral
| numericLiteral
| stringLiteral
| symbolLiteral
| setOrMapLiteral
| listLiteral
| recordLiteral
;
nullLiteral
: NULL
;
numericLiteral
: NUMBER
| HEX_NUMBER
;
booleanLiteral
: TRUE
| FALSE
;
stringLiteral
: (multiLineString | singleLineString)+
;
setOrMapLiteral
: CONST? typeArguments? LBRACE elements? RBRACE
;
listLiteral
: CONST? typeArguments? '[' elements? ']'
;
recordLiteral
: CONST? recordLiteralNoConst
;
recordLiteralNoConst
: '(' ')'
| '(' expression ',' ')'
| '(' label expression ','? ')'
| '(' recordField (',' recordField)+ ','? ')'
;
recordField
: label? expression
;
elements
: element (',' element)* ','?
;
element
: expressionElement
| mapElement
| spreadElement
| ifElement
| forElement
;
expressionElement
: expression
;
mapElement
: expression ':' expression
;
spreadElement
: ('...' | '...?') expression
;
ifElement
: ifCondition element (ELSE element)?
;
forElement
: AWAIT? FOR '(' forLoopParts ')' element
;
constructorTearoff
: typeName typeArguments? '.' NEW
;
switchExpression
: SWITCH '(' expression ')'
LBRACE switchExpressionCase (',' switchExpressionCase)* ','? RBRACE
;
switchExpressionCase
: guardedPattern '=>' expression
;
throwExpression
: THROW expression
;
throwExpressionWithoutCascade
: THROW expressionWithoutCascade
;
functionExpression
: formalParameterPart functionExpressionBody
;
functionExpressionBody
: '=>' { startNonAsyncFunction(); } expression { endFunction(); }
| ASYNC '=>' { startAsyncFunction(); } expression { endFunction(); }
;
functionExpressionWithoutCascade
: formalParameterPart functionExpressionWithoutCascadeBody
;
functionExpressionWithoutCascadeBody
: '=>' { startNonAsyncFunction(); }
expressionWithoutCascade { endFunction(); }
| ASYNC '=>' { startAsyncFunction(); }
expressionWithoutCascade { endFunction(); }
;
functionPrimary
: formalParameterPart functionPrimaryBody
;
functionPrimaryBody
: { startNonAsyncFunction(); } block { endFunction(); }
| (ASYNC | ASYNC '*' | SYNC '*')
{ startAsyncFunction(); } block { endFunction(); }
;
thisExpression
: THIS
;
newExpression
: NEW constructorDesignation arguments
;
constObjectExpression
: CONST constructorDesignation arguments
;
arguments
: '(' (argumentList ','?)? ')'
;
argumentList
: argument (',' argument)*
;
argument
: label? expression
;
cascade
: cascade '..' cascadeSection
| conditionalExpression ('?..' | '..') cascadeSection
;
cascadeSection
: cascadeSelector cascadeSectionTail
;
cascadeSelector
: '[' expression ']'
| identifier
;
cascadeSectionTail
: cascadeAssignment
| selector* (assignableSelector cascadeAssignment)?
;
cascadeAssignment
: assignmentOperator expressionWithoutCascade
;
assignmentOperator
: '='
| compoundAssignmentOperator
;
compoundAssignmentOperator
: '*='
| '/='
| '~/='
| '%='
| '+='
| '-='
| '<<='
| '>' '>' '>' '='
| '>' '>' '='
| '&='
| '^='
| '|='
| '??='
;
conditionalExpression
: ifNullExpression
('?' expressionWithoutCascade ':' expressionWithoutCascade)?
;
ifNullExpression
: logicalOrExpression ('??' logicalOrExpression)*
;
logicalOrExpression
: logicalAndExpression ('||' logicalAndExpression)*
;
logicalAndExpression
: equalityExpression ('&&' equalityExpression)*
;
equalityExpression
: relationalExpression (equalityOperator relationalExpression)?
| SUPER equalityOperator relationalExpression
;
equalityOperator
: '=='
| '!='
;
relationalExpression
: bitwiseOrExpression
(typeTest | typeCast | relationalOperator bitwiseOrExpression)?
| SUPER relationalOperator bitwiseOrExpression
;
relationalOperator
: '>' '='
| '>'
| '<='
| '<'
;
bitwiseOrExpression
: bitwiseXorExpression ('|' bitwiseXorExpression)*
| SUPER ('|' bitwiseXorExpression)+
;
bitwiseXorExpression
: bitwiseAndExpression ('^' bitwiseAndExpression)*
| SUPER ('^' bitwiseAndExpression)+
;
bitwiseAndExpression
: shiftExpression ('&' shiftExpression)*
| SUPER ('&' shiftExpression)+
;
bitwiseOperator
: '&'
| '^'
| '|'
;
shiftExpression
: additiveExpression (shiftOperator additiveExpression)*
| SUPER (shiftOperator additiveExpression)+
;
shiftOperator
: '<<'
| '>' '>' '>'
| '>' '>'
;
additiveExpression
: multiplicativeExpression (additiveOperator multiplicativeExpression)*
| SUPER (additiveOperator multiplicativeExpression)+
;
additiveOperator
: '+'
| '-'
;
multiplicativeExpression
: unaryExpression (multiplicativeOperator unaryExpression)*
| SUPER (multiplicativeOperator unaryExpression)+
;
multiplicativeOperator
: '*'
| '/'
| '%'
| '~/'
;
unaryExpression
: prefixOperator unaryExpression
| awaitExpression
| postfixExpression
| (minusOperator | tildeOperator) SUPER
| incrementOperator assignableExpression
;
prefixOperator
: minusOperator
| negationOperator
| tildeOperator
;
minusOperator
: '-'
;
negationOperator
: '!'
;
tildeOperator
: '~'
;
awaitExpression
: AWAIT unaryExpression
;
postfixExpression
: assignableExpression postfixOperator
| primary selector*
;
postfixOperator
: incrementOperator
;
selector
: '!'
| assignableSelector
| argumentPart
| typeArguments
;
argumentPart
: typeArguments? arguments
;
incrementOperator
: '++'
| '--'
;
assignableExpression
: SUPER unconditionalAssignableSelector
| primary assignableSelectorPart
| identifier
;
assignableSelectorPart
: selector* assignableSelector
;
unconditionalAssignableSelector
: '[' expression ']'
| '.' identifier
;
assignableSelector
: unconditionalAssignableSelector
| '?.' identifier
| '?' '[' expression ']'
;
identifier
: IDENTIFIER
| builtInIdentifier
| otherIdentifier
| { asyncEtcPredicate(getCurrentToken().getType()) }? (AWAIT|YIELD)
;
qualifiedName
: typeIdentifier '.' identifierOrNew
| typeIdentifier '.' typeIdentifier '.' identifierOrNew
;
typeIdentifier
: IDENTIFIER
| DYNAMIC // Built-in identifier that can be used as a type.
| otherIdentifier // Occur in grammar rules, are not built-in.
| { asyncEtcPredicate(getCurrentToken().getType()) }? (AWAIT|YIELD)
;
typeTest
: isOperator typeNotVoid
;
isOperator
: IS '!'?
;
typeCast
: asOperator typeNotVoid
;
asOperator
: AS
;
pattern
: logicalOrPattern
;
logicalOrPattern
: logicalAndPattern ('||' logicalAndPattern)*
;
logicalAndPattern
: relationalPattern ('&&' relationalPattern)*
;
relationalPattern
: (equalityOperator | relationalOperator) bitwiseOrExpression
| unaryPattern
;
unaryPattern
: castPattern
| nullCheckPattern
| nullAssertPattern
| primaryPattern
;
primaryPattern
: constantPattern
| variablePattern
| parenthesizedPattern
| listPattern
| mapPattern
| recordPattern
| objectPattern
;
castPattern
: primaryPattern AS type
;
nullCheckPattern
: primaryPattern '?'
;
nullAssertPattern
: primaryPattern '!'
;
constantPattern
: booleanLiteral
| nullLiteral
| '-'? numericLiteral
| stringLiteral
| symbolLiteral
| identifier
| qualifiedName
| constObjectExpression
| CONST typeArguments? '[' elements? ']'
| CONST typeArguments? LBRACE elements? RBRACE
| CONST '(' expression ')'
;
variablePattern
: (VAR | FINAL | FINAL? type)? identifier
;
parenthesizedPattern
: '(' pattern ')'
;
listPattern
: typeArguments? '[' listPatternElements? ']'
;
listPatternElements
: listPatternElement (',' listPatternElement)* ','?
;
listPatternElement
: pattern
| restPattern
;
restPattern
: '...' pattern?
;
mapPattern
: typeArguments? LBRACE mapPatternEntries? RBRACE
;
mapPatternEntries
: mapPatternEntry (',' mapPatternEntry)* ','?
;
mapPatternEntry
: expression ':' pattern
| '...'
;
recordPattern
: '(' patternFields? ')'
;
patternFields
: patternField (',' patternField)* ','?
;
patternField
: (identifier? ':')? pattern
;
objectPattern
: typeName typeArguments? '(' patternFields? ')'
;
patternVariableDeclaration
: (FINAL | VAR) outerPattern '=' expression
;
outerPattern
: parenthesizedPattern
| listPattern
| mapPattern
| recordPattern
| objectPattern
;
patternAssignment
: outerPattern '=' expression
;
statements
: statement*
;
statement
: label* nonLabelledStatement
;
// Exception in the language specification: An expressionStatement cannot
// start with LBRACE. We force anything that starts with LBRACE to be a block,
// which will prevent an expressionStatement from starting with LBRACE, and
// which will not interfere with the recognition of any other case. If we
// add another statement which can start with LBRACE we must adjust this
// check.
nonLabelledStatement
: block
| localVariableDeclaration
| forStatement
| whileStatement
| doStatement
| switchStatement
| ifStatement
| rethrowStatement
| tryStatement
| breakStatement
| continueStatement
| returnStatement
| localFunctionDeclaration
| assertStatement
| yieldStatement
| yieldEachStatement
| expressionStatement
;
expressionStatement
: expression? ';'
;
localVariableDeclaration
: metadata initializedVariableDeclaration ';'
| metadata patternVariableDeclaration ';'
;
initializedVariableDeclaration
: declaredIdentifier ('=' expression)? (',' initializedIdentifier)*
;
localFunctionDeclaration
: metadata functionSignature functionBody
;
ifStatement
: ifCondition statement (ELSE statement)?
;
ifCondition
: IF '(' expression (CASE guardedPattern)? ')'
;
forStatement
: AWAIT? FOR '(' forLoopParts ')' statement
;
// TODO: Include `metadata` in the pattern form?
forLoopParts
: metadata declaredIdentifier IN expression
| metadata identifier IN expression
| forInitializerStatement expression? ';' expressionList?
| metadata (FINAL | VAR) outerPattern IN expression
;
// The localVariableDeclaration cannot be CONST, but that can
// be enforced in a later phase, and the grammar allows it.
forInitializerStatement
: localVariableDeclaration
| expression? ';'
;
whileStatement
: WHILE '(' expression ')' statement
;
doStatement
: DO statement WHILE '(' expression ')' ';'
;
switchStatement
: SWITCH '(' expression ')'
LBRACE switchStatementCase* switchStatementDefault? RBRACE
;
switchStatementCase
: label* CASE guardedPattern ':' statements
;
guardedPattern
: pattern (WHEN expression)?
;
switchStatementDefault
: label* DEFAULT ':' statements
;
rethrowStatement
: RETHROW ';'
;
tryStatement
: TRY block (onPart+ finallyPart? | finallyPart)
;
onPart
: catchPart block
| ON typeNotVoid catchPart? block
;
catchPart
: CATCH '(' identifier (',' identifier)? ')'
;
finallyPart
: FINALLY block
;
returnStatement
: RETURN expression? ';'
;
label
: identifier ':'
;
breakStatement
: BREAK identifier? ';'
;
continueStatement
: CONTINUE identifier? ';'
;
yieldStatement
: YIELD expression ';'
;
yieldEachStatement
: YIELD '*' expression ';'
;
assertStatement
: assertion ';'
;
assertion
: ASSERT '(' expression (',' expression)? ','? ')'
;
libraryName
: metadata LIBRARY dottedIdentifierList? ';'
;
dottedIdentifierList
: identifier ('.' identifier)*
;
importOrExport
: libraryImport
| libraryExport
;
libraryImport
: metadata importSpecification
;
importSpecification
: IMPORT configurableUri (DEFERRED? AS identifier)? combinator* ';'
;
combinator
: SHOW identifierList
| HIDE identifierList
;
identifierList
: identifier (',' identifier)*
;
libraryExport
: metadata EXPORT uri combinator* ';'
;
partDirective
: metadata PART uri ';'
;
partHeader
: metadata PART OF (dottedIdentifierList | uri)';'
;
partDeclaration
: FEFF? partHeader (metadata topLevelDefinition)* EOF
;
uri
: stringLiteral
;
configurableUri
: uri configurationUri*
;
configurationUri
: IF '(' uriTest ')' uri
;
uriTest
: dottedIdentifierList ('==' stringLiteral)?
;
type
: functionType '?'?
| typeNotFunction
;
typeNotVoid
: functionType '?'?
| recordType '?'?
| typeNotVoidNotFunction '?'?
;
typeNotFunction
: typeNotVoidNotFunction '?'?
| recordType '?'?
| VOID
;
typeNotVoidNotFunction
: typeName typeArguments?
| FUNCTION
;
typeName
: typeIdentifier ('.' typeIdentifier)?
;
typeArguments
: '<' typeList '>'
;
typeList
: type (',' type)*
;
recordType
: '(' ')'
| '(' recordTypeFields ',' recordTypeNamedFields ')'
| '(' recordTypeFields ','? ')'
| '(' recordTypeNamedFields ')'
;
recordTypeFields
: recordTypeField (',' recordTypeField)*
;
recordTypeField
: metadata type identifier?
;
recordTypeNamedFields
: LBRACE recordTypeNamedField (',' recordTypeNamedField)* ','? RBRACE
;
recordTypeNamedField
: metadata typedIdentifier
;
typeNotVoidNotFunctionList
: typeNotVoidNotFunction (',' typeNotVoidNotFunction)*
;
typeAlias
: TYPEDEF typeIdentifier typeParameters? '=' type ';'
| TYPEDEF functionTypeAlias
;
functionTypeAlias
: functionPrefix formalParameterPart ';'
;
functionPrefix
: type identifier
| identifier
;
functionTypeTail
: FUNCTION typeParameters? parameterTypeList
;
functionTypeTails
: (functionTypeTail '?'?)* functionTypeTail
;
functionType
: typeNotFunction? functionTypeTails
;
parameterTypeList
: '(' ')'
| '(' normalParameterTypes ',' optionalParameterTypes ')'
| '(' normalParameterTypes ','? ')'
| '(' optionalParameterTypes ')'
;
normalParameterTypes
: normalParameterType (',' normalParameterType)*
;
normalParameterType
: metadata typedIdentifier
| metadata type
;
optionalParameterTypes
: optionalPositionalParameterTypes
| namedParameterTypes
;
optionalPositionalParameterTypes
: '[' normalParameterTypes ','? ']'
;
namedParameterTypes
: LBRACE namedParameterType (',' namedParameterType)* ','? RBRACE
;
namedParameterType
: metadata REQUIRED? typedIdentifier
;
typedIdentifier
: type identifier
;
constructorDesignation
: typeIdentifier
| qualifiedName
| typeName typeArguments ('.' identifierOrNew)?
;
symbolLiteral
: '#' (operator | (identifier ('.' identifier)*) | VOID)
;
singleLineString
: RAW_SINGLE_LINE_STRING
| SINGLE_LINE_STRING_SQ_BEGIN_END
| SINGLE_LINE_STRING_SQ_BEGIN_MID expression
(SINGLE_LINE_STRING_SQ_MID_MID expression)*
SINGLE_LINE_STRING_SQ_MID_END
| SINGLE_LINE_STRING_DQ_BEGIN_END
| SINGLE_LINE_STRING_DQ_BEGIN_MID expression
(SINGLE_LINE_STRING_DQ_MID_MID expression)*
SINGLE_LINE_STRING_DQ_MID_END
;
multiLineString
: RAW_MULTI_LINE_STRING
| MULTI_LINE_STRING_SQ_BEGIN_END
| MULTI_LINE_STRING_SQ_BEGIN_MID expression
(MULTI_LINE_STRING_SQ_MID_MID expression)*
MULTI_LINE_STRING_SQ_MID_END
| MULTI_LINE_STRING_DQ_BEGIN_END
| MULTI_LINE_STRING_DQ_BEGIN_MID expression
(MULTI_LINE_STRING_DQ_MID_MID expression)*
MULTI_LINE_STRING_DQ_MID_END
;
reservedWord
: ASSERT
| BREAK
| CASE
| CATCH
| CLASS
| CONST
| CONTINUE
| DEFAULT
| DO
| ELSE
| ENUM
| EXTENDS
| FALSE
| FINAL
| FINALLY
| FOR
| IF
| IN
| IS
| NEW
| NULL
| RETHROW
| RETURN
| SUPER
| SWITCH
| THIS
| THROW
| TRUE
| TRY
| VAR
| VOID
| WHILE
| WITH
;
builtInIdentifier
: ABSTRACT
| AS
| COVARIANT
| DEFERRED
| DYNAMIC
| EXPORT
| EXTENSION
| EXTERNAL
| FACTORY
| FUNCTION
| GET
| IMPLEMENTS
| IMPORT
| INTERFACE
| LATE
| LIBRARY
| OPERATOR
| MIXIN
| PART
| REQUIRED
| SET
| STATIC
| TYPEDEF
;
otherIdentifier
: ASYNC
| BASE
| HIDE
| OF
| ON
| SEALED
| SHOW
| SYNC
| TYPE
| WHEN
;
// ---------------------------------------- Lexer rules.
fragment
LETTER
: 'a' .. 'z'
| 'A' .. 'Z'
;
fragment
DIGIT
: '0' .. '9'
;
fragment
EXPONENT
: ('e' | 'E') ('+' | '-')? DIGIT+
;
fragment
HEX_DIGIT
: ('a' | 'b' | 'c' | 'd' | 'e' | 'f')
| ('A' | 'B' | 'C' | 'D' | 'E' | 'F')
| DIGIT
;
// Reserved words (if updated, update `reservedWord` as well).
ASSERT
: 'assert'
;
BREAK
: 'break'
;
CASE
: 'case'
;
CATCH
: 'catch'
;
CLASS
: 'class'
;
CONST
: 'const'
;
CONTINUE
: 'continue'
;
DEFAULT
: 'default'
;
DO
: 'do'
;
ELSE
: 'else'
;
ENUM
: 'enum'
;
EXTENDS
: 'extends'
;
FALSE
: 'false'
;
FINAL
: 'final'
;
FINALLY
: 'finally'
;
FOR
: 'for'
;
IF
: 'if'
;
IN
: 'in'
;
IS
: 'is'
;
NEW
: 'new'
;
NULL
: 'null'
;
RETHROW
: 'rethrow'
;
RETURN
: 'return'
;
SUPER
: 'super'
;
SWITCH
: 'switch'
;
THIS
: 'this'
;
THROW
: 'throw'
;
TRUE
: 'true'
;
TRY
: 'try'
;
VAR
: 'var'
;
VOID
: 'void'
;
WHILE
: 'while'
;
WITH
: 'with'
;
// Built-in identifiers (if updated, update `builtInIdentifier` as well).
ABSTRACT
: 'abstract'
;
AS
: 'as'
;
COVARIANT
: 'covariant'
;
DEFERRED
: 'deferred'
;
DYNAMIC
: 'dynamic'
;
EXPORT
: 'export'
;
EXTENSION
: 'extension'
;
EXTERNAL
: 'external'
;
FACTORY
: 'factory'
;
FUNCTION
: 'Function'
;
GET
: 'get'
;
IMPLEMENTS
: 'implements'
;
IMPORT
: 'import'
;
INTERFACE
: 'interface'
;
LATE
: 'late'
;
LIBRARY
: 'library'
;
OPERATOR
: 'operator'
;
MIXIN
: 'mixin'
;
PART
: 'part'
;
REQUIRED
: 'required'
;
SET
: 'set'
;
STATIC
: 'static'
;
TYPEDEF
: 'typedef'
;
// "Contextual keywords".
AWAIT
: 'await'
;
YIELD
: 'yield'
;
// Other words used in the grammar (if updated, update `otherIdentifier`, too).
ASYNC
: 'async'
;
BASE
: 'base'
;
HIDE
: 'hide'
;
OF
: 'of'
;
ON
: 'on'
;
SEALED
: 'sealed'
;
SHOW
: 'show'
;
SYNC
: 'sync'
;
TYPE
: 'type'
;
WHEN
: 'when'
;
// Lexical tokens that are not words.
NUMBER
: DIGIT+ '.' DIGIT+ EXPONENT?
| DIGIT+ EXPONENT?
| '.' DIGIT+ EXPONENT?
;
HEX_NUMBER
: '0x' HEX_DIGIT+
| '0X' HEX_DIGIT+
;
RAW_SINGLE_LINE_STRING
: 'r' '\'' (~('\'' | '\r' | '\n'))* '\''
| 'r' '"' (~('"' | '\r' | '\n'))* '"'
;
RAW_MULTI_LINE_STRING
: 'r' '"""' (.)*? '"""'
| 'r' '\'\'\'' (.)*? '\'\'\''
;
fragment
SIMPLE_STRING_INTERPOLATION
: '$' IDENTIFIER_NO_DOLLAR
;
fragment
ESCAPE_SEQUENCE
: '\\n'
| '\\r'
| '\\b'
| '\\t'
| '\\v'
| '\\x' HEX_DIGIT HEX_DIGIT
| '\\u' HEX_DIGIT HEX_DIGIT HEX_DIGIT HEX_DIGIT
| '\\u{' HEX_DIGIT_SEQUENCE '}'
;
fragment
HEX_DIGIT_SEQUENCE
: HEX_DIGIT HEX_DIGIT? HEX_DIGIT?
HEX_DIGIT? HEX_DIGIT? HEX_DIGIT?
;
fragment
STRING_CONTENT_COMMON
: ~('\\' | '\'' | '"' | '$' | '\r' | '\n')
| ESCAPE_SEQUENCE
| '\\' ~('n' | 'r' | 'b' | 't' | 'v' | 'x' | 'u' | '\r' | '\n')
| SIMPLE_STRING_INTERPOLATION
;
fragment
STRING_CONTENT_SQ
: STRING_CONTENT_COMMON
| '"'
;
SINGLE_LINE_STRING_SQ_BEGIN_END
: '\'' STRING_CONTENT_SQ* '\''
;
SINGLE_LINE_STRING_SQ_BEGIN_MID
: '\'' STRING_CONTENT_SQ* '${' { enterBraceSingleQuote(); }
;
SINGLE_LINE_STRING_SQ_MID_MID
: { currentBraceLevel(BRACE_SINGLE) }?
{ exitBrace(); } '}' STRING_CONTENT_SQ* '${'
{ enterBraceSingleQuote(); }
;
SINGLE_LINE_STRING_SQ_MID_END
: { currentBraceLevel(BRACE_SINGLE) }?
{ exitBrace(); } '}' STRING_CONTENT_SQ* '\''
;
fragment
STRING_CONTENT_DQ
: STRING_CONTENT_COMMON
| '\''
;
SINGLE_LINE_STRING_DQ_BEGIN_END
: '"' STRING_CONTENT_DQ* '"'
;
SINGLE_LINE_STRING_DQ_BEGIN_MID
: '"' STRING_CONTENT_DQ* '${' { enterBraceDoubleQuote(); }
;
SINGLE_LINE_STRING_DQ_MID_MID
: { currentBraceLevel(BRACE_DOUBLE) }?
{ exitBrace(); } '}' STRING_CONTENT_DQ* '${'
{ enterBraceDoubleQuote(); }
;
SINGLE_LINE_STRING_DQ_MID_END
: { currentBraceLevel(BRACE_DOUBLE) }?
{ exitBrace(); } '}' STRING_CONTENT_DQ* '"'
;
fragment
QUOTES_SQ
:
| '\''
| '\'\''
;
// Read string contents, which may be almost anything, but stop when seeing
// '\'\'\'' and when seeing '${'. We do this by allowing all other
// possibilities including escapes, simple interpolation, and fewer than
// three '\''.
fragment
STRING_CONTENT_TSQ
: QUOTES_SQ
(STRING_CONTENT_COMMON | '"' | '\r' | '\n' | '\\\r' | '\\\n')
;
MULTI_LINE_STRING_SQ_BEGIN_END
: '\'\'\'' STRING_CONTENT_TSQ* '\'\'\''
;
MULTI_LINE_STRING_SQ_BEGIN_MID
: '\'\'\'' STRING_CONTENT_TSQ* QUOTES_SQ '${'
{ enterBraceThreeSingleQuotes(); }
;
MULTI_LINE_STRING_SQ_MID_MID
: { currentBraceLevel(BRACE_THREE_SINGLE) }?
{ exitBrace(); } '}' STRING_CONTENT_TSQ* QUOTES_SQ '${'
{ enterBraceThreeSingleQuotes(); }
;
MULTI_LINE_STRING_SQ_MID_END
: { currentBraceLevel(BRACE_THREE_SINGLE) }?
{ exitBrace(); } '}' STRING_CONTENT_TSQ* '\'\'\''
;
fragment
QUOTES_DQ
:
| '"'
| '""'
;
// Read string contents, which may be almost anything, but stop when seeing
// '"""' and when seeing '${'. We do this by allowing all other possibilities
// including escapes, simple interpolation, and fewer-than-three '"'.
fragment
STRING_CONTENT_TDQ
: QUOTES_DQ
(STRING_CONTENT_COMMON | '\'' | '\r' | '\n' | '\\\r' | '\\\n')
;
MULTI_LINE_STRING_DQ_BEGIN_END
: '"""' STRING_CONTENT_TDQ* '"""'
;
MULTI_LINE_STRING_DQ_BEGIN_MID
: '"""' STRING_CONTENT_TDQ* QUOTES_DQ '${'
{ enterBraceThreeDoubleQuotes(); }
;
MULTI_LINE_STRING_DQ_MID_MID
: { currentBraceLevel(BRACE_THREE_DOUBLE) }?
{ exitBrace(); } '}' STRING_CONTENT_TDQ* QUOTES_DQ '${'
{ enterBraceThreeDoubleQuotes(); }
;
MULTI_LINE_STRING_DQ_MID_END
: { currentBraceLevel(BRACE_THREE_DOUBLE) }?
{ exitBrace(); } '}' STRING_CONTENT_TDQ* '"""'
;
LBRACE
: '{' { enterBrace(); }
;
RBRACE
: { currentBraceLevel(BRACE_NORMAL) }? { exitBrace(); } '}'
;
fragment
IDENTIFIER_START_NO_DOLLAR
: LETTER
| '_'
;
fragment
IDENTIFIER_PART_NO_DOLLAR
: IDENTIFIER_START_NO_DOLLAR
| DIGIT
;
fragment
IDENTIFIER_NO_DOLLAR
: IDENTIFIER_START_NO_DOLLAR IDENTIFIER_PART_NO_DOLLAR*
;
fragment
IDENTIFIER_START
: IDENTIFIER_START_NO_DOLLAR
| '$'
;
fragment
IDENTIFIER_PART
: IDENTIFIER_START
| DIGIT
;
SCRIPT_TAG
: '#!' (~('\r' | '\n'))* NEWLINE
;
IDENTIFIER
: IDENTIFIER_START IDENTIFIER_PART*
;
SINGLE_LINE_COMMENT
: '//' (~('\r' | '\n'))* NEWLINE?
{ skip(); }
;
MULTI_LINE_COMMENT
: '/*' (MULTI_LINE_COMMENT | .)*? '*/'
{ skip(); }
;
fragment
NEWLINE
: ('\r' | '\n' | '\r\n')
;
FEFF
: '\uFEFF'
;
WS
: (' ' | '\t' | '\r' | '\n')+
{ skip(); }
;