dart/ast/ast library

Defines the AST model. The AST (Abstract Syntax Tree) model describes the syntactic (as opposed to semantic) structure of Dart code. The semantic structure of the code is modeled by the element model.

An AST consists of nodes (instances of a subclass of AstNode). The nodes are organized in a tree structure in which the children of a node are the smaller syntactic units from which the node is composed. For example, a binary expression consists of two sub-expressions (the operands) and an operator. The two expressions are represented as nodes. The operator is not represented as a node.

The AST is constructed by the parser based on the sequence of tokens produced by the scanner. Most nodes provide direct access to the tokens used to build the node. For example, the token for the operator in a binary expression can be accessed from the node representing the binary expression.

While any node can theoretically be the root of an AST structure, almost all of the AST structures known to the analyzer have a CompilationUnit as the root of the structure. A compilation unit represents all of the Dart code in a single file.

An AST can be either unresolved or resolved. When an AST is unresolved certain properties will not have been computed and the accessors for those properties will return null. The documentation for those getters should describe that this is a possibility.

When an AST is resolved, the identifiers in the AST will be associated with the elements that they refer to and every expression in the AST will have a type associated with it.

Classes

AdjacentStrings: Two or more string literals that are implicitly concatenated because of being adjacent (separated only by whitespace).
AnnotatedNode: An AST node that can be annotated with both a documentation comment and a list of annotations.
Annotation: An annotation that can be associated with an AST node.
ArgumentList: A list of arguments in the invocation of an executable element (that is, a function, method, or constructor).
AsExpression: An as expression.
AssertInitializer: An assert in the initializer list of a constructor.
Assertion: An assertion, either in a block or in the initializer list of a constructor.
AssertStatement: An assert statement.
AssignedVariablePattern: A variable pattern in PatternAssignment.
AssignmentExpression: An assignment expression.
AstNode: A node in the AST structure for a Dart program.
AstVisitor<R>: An object that can be used to visit an AST structure.
AugmentationImportDirective: An augmentation import directive.
AwaitExpression: An await expression.
BinaryExpression: A binary (infix) expression.
Block: A sequence of statements.
BlockFunctionBody: A function body that consists of a block of statements.
BooleanLiteral: A boolean literal expression.
BreakStatement: A break statement.
CascadeExpression: A sequence of cascaded expressions: expressions that share a common target.
CaseClause: The case clause that can optionally appear in an if statement.
CastPattern: A cast pattern.
CatchClause: A catch clause within a try statement.
CatchClauseParameter: The 'exception' or 'stackTrace' parameter in CatchClause.
ClassAugmentationDeclaration: The declaration of a class augmentation.
ClassDeclaration: The declaration of a class.
ClassMember: A node that declares a name within the scope of a class declarations.
ClassOrAugmentationDeclaration: Shared interface between ClassDeclaration and ClassAugmentationDeclaration.
ClassTypeAlias: A class type alias.
CollectionElement: An element in a list, map or set literal.
Combinator: A combinator associated with an import or export directive.
Comment: A comment within the source code.
CommentReferableExpression: An interface for an Expression which can make up a CommentReference.
CommentReference: A reference to a Dart element that is found within a documentation comment.
CompilationUnit: A compilation unit.
CompilationUnitMember: A node that declares one or more names within the scope of a compilation unit.
CompoundAssignmentExpression: A potentially compound assignment.
ConditionalExpression: A conditional expression.
Configuration: A configuration in either an import or export directive.
ConstantPattern: A constant expression being used as a pattern.
ConstructorDeclaration: A constructor declaration.
ConstructorFieldInitializer: The initialization of a field within a constructor's initialization list.
ConstructorInitializer: A node that can occur in the initializer list of a constructor declaration.
ConstructorName: The name of a constructor.
ConstructorReference: An expression representing a reference to a constructor, e.g. the expression List.filled in var x = List.filled;.
ConstructorReferenceNode: An AST node that makes reference to a constructor.
ConstructorSelector: The name of a constructor being invoked.
ContinueStatement: A continue statement.
DartPattern: A pattern.
Declaration: A node that represents the declaration of one or more names.
DeclaredIdentifier: The declaration of a single identifier.
DeclaredVariablePattern: A variable pattern that declares a variable.
DefaultFormalParameter: A formal parameter with a default value.
Directive: A node that represents a directive.
DoStatement: A do statement.
DottedName: A dotted name, used in a configuration within an import or export directive.
DoubleLiteral: A floating point literal expression.
EmptyFunctionBody: An empty function body, which can only appear in constructors or abstract methods.
EmptyStatement: An empty statement.
EnumConstantArguments: The arguments part of an enum constant.
EnumConstantDeclaration: The declaration of an enum constant.
EnumDeclaration: The declaration of an enumeration.
ExportDirective: An export directive.
Expression: A node that represents an expression.
ExpressionFunctionBody: A function body consisting of a single expression.
ExpressionStatement: An expression used as a statement.
ExtendsClause: The "extends" clause in a class declaration.
ExtensionDeclaration: The declaration of an extension of a type.
ExtensionOverride: An override to force resolution to choose a member from a specific extension.
FieldDeclaration: The declaration of one or more fields of the same type.
FieldFormalParameter: A field formal parameter.
ForEachParts: The parts of a for-each loop that control the iteration.
ForEachPartsWithDeclaration: The parts of a for-each loop that control the iteration when the loop variable is declared as part of the for loop.
ForEachPartsWithIdentifier: The parts of a for-each loop that control the iteration when the loop variable is declared outside of the for loop.
ForEachPartsWithPattern: A for-loop part with a pattern.
ForElement: The basic structure of a for element.
ForLoopParts: The parts of a for or for-each loop that control the iteration.
FormalParameter: A node representing a parameter to a function.
FormalParameterList: The formal parameter list of a method declaration, function declaration, or function type alias.
ForParts: The parts of a for loop that control the iteration.
ForPartsWithDeclarations: The parts of a for loop that control the iteration when there are one or more variable declarations as part of the for loop.
ForPartsWithExpression: The parts of a for loop that control the iteration when there are no variable declarations as part of the for loop.
ForPartsWithPattern: The parts of a for loop that control the iteration when there is a pattern declaration as part of the for loop.
ForStatement: A for or for-each statement.
FunctionBody: A node representing the body of a function or method.
FunctionDeclaration: A function declaration.
FunctionDeclarationStatement: A FunctionDeclaration used as a statement.
FunctionExpression: A function expression.
FunctionExpressionInvocation: The invocation of a function resulting from evaluating an expression.
FunctionReference: An expression representing a reference to a function, possibly with type arguments applied to it, e.g. the expression print in var x = print;.
FunctionTypeAlias: A function type alias.
FunctionTypedFormalParameter: A function-typed formal parameter.
GenericFunctionType: An anonymous function type.
GenericTypeAlias: A generic type alias.
GuardedPattern: The pattern with an optional WhenClause.
HideCombinator: A combinator that restricts the names being imported to those that are not in a given list.
Identifier: A node that represents an identifier.
IfElement: The basic structure of an if element.
IfStatement: An if statement.
ImplementsClause: The "implements" clause in an class declaration.
ImplicitCallReference: An expression representing an implicit 'call' method reference.
ImportDirective: An import directive.
ImportPrefixReference: Reference to an import prefix name.
IndexExpression: An index expression.
InstanceCreationExpression: An instance creation expression.
IntegerLiteral: An integer literal expression.
InterpolationElement: A node within a StringInterpolation.
InterpolationExpression: An expression embedded in a string interpolation.
InterpolationString: A non-empty substring of an interpolated string.
InvocationExpression: The invocation of a function or method; either a FunctionExpressionInvocation or a MethodInvocation.
IsExpression: An is expression.
Label: A label on either a LabeledStatement or a NamedExpression.
LabeledStatement: A statement that has a label associated with them.
LibraryAugmentationDirective: A library augmentation directive.
LibraryDirective: A library directive.
LibraryIdentifier: The identifier for a library.
ListLiteral: A list literal.
ListPattern: A list pattern.
ListPatternElement: An element of a list pattern.
Literal: A node that represents a literal expression.
LogicalAndPattern: A logical-and pattern.
LogicalOrPattern: A logical-or pattern.
MapLiteralEntry: A single key/value pair in a map literal.
MapPattern: A map pattern.
MapPatternElement: An element of a map pattern.
MapPatternEntry: An entry in a map pattern.
MethodDeclaration: A method declaration.
MethodInvocation: The invocation of either a function or a method.
MethodReferenceExpression: An expression that implicitly makes reference to a method.
MixinAugmentationDeclaration: The declaration of a mixin augmentation.
MixinDeclaration: The declaration of a mixin.
MixinOrAugmentationDeclaration: Shared interface between MixinDeclaration and MixinAugmentationDeclaration.
NamedCompilationUnitMember: A node that declares a single name within the scope of a compilation unit.
NamedExpression: An expression that has a name associated with it. They are used in method invocations when there are named parameters.
NamedType: A named type, which can optionally include type arguments.
NamespaceDirective: A node that represents a directive that impacts the namespace of a library.
NativeClause: The "native" clause in an class declaration.
NativeFunctionBody: A function body that consists of a native keyword followed by a string literal.
NodeList<E extends AstNode>: A list of AST nodes that have a common parent.
NormalFormalParameter: A formal parameter that is required (is not optional).
NullAssertPattern: A null-assert pattern.
NullCheckPattern: A null-check pattern.
NullLiteral: A null literal expression.
NullShortableExpression: Abstract interface for expressions that may participate in null-shorting.
ObjectPattern: An object pattern.
OnClause: The "on" clause in a mixin declaration.
ParenthesizedExpression: A parenthesized expression.
ParenthesizedPattern: A parenthesized pattern.
PartDirective: A part directive.
PartOfDirective: A part-of directive.
PatternAssignment: A pattern assignment.
PatternField: A field in an object or record pattern.
PatternFieldName: A field name in an object or record pattern field.
PatternVariableDeclaration: A pattern variable declaration.
PatternVariableDeclarationStatement: A pattern variable declaration statement.
PostfixExpression: A postfix unary expression.
PrefixedIdentifier: An identifier that is prefixed or an access to an object property where the target of the property access is a simple identifier.
PrefixExpression: A prefix unary expression.
PropertyAccess: The access of a property of an object.
RecordLiteral: A record literal.
RecordPattern: A record pattern.
RecordTypeAnnotation: A record type.
RecordTypeAnnotationField: A field in a RecordTypeAnnotation.
RecordTypeAnnotationNamedField: A named field in a RecordTypeAnnotation.
RecordTypeAnnotationNamedFields: The portion of a RecordTypeAnnotation with named fields.
RecordTypeAnnotationPositionalField: A positional field in a RecordTypeAnnotation.
RedirectingConstructorInvocation: The invocation of a constructor in the same class from within a constructor's initialization list.
RelationalPattern: A relational pattern.
RestPatternElement: A rest pattern element.
RethrowExpression: A rethrow expression.
ReturnStatement: A return statement.
ScriptTag: A script tag that can optionally occur at the beginning of a compilation unit.
SetOrMapLiteral: A set or map literal.
ShowCombinator: A combinator that restricts the names being imported to those in a given list.
SimpleFormalParameter: A simple formal parameter.
SimpleIdentifier: A simple identifier.
SimpleStringLiteral: A string literal expression that does not contain any interpolations.
SingleStringLiteral: A single string literal expression.
SpreadElement: A spread element.
Statement: A node that represents a statement.
StringInterpolation: A string interpolation literal.
StringLiteral: A string literal expression.
SuperConstructorInvocation: The invocation of a superclass' constructor from within a constructor's initialization list.
SuperExpression: A super expression.
SuperFormalParameter: A super-initializer formal parameter.
SwitchCase: A case in a switch statement.
SwitchDefault: The default case in a switch statement.
SwitchExpression: A switch expression.
SwitchExpressionCase: A case in a switch expression.
SwitchMember: An element within a switch statement.
SwitchPatternCase: A pattern-based case in a switch statement.
SwitchStatement: A switch statement.
SymbolLiteral: A symbol literal expression.
ThisExpression: A this expression.
ThrowExpression: A throw expression.
TopLevelVariableDeclaration: The declaration of one or more top-level variables of the same type.
TryStatement: A try statement.
TypeAlias: The declaration of a type alias.
TypeAnnotation: A type annotation.
TypeArgumentList: A list of type arguments.
TypedLiteral: A literal that has a type associated with it.
TypeLiteral: An expression representing a type, e.g. the expression int in var x = int;.
TypeParameter: A type parameter.
TypeParameterList: Type parameters within a declaration.
UriBasedDirective: A directive that references a URI.
VariableDeclaration: An identifier that has an initial value associated with it.
VariableDeclarationList: The declaration of one or more variables of the same type.
VariableDeclarationStatement: A list of variables that are being declared in a context where a statement is required.
VariablePattern: The shared interface of AssignedVariablePattern and DeclaredVariablePattern.
WhenClause: A guard in a pattern-based case in a switch statement, switch expression, if statement, or if element.
WhileStatement: A while statement.
WildcardPattern: A wildcard pattern.
WithClause: The with clause in a class declaration.
YieldStatement: A yield statement.

dart/ast/ast library

Classes

analyzer package

ast library