js/jasminesnake/ast/nodes.py

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"""The module with AST nodes declaration. They are ESTree compliant.
The module lacks support of:
* ES5 features:
* labelled statements
* switch statements
* try-catch statements
* debugger statement
* with statement
* RegExp
* ES6 features:
* generators/yield statement
* for-of statement
* template literals
* and other ES6 features :)
More about ESTree standard:
https://github.com/estree/estree/
Todo:
* Add support for lacking features
"""
from typing import List, Union, Optional, Literal as TypeLiteral, TypedDict
from enum import Enum
# The Lord sees I actually wanted to split it up, but ESTree hierarchy is so messed up... No. It's actually *fucked up*
# that much that I couldn't even resolve circular dependencies in the submodules. I have to reap what I've sown.
# Custom types used in the nodes
number = Union[int, float]
"""A type union consisting of int and float Python types. Consider it as Number type from JavaScript."""
SourceTypeLiteral = TypeLiteral["script", "module"]
"""The type for the `sourceType` field."""
VarDeclKind = TypeLiteral["var", "let", "const"]
"""The type for the `kind` field of `VariableDeclaration`."""
PropKind = TypeLiteral["init", "get", "set"]
"""A type for a `kind` field of `Property`."""
class UnaryOperator(Enum):
"""A unary operator token."""
MINUS = "-"
PLUS = "+"
NOT_LOGIC = "!"
NOT_BIT = "~"
TYPEOF = "typeof"
VOID = "void"
DELETE = "delete"
class UpdateOperator(Enum):
"""An update (increment or decrement) operator token."""
INCREMENT = "++"
DECREMENT = "--"
class BinaryOperator(Enum):
"""A binary operator token."""
EQ = "=="
NEQ = "!="
EQ_IDENTITY = "==="
NEQ_IDENTITY = "!=="
LT = "<"
LTE = "<="
GT = ">"
GTE = ">="
SHL = "<<"
SHR = ">>"
SHR_LOGIC = ">>>"
ADD = "+"
SUB = "-"
MUL = "*"
DIV = "/"
MOD = "%"
OR = "|"
XOR = "^"
AND = "&"
IN = "in"
INSTANCEOF = "instanceof"
class AssignmentOperator(Enum):
"""An assignment operator token."""
ASSIGN = "="
ADD = "+="
SUB = "-="
MUL = "*="
DIV = "/="
MOD = "%="
SHL = "<<="
SHR = ">>="
SHR_LOGIC = ">>>="
OR = "|="
XOR = "^="
AND = "&="
class LogicalOperator(Enum):
"""A logical operator token."""
OR = "||"
AND = "&&"
# Nodes forward declarations
class Expression:
...
class Pattern:
...
class Directive:
...
class Statement:
...
class FunctionBody:
...
class VariableDeclaration:
...
class Property:
...
# "Node objects" block
class Position:
"""The class for an object consisting of a line number (1-indexed) and a column number (0-indexed)."""
def __init__(self, line: int, column: int):
if line < 1 or column < 0:
raise ValueError(
"L{}:C{} is not valid ESTree position!".format(line, column)
)
self.line = line
self.column = column
class SourceLocation:
"""
The class for the source location information of a node.
Consists of a start position (the position of the first character of the parsed source region) and an end
position (the position of the first character after the parsed source region).
See Also:
Position
"""
def __init__(self, source: Optional[str], start: Position, end: Position):
self.source = source
self.start = start
self.end = end
class Node:
"""ESTree AST nodes are represented as Node objects, which may have any prototype inheritance but which implement
this interface.
The `type` field is a string representing the AST variant type. Each subtype of `Node` is documented below with
the specific string of its `type` field. You can use this field to determine which interface a node implements.
The `loc` field represents the source location information of the node. If the node contains no information about
the source location, the field is `None`; otherwise it contains a `SourceLocation` object.
See Also:
SourceLocation
"""
def __init__(self, node_type: str, loc: Optional[SourceLocation]):
self.type = node_type
self.loc = loc
# "Identifier" block
class Identifier(Expression, Pattern):
"""An identifier. Note that an identifier may be an expression or a destructuring pattern."""
def __init__(self, loc: Optional[SourceLocation], name: str):
super(Identifier, self).__init__("Identifier", loc)
self.name = name
# "Literal" block
class Literal(Expression):
"""A literal token. Note that a literal can be an expression."""
def __init__(
self, loc: Optional[SourceLocation], value: Union[str, bool, number, None]
):
super().__init__("Literal", loc)
self.value = value
# "Programs" block
class Program(Node):
"""A complete program source tree."""
def __init__(
self,
loc: Optional[SourceLocation],
source_type: SourceTypeLiteral,
body: List[Union[Directive, Statement]],
):
super().__init__("Program", loc)
self.body = body
self.source_type = source_type
# "Functions" block
class Function(Node):
"""A function declaration or expression.
See Also:
FunctionDeclaration
FunctionExpression
FunctionBody
"""
def __init__(
self,
node_type: str,
loc: Optional[SourceLocation],
function_id: Optional[Identifier],
params: List[Pattern],
body: FunctionBody,
):
super().__init__(node_type, loc)
self.id = function_id
self.params = params
self.body = body
# "Statements" block
class Statement(Node):
"""Any statement."""
def __init__(self, node_type: str, loc: Optional[SourceLocation]):
super().__init__(node_type, loc)
class EmptyStatement(Statement):
"""An empty statement, i.e., a solitary semicolon."""
def __init__(self, loc: Optional[SourceLocation]):
super().__init__("EmptyStatement", loc)
class BlockStatement(Statement):
"""A block statement, i.e., a sequence of statements surrounded by braces."""
def __init__(self, loc: Optional[SourceLocation], body: List[Statement]):
super().__init__("BlockStatement", loc)
self.body = body
class ExpressionStatement(Statement):
"""An expression statement, i.e., a statement consisting of a single expression."""
def __init__(self, loc: Optional[SourceLocation], expression: Expression):
super().__init__("ExpressionStatement", loc)
self.expression = expression
class Directive(Node):
"""A directive from the directive prologue of a script or function. The `directive` property is the raw string
source of the directive without quotes.
"""
def __init__(
self, loc: Optional[SourceLocation], expression: Literal, directive: str
):
super().__init__("Directive", loc)
self.expression = expression
self.directive = directive
class FunctionBody(BlockStatement):
"""The body of a function, which is a block statement that may begin with directives."""
def __init__(
self, loc: Optional[SourceLocation], body: List[Union[Directive, Statement]]
):
super().__init__(loc, body)
class ReturnStatement(Statement):
"""A `return` statement."""
def __init__(self, loc: Optional[SourceLocation], argument: Optional[Expression]):
super().__init__("ReturnStatement", loc)
self.argument = argument
class BreakStatement(Statement):
"""A `break` statement."""
def __init__(self, loc: Optional[SourceLocation], label: Optional[Identifier]):
super().__init__("BreakStatement", loc)
self.label = label
class ContinueStatement(Statement):
"""A `continue` statement."""
def __init__(self, loc: Optional[SourceLocation], label: Optional[Identifier]):
super().__init__("ContinueStatement", loc)
self.label = label
class IfStatement(Statement):
"""An `if` statement."""
def __init__(
self,
loc: Optional[SourceLocation],
test: Expression,
consequent: Statement,
alternate: Optional[Statement],
):
super().__init__("IfStatement", loc)
self.test = test
self.consequent = consequent
self.alternate = alternate
class WhileStatement(Statement):
"""A `while` statement."""
def __init__(
self, loc: Optional[SourceLocation], test: Expression, body: Statement
):
super().__init__("WhileStatement", loc)
self.test = test
self.body = body
class DoWhileStatement(Statement):
"""A `do`/`while` statement."""
def __init__(
self, loc: Optional[SourceLocation], body: Statement, test: Expression
):
super().__init__("DoWhileStatement", loc)
self.body = body
self.test = test
class ForStatement(Statement):
"""A `for` statement."""
def __init__(
self,
loc: Optional[SourceLocation],
init: Union[VariableDeclaration, Expression, None],
test: Optional[Expression],
update: Optional[Expression],
body: Statement,
):
super().__init__("ForStatement", loc)
self.init = init
self.test = test
self.update = update
self.body = body
class ForInStatement(Statement):
"""A `for`/`in` statement."""
def __init__(
self,
loc: Optional[SourceLocation],
left: Union[VariableDeclaration, Pattern],
right: Expression,
body: Statement,
):
super().__init__("ForInStatement", loc)
self.left = left
self.right = right
self.body = body
# "Declarations" block
class Declaration(Statement):
"""Any declaration node. Note that declarations are considered statements; this is because declarations can
appear in any statement context. """
def __init__(self, node_type: str, loc: Optional[SourceLocation]):
super().__init__(node_type, loc)
class FunctionDeclaration(Function, Declaration):
"""A function declaration. Note that unlike in the parent interface `Function`, the `id` cannot be `None`."""
def __init__(
self,
loc: Optional[SourceLocation],
function_id: Identifier,
params: List[Pattern],
body: FunctionBody,
):
super().__init__("FunctionDeclaration", loc, function_id, params, body)
class VariableDeclarator(Node):
"""A variable declarator."""
def __init__(
self, loc: Optional[SourceLocation], var_id: Pattern, init: Optional[Exception]
):
super().__init__("VariableDeclarator", loc)
self.id = var_id
self.init = init
class VariableDeclaration(Declaration):
"""A variable declaration."""
def __init__(
self,
loc: Optional[SourceLocation],
kind: VarDeclKind,
declarations: List[VariableDeclarator],
):
super().__init__("VariableDeclaration", loc)
self.declarations = declarations
self.kind = kind
# "Expressions" block
class Expression(Node):
"""Any expression node. Since the left-hand side of an assignment may be any expression in general, an expression
can also be a pattern.
See Also:
Pattern
"""
def __init__(self, node_type: str, loc: Optional[SourceLocation]):
super().__init__(node_type, loc)
class Super(Node):
"""A ``super`` pseudo-expression."""
def __init__(self, loc: Optional[SourceLocation]):
super().__init__("Super", loc)
class SpreadElement(Node):
"""Spread expression, e.g., ``[head, ...iter, tail]``, ``f(head, ...iter, ...tail)``."""
def __init__(self, loc: Optional[SourceLocation], argument: Expression):
super().__init__("SpreadElement", loc)
self.argument = argument
class ThisExpression(Expression):
"""A `this` expression."""
def __init__(self, loc: Optional[SourceLocation]):
super().__init__("ThisExpression", loc)
class ArrayExpression(Expression):
"""An array expression. An element might be `None` if it represents a hole in a sparse array. E.g. ``[1,,2]``."""
def __init__(
self,
loc: Optional[SourceLocation],
elements: List[Union[Expression, SpreadElement, None]],
):
super().__init__("ArrayExpression", loc)
self.elements = elements
class ObjectExpression(Expression):
"""An object expression."""
def __init__(self, loc: Optional[SourceLocation], properties: List[Property]):
super().__init__("ObjectExpression", loc)
self.properties = properties
class FunctionExpression(Function, Expression):
"""A function expression."""
def __init__(
self,
loc: Optional[SourceLocation],
function_id: Optional[Identifier],
params: List[Pattern],
body: FunctionBody,
):
super().__init__("FunctionExpression", loc, function_id, params, body)
class ArrowFunctionExpression(Function, Expression):
"""A fat arrow function expression, e.g., ``let foo = (bar) => { /* body */ }``."""
def __init__(
self,
loc: Optional[SourceLocation],
params: List[Pattern],
body: Union[FunctionBody, Expression],
expression: bool,
):
super().__init__("ArrowFunctionExpression", loc, None, params, body)
self.expression = expression
class UnaryExpression(Expression):
"""A unary operator expression."""
def __init__(
self,
loc: Optional[SourceLocation],
operator: UnaryOperator,
prefix: bool,
argument: Expression,
):
super().__init__("UnaryExpression", loc)
self.operator = operator
self.prefix = prefix
self.argument = argument
class UpdateExpression(Expression):
"""An update (increment or decrement) operator expression."""
def __init__(
self,
loc: Optional[SourceLocation],
operator: UpdateOperator,
argument: Expression,
prefix: bool,
):
super().__init__("UpdateExpression", loc)
self.operator = operator
self.argument = argument
self.prefix = prefix
class BinaryExpression(Expression):
"""A binary operator expression."""
def __init__(
self,
loc: Optional[SourceLocation],
operator: BinaryOperator,
left: Expression,
right: Expression,
):
super().__init__("BinaryExpression", loc)
self.operator = operator
self.left = left
self.right = right
class AssignmentExpression(Expression):
"""An assignment operator expression."""
def __init__(
self,
loc: Optional[SourceLocation],
operator: AssignmentOperator,
left: Union[
Pattern, Expression
], # Left for backwards compatibility with pre-ES6 code, should be `Pattern`
right: Expression,
):
super().__init__("AssignmentExpression", loc)
self.operator = operator
self.left = left
self.right = right
class LogicalExpression(Expression):
"""A logical operator expression."""
def __init__(
self,
loc: Optional[SourceLocation],
operator: LogicalOperator,
left: Union[Pattern, Expression],
right: Expression,
):
super().__init__("LogicalExpression", loc)
self.operator = operator
self.left = left
self.right = right
class MemberExpression(Expression, Pattern):
"""A member expression. If `computed` is ``True``, the node corresponds to a computed (``a[b]``) member
expression and `property` is an `Expression`. If `computed` is `False`, the node corresponds to a static
(``a.b``) member expression and `property` is an `Identifier`. """
def __init__(
self,
loc: Optional[SourceLocation],
member_object: Union[Expression, Super],
member_property: Expression,
computed: bool,
):
super().__init__("MemberExpression", loc)
self.object = member_object
self.property = member_property
self.computed = computed
class ConditionalExpression(Expression):
"""A conditional expression, i.e., a ternary ``?``/``:`` expression."""
def __init__(
self,
loc: Optional[SourceLocation],
test: Expression,
alternate: Expression,
consequent: Expression,
):
super().__init__("ConditionalExpression", loc)
self.test = test
self.alternate = alternate
self.consequent = consequent
class CallExpression(Expression):
"""A function or method call expression."""
def __init__(
self,
loc: Optional[SourceLocation],
callee: Union[Expression, Super],
arguments: List[Union[Expression, SpreadElement]],
):
super().__init__("CallExpression", loc)
self.callee = callee
self.arguments = arguments
class NewExpression(Expression):
"""A ``new`` expression."""
def __init__(
self,
loc: Optional[SourceLocation],
callee: Expression,
arguments: List[Union[Expression, SpreadElement]],
):
super().__init__("NewExpression", loc)
self.callee = callee
self.arguments = arguments
class SequenceExpression(Expression):
"""A sequence expression, i.e., a comma-separated sequence of expressions."""
def __init__(self, loc: Optional[SourceLocation], expressions: List[Expression]):
super().__init__("SequenceExpression", loc)
self.expressions = expressions
def _generate_unary_expression(operator: UnaryOperator, docstring: str):
"""Internal function to generate unary expression AST node.
Implying that all UnaryExpression nodes are prefix.
"""
class Expr(UnaryExpression):
__doc__ = docstring
def __init__(self, loc: Optional[SourceLocation], argument: Expression):
super().__init__(loc, operator, True, argument)
return Expr
def _generate_update_expression(operator: UpdateOperator, prefix: bool, docstring: str):
"""Internal function to generate update expression AST node."""
class Expr(UpdateExpression):
__doc__ = docstring
def __init__(self, loc: Optional[SourceLocation], argument: Expression):
super().__init__(loc, operator, argument, prefix)
return Expr
def _generate_binary_expression(operator: BinaryOperator, docstring: str):
"""Internal function to generate binary expression AST node."""
class Expr(BinaryExpression):
__doc__ = docstring
def __init__(
self, loc: Optional[SourceLocation], left: Expression, right: Expression
):
super().__init__(loc, operator, left, right)
return Expr
def _generate_assignment_expression(operator: AssignmentOperator, docstring: str):
"""Internal function to generate assignment expression AST node."""
class Expr(AssignmentExpression):
__doc__ = docstring
def __init__(
self,
loc: Optional[SourceLocation],
left: Union[Pattern, Expression],
right: Expression,
):
super().__init__(loc, operator, left, right)
return Expr
def _generate_logical_expression(operator: LogicalOperator, docstring: str):
"""Internal function to generate logical expression AST node."""
class Expr(LogicalExpression):
__doc__ = docstring
def __init__(
self,
loc: Optional[SourceLocation],
left: Union[Pattern, Expression],
right: Expression,
):
super().__init__(loc, operator, left, right)
return Expr
UnaryMinusExpression = _generate_unary_expression(
UnaryOperator.MINUS, """A unary minus expression."""
)
UnaryPlusExpression = _generate_unary_expression(
UnaryOperator.PLUS, """A unary plus expression."""
)
UnaryLogicNotExpression = _generate_unary_expression(
UnaryOperator.NOT_LOGIC, """A unary logic "not" expression."""
)
UnaryBitNotExpression = _generate_unary_expression(
UnaryOperator.NOT_BIT, """A unary bit "not" expression."""
)
TypeofExpression = _generate_unary_expression(
UnaryOperator.TYPEOF, """A `typeof` expression."""
)
VoidExpression = _generate_unary_expression(
UnaryOperator.VOID, """A `void` expression."""
)
DeleteExpression = _generate_unary_expression(
UnaryOperator.DELETE, """A `delete` expression."""
)
PreIncrementExpression = _generate_update_expression(
UpdateOperator.INCREMENT, True, """A pre-increment expression."""
)
PostIncrementExpression = _generate_update_expression(
UpdateOperator.INCREMENT, False, """A post-increment expression."""
)
PreDecrementExpression = _generate_update_expression(
UpdateOperator.DECREMENT, True, """A pre-decrement expression."""
)
PostDecrementExpression = _generate_update_expression(
UpdateOperator.DECREMENT, False, """A post-decrement expression."""
)
EqualityExpression = _generate_binary_expression(
BinaryOperator.EQ, """An equality expression."""
)
NotEqualityExpression = _generate_binary_expression(
BinaryOperator.NEQ, """A "not equality" expression."""
)
IdentityEqualityExpression = _generate_binary_expression(
BinaryOperator.EQ_IDENTITY, """An identity equality expression."""
)
NotIdentityEqualityExpression = _generate_binary_expression(
BinaryOperator.NEQ_IDENTITY, """A "not identity equality" expression."""
)
LowerThanRelationExpression = _generate_binary_expression(
BinaryOperator.LT, """A "lower than" expression."""
)
LowerThanEqualRelationExpression = _generate_binary_expression(
BinaryOperator.LTE, """A "lower than or equal" expression."""
)
GreaterThanRelationExpression = _generate_binary_expression(
BinaryOperator.GT, """A "greater than" expression."""
)
GreaterThanEqualRelationExpression = _generate_binary_expression(
BinaryOperator.GTE, """A "greater than or equal" expression."""
)
LeftBitShiftExpression = _generate_binary_expression(
BinaryOperator.SHL, """A "left bit shift" expression."""
)
RightBitShiftExpression = _generate_binary_expression(
BinaryOperator.SHR, """A "right bit shift" expression."""
)
LogicRightBitShiftExpression = _generate_binary_expression(
BinaryOperator.SHR_LOGIC, """A "logical right bit shift" expression."""
)
AddArithmeticExpression = _generate_binary_expression(
BinaryOperator.ADD, """An addition arithmetical expression."""
)
SubArithmeticExpression = _generate_binary_expression(
BinaryOperator.SUB, """A subtraction arithmetical expression."""
)
MulArithmeticExpression = _generate_binary_expression(
BinaryOperator.MUL, """A multiplication arithmetical expression."""
)
DivArithmeticExpression = _generate_binary_expression(
BinaryOperator.DIV, """A division arithmetical expression."""
)
ModArithmeticExpression = _generate_binary_expression(
BinaryOperator.MOD, """A modulo arithmetical expression."""
)
OrBitExpression = _generate_binary_expression(
BinaryOperator.OR, """An "or" bit expression."""
)
XorBitExpression = _generate_binary_expression(
BinaryOperator.XOR, """A "xor" bit expression."""
)
AndBitExpression = _generate_binary_expression(
BinaryOperator.AND, """An "and" bit expression."""
)
InExpression = _generate_binary_expression(BinaryOperator.IN, """An "in" expression.""")
InstanceofExpression = _generate_binary_expression(
BinaryOperator.INSTANCEOF, """An "instanceof" expression."""
)
SimpleAssignExpression = _generate_assignment_expression(
AssignmentOperator.ASSIGN, """An assignment done with operator ``=`` expression."""
)
AddAssignExpression = _generate_assignment_expression(
AssignmentOperator.ADD,
"""An addition assignment done with operator ``+=`` expression.""",
)
SubAssignExpression = _generate_assignment_expression(
AssignmentOperator.SUB,
"""A subtraction assignment done with operator ``-=`` expression.""",
)
MulAssignExpression = _generate_assignment_expression(
AssignmentOperator.MUL,
"""A multiplication assignment done with operator ``*=`` expression.""",
)
ModAssignExpression = _generate_assignment_expression(
AssignmentOperator.DIV,
"""A modulo assignment done with operator ``%=`` expression.""",
)
ShlAssignExpression = _generate_assignment_expression(
AssignmentOperator.SHL,
"""A left shift assignment done with operator ``<<=`` expression.""",
)
ShrAssignExpression = _generate_assignment_expression(
AssignmentOperator.SHR,
"""A right shift assignment done with operator ``>>=`` expression.""",
)
LogicShrAssignExpression = _generate_assignment_expression(
AssignmentOperator.SHR_LOGIC,
"""A logical right shift assignment done with operator ``>>>=`` expression.""",
)
OrAssignExpression = _generate_assignment_expression(
AssignmentOperator.OR,
"""A "bit or" assignment done with operator ``|=`` expression.""",
)
XorAssignExpression = _generate_assignment_expression(
AssignmentOperator.XOR,
"""A "bit xor" assignment done with operator ``^=`` expression.""",
)
AndAssignExpression = _generate_assignment_expression(
AssignmentOperator.AND,
"""A "bit and" assignment done with operator ``&=`` expression.""",
)
OrLogicExpression = _generate_logical_expression(
LogicalOperator.OR, """An "or" logical expression."""
)
AndLogicExpression = _generate_logical_expression(
LogicalOperator.AND, """An "and" logical expression."""
)
# "Property" block
class Property(Node):
"""A literal property in an object expression can have either a string or number as its `value`. Ordinary
property initializers have a `kind` value ``"init"``; getters and setters have the kind values ``"get"`` and
``"set"``, respectively. """
def __init__(
self,
loc: Optional[SourceLocation],
key: Union[Literal, Identifier],
value: Expression,
kind: PropKind,
method: bool,
shorthand: bool,
computed: bool,
):
super().__init__("Property", loc)
self.key = key
self.value = value
self.kind = kind
self.method = method
self.shorthand = shorthand
self.computed = computed
class AssignmentProperty(Property):
def __init__(
self,
loc: Optional[SourceLocation],
key: Union[Literal, Identifier],
value: Pattern,
shorthand: bool,
computed: bool,
):
super().__init__(loc, key, value, "init", False, shorthand, computed)
# "Patterns" block
#
# Destructuring binding and assignment are not part of ES5, but all binding positions accept Pattern
# to allow for destructuring in ES6. Nevertheless, for ES5, the only Pattern subtype is Identifier.
class Pattern(Node):
"""A pattern."""
def __init__(self, node_type: str, loc: Optional[SourceLocation]):
super().__init__(node_type, loc)
class ObjectPatternKeyValue(TypedDict):
key: Union[Literal, Identifier]
value: Pattern
class ObjectPattern(Pattern):
def __init__(
self, loc: Optional[SourceLocation], properties: List[ObjectPatternKeyValue]
):
super().__init__("ObjectPattern", loc)
self.properties = properties
class ArrayPattern(Pattern):
def __init__(
self, loc: Optional[SourceLocation], elements: List[Optional[Pattern]]
):
super().__init__("ArrayPattern", loc)
self.elements = elements