Typescript Node Types

TypeScript language node type mappings for AST semantic extraction

Language Characteristics

• Superset of JavaScript: Includes all JS constructs via #include
• Static typing: Compile-time type checking with structural typing
• Interfaces: Contract definitions for object shapes (ABSTRACT refinement)
• Type aliases: Named types via type keyword
• Enums: Enumerated types (ENUM refinement)
• Generics: Type parameters with constraints
• Access modifiers: public, private, protected, readonly
• Decorators: Metadata annotations via @decorator syntax
• Declaration files: .d.ts ambient declarations
• Namespaces/modules: Code organization constructs

Semantic Type Encoding

Semantic types use 8-bit encoding: - Bits 7-2: Base category (e.g., DEFINITION_CLASS = 0x0C) - Bits 1-0: Refinement within category

Example: DEFINITION_CLASS | SemanticRefinements::Class::ABSTRACT - Base: 0x0C (class definition) - Refinement: 0x01 (abstract/interface) - Combined: 0x0D

Node Categories

• Type System Constructs
• Type Annotations and References
• Composite Types
• Literal Types
• Generic/Template Types
• Advanced Type Constructs
• Type Operators and Utilities
• Access Modifiers and Visibility
• Declaration Constructs
• Import/Export with Types
• Type Assertions and Guards
• Class-Specific Constructs
• Function Parameters
• Function Calls and Expressions
• Control Flow
• Exception Handling
• Pattern Matching and Destructuring
• TypeScript-Specific Keywords
• Primitive Type Keywords
• Special References and Identifiers
• Literals and Values
• TypeScript Operators
• Expressions
• Delimiters and Punctuation
• Parser Errors

Type System Constructs

TypeScript's static type system definitions

TypeScript adds a rich type system on top of JavaScript. These nodes represent type declarations, interfaces, and type signatures that exist only at compile time and are erased during transpilation.

Node Type	Semantic Type	Name Extraction	Description
type_alias_declaration	DEFINITION_CLASS	FIND_IDENTIFIER	Type alias declaration: type Name = SomeType
interface_declaration	DEFINITION_CLASS	Class::ABSTRACT	FIND_IDENTIFIER
property_signature	DEFINITION_VARIABLE	Variable::FIELD	FIND_IDENTIFIER
method_signature	DEFINITION_FUNCTION	Function::REGULAR	FIND_IDENTIFIER
construct_signature	DEFINITION_FUNCTION	Function::CONSTRUCTOR	NONE
call_signature	DEFINITION_FUNCTION	Function::REGULAR	NONE
index_signature	DEFINITION_VARIABLE	Variable::FIELD	NONE
function_signature	DEFINITION_FUNCTION	Function::REGULAR	FIND_IDENTIFIER

Type Annotations and References

Type annotations attached to declarations

These nodes represent type annotations (: Type), type identifiers, and predefined primitive types.

Node Type	Semantic Type	Name Extraction	Description
type_annotation	TYPE_REFERENCE	NONE	Type annotations attached to declarations
type_identifier	TYPE_REFERENCE	NODE_TEXT
predefined_type	TYPE_PRIMITIVE	NODE_TEXT
this_type	TYPE_REFERENCE	NODE_TEXT
nested_type_identifier	TYPE_REFERENCE	NODE_TEXT

Composite Types

Union, intersection, array, tuple, and other composite types

TypeScript's type combinators allow building complex types from simpler ones.

Node Type	Semantic Type	Name Extraction	Description
union_type	TYPE_COMPOSITE	NONE	Union, intersection, array, tuple, and other composite types
intersection_type	TYPE_COMPOSITE	NONE
array_type	TYPE_COMPOSITE	NONE
tuple_type	TYPE_COMPOSITE	NONE
object_type	TYPE_COMPOSITE	NONE
function_type	TYPE_COMPOSITE	NONE
constructor_type	TYPE_COMPOSITE	NONE
template_literal_type	TYPE_COMPOSITE	NONE
template_type	TYPE_COMPOSITE	NONE

Literal Types

Types representing specific literal values

TypeScript allows literal values as types for precise type narrowing.

Node Type	Semantic Type	Name Extraction	Description
literal_type	TYPE_PRIMITIVE	NODE_TEXT	Types representing specific literal values
string_literal_type	TYPE_PRIMITIVE	NODE_TEXT
number_literal_type	TYPE_PRIMITIVE	NODE_TEXT
boolean_literal_type	TYPE_PRIMITIVE	NODE_TEXT

Generic/Template Types

Parameterized types and type parameters

TypeScript supports generics with constraints and defaults.

Node Type	Semantic Type	Name Extraction	Description
type_parameters	TYPE_GENERIC	NONE	Parameterized types and type parameters
type_parameter	TYPE_GENERIC	FIND_IDENTIFIER
type_arguments	TYPE_GENERIC	NONE
generic_type	TYPE_GENERIC	NONE
constraint	TYPE_REFERENCE	NONE
default_type	TYPE_REFERENCE	NONE

Advanced Type Constructs

Conditional types, mapped types, indexed access, and inference

TypeScript's advanced type-level programming features.

Node Type	Semantic Type	Name Extraction	Description
conditional_type	TYPE_REFERENCE	NONE	Conditional types, mapped types, indexed access, and inference
infer_type	TYPE_REFERENCE	NONE
mapped_type_clause	TYPE_REFERENCE	NONE
indexed_access_type	TYPE_REFERENCE	NONE
parenthesized_type	TYPE_REFERENCE	NONE
lookup_type	TYPE_REFERENCE	NONE
index_type_query	TYPE_REFERENCE	NONE
type_query	TYPE_REFERENCE	NONE
extends_type_clause	TYPE_REFERENCE	NONE
flow_maybe_type	TYPE_REFERENCE	NONE

Type Operators and Utilities

Built-in type operators for type manipulation

Node Type	Semantic Type	Name Extraction	Description
typeof_type	TYPE_REFERENCE	NONE	Built-in type operators for type manipulation
keyof_type	TYPE_REFERENCE	NONE
readonly_type	TYPE_REFERENCE	NONE
asserts	TYPE_REFERENCE	NONE
asserts_annotation	TYPE_REFERENCE	NONE
opting_type_annotation	TYPE_REFERENCE	NONE
type_predicate_annotation	TYPE_REFERENCE	NONE

Access Modifiers and Visibility

TypeScript access control keywords

Unlike JavaScript, TypeScript has compile-time access modifiers. These are mapped to METADATA_ANNOTATION as they affect visibility.

Node Type	Semantic Type	Name Extraction	Description
accessibility_modifier	METADATA_ANNOTATION	NODE_TEXT	TypeScript access control keywords
public	METADATA_ANNOTATION	NODE_TEXT
private	METADATA_ANNOTATION	NODE_TEXT
protected	METADATA_ANNOTATION	NODE_TEXT
readonly	METADATA_ANNOTATION	NODE_TEXT
static	METADATA_ANNOTATION	NODE_TEXT
abstract	METADATA_ANNOTATION	NODE_TEXT
override_modifier	METADATA_ANNOTATION	NODE_TEXT
override	METADATA_ANNOTATION	NONE
get	METADATA_ANNOTATION	NONE
set	METADATA_ANNOTATION	NONE
global	METADATA_ANNOTATION	NONE

Declaration Constructs

TypeScript-specific declaration types

Includes enums, namespaces, modules, and ambient declarations.

Node Type	Semantic Type	Name Extraction	Description
ambient_declaration	DEFINITION_MODULE	NONE	TypeScript-specific declaration types
declaration_list	ORGANIZATION_LIST	NONE
enum_declaration	DEFINITION_CLASS	Class::ENUM	FIND_IDENTIFIER
enum_assignment	DEFINITION_VARIABLE	Variable::IMMUTABLE	FIND_IDENTIFIER
module_declaration	DEFINITION_MODULE	FIND_IDENTIFIER
namespace_declaration	DEFINITION_MODULE	FIND_IDENTIFIER
internal_module	DEFINITION_MODULE	FIND_IDENTIFIER

Import/Export with Types

TypeScript import/export extensions for types

Node Type	Semantic Type	Name Extraction	Description
import_type_clause	EXTERNAL_IMPORT	NONE	TypeScript import/export extensions for types
export_type_clause	EXTERNAL_EXPORT	NONE
import_specifier	EXTERNAL_IMPORT	FIND_IDENTIFIER
export_specifier	EXTERNAL_EXPORT	FIND_IDENTIFIER
import_require_clause	EXTERNAL_IMPORT	NONE
external_module_reference	EXTERNAL_IMPORT	NONE
named_imports	EXTERNAL_IMPORT	Import::SELECTIVE	NONE
from	EXTERNAL_IMPORT	NONE

Type Assertions and Guards

Runtime and compile-time type narrowing

Node Type	Semantic Type	Name Extraction	Description
type_assertion	TYPE_REFERENCE	NONE	Runtime and compile-time type narrowing
as_expression	TYPE_REFERENCE	NONE
non_null_expression	TYPE_REFERENCE	NONE
satisfies_expression	TYPE_REFERENCE	NONE
type_predicate	TYPE_REFERENCE	NONE

Class-Specific Constructs

TypeScript class extensions

Node Type	Semantic Type	Name Extraction	Description
abstract_class_declaration	DEFINITION_CLASS	Class::ABSTRACT	FIND_IDENTIFIER
abstract_method_signature	DEFINITION_FUNCTION	Function::REGULAR	FIND_IDENTIFIER
parameter_property	DEFINITION_VARIABLE	Variable::PARAMETER	FIND_IDENTIFIER
public_field_definition	DEFINITION_VARIABLE	Variable::FIELD	FIND_IDENTIFIER
class_heritage	TYPE_REFERENCE	NONE
implements_clause	TYPE_REFERENCE	NONE
extends_clause	TYPE_REFERENCE	NONE
class_body	ORGANIZATION_BLOCK	NONE
interface_body	ORGANIZATION_BLOCK	NONE
enum_body	ORGANIZATION_BLOCK	NONE

Function Parameters

TypeScript function parameter types

Node Type	Semantic Type	Name Extraction	Description
required_parameter	DEFINITION_VARIABLE	Variable::PARAMETER	FIND_IDENTIFIER
optional_parameter	DEFINITION_VARIABLE	Variable::PARAMETER	FIND_IDENTIFIER
rest_parameter	PATTERN_COLLECT	FIND_IDENTIFIER
decorator	NAME_ATTRIBUTE	FIND_IDENTIFIER

Function Calls and Expressions

Call expressions with TypeScript refinements

Node Type	Semantic Type	Name Extraction	Description
call_expression	COMPUTATION_CALL	Call::FUNCTION	FIND_CALL_TARGET
new_expression	COMPUTATION_CALL	Call::CONSTRUCTOR	FIND_CALL_TARGET
instantiation_expression	COMPUTATION_CALL	NONE

Control Flow

Control flow statements and expressions

Node Type	Semantic Type	Name Extraction	Description
labeled_statement	EXECUTION_STATEMENT	FIND_IDENTIFIER	Control flow statements and expressions
else_clause	FLOW_CONDITIONAL	NONE
switch	FLOW_CONDITIONAL	Conditional::MULTIWAY	NONE
switch_body	ORGANIZATION_BLOCK	Organization::SEQUENTIAL	NONE
switch_default	FLOW_CONDITIONAL	Conditional::MULTIWAY	NONE
default_clause	FLOW_CONDITIONAL	Conditional::MULTIWAY	NONE
switch_case	FLOW_CONDITIONAL	Conditional::MULTIWAY	NONE
case_clause	FLOW_CONDITIONAL	Conditional::MULTIWAY	NONE
default	FLOW_CONDITIONAL	NONE
ternary_expression	FLOW_CONDITIONAL	Conditional::TERNARY	NONE
break	FLOW_JUMP	Jump::BREAK	NONE
continue	FLOW_JUMP	Jump::CONTINUE	NONE
do	FLOW_LOOP	NONE
yield	FLOW_SYNC	NONE

Exception Handling

Try/catch/finally and throw statements

Node Type	Semantic Type	Name Extraction	Description
throw	ERROR_THROW	NONE	Try/catch/finally and throw statements
try	ERROR_TRY	NONE
catch	ERROR_CATCH	NONE
finally	ERROR_FINALLY	NONE

Pattern Matching and Destructuring

Destructuring patterns for arrays and objects

Node Type	Semantic Type	Name Extraction	Description
variable_declarator	DEFINITION_VARIABLE	Variable::MUTABLE	FIND_IDENTIFIER
assignment_pattern	PATTERN_DESTRUCTURE	FIND_IDENTIFIER
object_pattern	PATTERN_DESTRUCTURE	NONE
array_pattern	PATTERN_DESTRUCTURE	NONE
rest_pattern	PATTERN_COLLECT	NONE
spread_element	PATTERN_COLLECT	NONE
shorthand_property_identifier_pattern	PATTERN_DESTRUCTURE	NODE_TEXT
pair_pattern	PATTERN_DESTRUCTURE	NONE
object_assignment_pattern	PATTERN_DESTRUCTURE	NONE

TypeScript-Specific Keywords

Reserved words specific to TypeScript

Node Type	Semantic Type	Name Extraction	Description
type	TYPE_REFERENCE	NONE	Reserved words specific to TypeScript
interface	DEFINITION_CLASS	NONE
enum	DEFINITION_CLASS	NONE
namespace	DEFINITION_MODULE	NONE
module	DEFINITION_MODULE	NONE
declare	METADATA_ANNOTATION	NONE
keyof	TYPE_REFERENCE	NONE
typeof	TYPE_REFERENCE	NONE
infer	TYPE_REFERENCE	NONE
extends	TYPE_REFERENCE	NONE
implements	TYPE_REFERENCE	NONE
as	TYPE_REFERENCE	NONE
is	TYPE_REFERENCE	NONE
satisfies	TYPE_REFERENCE	NONE
of	OPERATOR_COMPARISON	NONE
delete	EXECUTION_STATEMENT	NONE
new	COMPUTATION_CALL	NONE

Primitive Type Keywords

Built-in primitive type names

Node Type	Semantic Type	Name Extraction	Description
boolean	TYPE_PRIMITIVE	NODE_TEXT	Built-in primitive type names
string	TYPE_PRIMITIVE	NODE_TEXT
number	TYPE_PRIMITIVE	NODE_TEXT
bigint	TYPE_PRIMITIVE	NODE_TEXT
symbol	TYPE_PRIMITIVE	NODE_TEXT
object	TYPE_PRIMITIVE	NODE_TEXT
any	TYPE_PRIMITIVE	NODE_TEXT
unknown	TYPE_PRIMITIVE	NODE_TEXT
never	TYPE_PRIMITIVE	NODE_TEXT
void	TYPE_PRIMITIVE	NODE_TEXT

Special References and Identifiers

Special identifier nodes

Node Type	Semantic Type	Name Extraction	Description
this	NAME_SCOPED	NODE_TEXT	Special identifier nodes
super	NAME_SCOPED	NODE_TEXT
shorthand_property_identifier	NAME_IDENTIFIER	NODE_TEXT
nested_identifier	NAME_QUALIFIED	NODE_TEXT
target	NAME_IDENTIFIER	NODE_TEXT
meta	METADATA_ANNOTATION	NODE_TEXT

Literals and Values

String, template, and regex literals

Node Type	Semantic Type	Name Extraction	Description
template_literal_type_span	LITERAL_STRING	NONE	String, template, and regex literals
template_substitution	LITERAL_STRING	NONE
regex	LITERAL_STRING	NODE_TEXT
regex_pattern	LITERAL_STRING	NODE_TEXT
regex_flags	LITERAL_STRING	NODE_TEXT
escape_sequence	LITERAL_STRING	NONE
property_assignment	LITERAL_STRUCTURED	FIND_IDENTIFIER
computed_property_name	COMPUTATION_EXPRESSION	NONE

TypeScript Operators

Operators including TypeScript-specific ones

Node Type	Semantic Type	Name Extraction	Description
=>	OPERATOR_ASSIGNMENT	NONE	Operators including TypeScript-specific ones
?.	COMPUTATION_ACCESS	NONE
optional_chain	COMPUTATION_ACCESS	NONE
?	OPERATOR_LOGICAL	NONE
??	OPERATOR_LOGICAL	NONE
!	OPERATOR_LOGICAL	NONE
?:	OPERATOR_LOGICAL	NONE
augmented_assignment_expression	OPERATOR_ASSIGNMENT	Assignment::COMPOUND	NONE
...	PATTERN_COLLECT	NODE_TEXT

Expressions

Expression nodes

Node Type	Semantic Type	Name Extraction	Description
sequence_expression	COMPUTATION_EXPRESSION	NONE	Expression nodes
parenthesized_expression	COMPUTATION_EXPRESSION	NONE
empty_statement	EXECUTION_STATEMENT	NONE

Delimiters and Punctuation

Syntactic punctuation tokens

Node Type	Semantic Type	Name Extraction	Description
```	PARSER_DELIMITER	NONE	Syntactic punctuation tokens
<	PARSER_DELIMITER	NONE
>	PARSER_DELIMITER	NONE

Parser Errors

Error nodes from parsing

Node Type	Semantic Type	Name Extraction	Description
ERROR	PARSER_SYNTAX	NODE_TEXT	Error nodes from parsing

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Generated from typescript_types.def