Provisional API: This reference documents current compiler behavior. Compatibility is not yet promised.

`src/ast.x`

Shared helpers for x2c compiler AST nodes.

Functions

Function	Summary
`ast_changes_left_operand`	Returns whether `op` writes its left operand.
`ast_contains_head`	Returns whether any list under `value` has `kind` as its head.
`binding_identity_new`	Constructs a `(binding identity spelling)` node.
`binding_identity_spelling`	Returns a valid binding node’s source spelling, or `NULL`.
`binding_identity_try_parts`	Extracts a valid `(binding positive-integer string)` node.
`Ast.never_returns`	Returns whether control cannot flow out the bottom of `ast`.
`Ast.rewrite_children`	Applies `per_child` to each `List` child of `ast` and returns the node rebuilt from the results; non-list children pass through.
`Symbol.compound_assignment`	Returns the compound assignment for a binary operator, or zero.
`Symbol.compound_operator`	Returns the binary operator computed by a compound assignment, or zero.
`Symbol.is_assignment_op`	Returns whether `op` is plain or compound assignment.

Functions

ast_changes_left_operand

int ast_changes_left_operand(Symbol op)

Returns whether op writes its left operand.

Source: src/ast.x:90

ast_contains_head

int ast_contains_head(Var value, Symbol kind)

Returns whether any list under value has kind as its head. The worklist keeps deeply nested operator chains off the C stack.

Source: src/ast.x:95

binding_identity_new

List binding_identity_new(int identity, String spelling)

Constructs a (binding identity spelling) node. The caller must supply a positive compiler-issued identity.

Source: src/ast.x:38

binding_identity_spelling

String binding_identity_spelling(List binding)

Returns a valid binding node’s source spelling, or NULL.

Source: src/ast.x:57

binding_identity_try_parts

int binding_identity_try_parts(List binding, int *identity, String *spelling)

Extracts a valid (binding positive-integer string) node. Returns one on success and writes only non-NULL outputs; failure returns zero without changing either output.

Source: src/ast.x:45

Returns whether control cannot flow out the bottom of ast. Recognized terminals are shared non-returning raises, native termination calls, and blocks ending in either one when the block contains no return. Generation uses this fact to mark the enclosing function _Noreturn.

Source: src/ast.x:184

Ast.rewrite_children

Ast Ast.rewrite_children(Ast ast, Func per_child)

Applies per_child to each List child of ast and returns the node rebuilt from the results; non-list children pass through. When no child changed, the scratch storage is freed and ast itself returns, so the fixed-point transform driver can compare unchanged-node identity.

Source: src/ast.x:114

`Symbol`

Symbol.compound_assignment

Symbol Symbol.compound_assignment(Symbol op)

Returns the compound assignment for a binary operator, or zero.

Source: src/ast.x:83

Symbol.compound_operator

Symbol Symbol.compound_operator(Symbol op)

Returns the binary operator computed by a compound assignment, or zero.

Source: src/ast.x:80

Symbol.is_assignment_op

int Symbol.is_assignment_op(Symbol op)

Returns whether op is plain or compound assignment.

Source: src/ast.x:86

Public types

Type	Kind	Summary
`Ast`	alias	Represents one compiler AST node as a canonical immutable `List`.
`AstPos`	enum	Names the syntactic position in which an AST is parsed or bound.

Ast

typedef List Ast

Represents one compiler AST node as a canonical immutable List. NULL denotes no node, and nonempty nodes have the canonical List-pool lifetime.

Source: src/ast.x:13

AstPos

typedef enum AstPos { AST_UNIT, AST_BLOCK, AST_FIELD, AST_ENUMERATOR, AST_MAP_ENTRY, AST_STATEMENT, AST_EXPRESSION } AstPos

Names the syntactic position in which an AST is parsed or bound.

Source: src/ast.x:16

Design notes

Keeps sequence placement in one place. Simple fixed-shape nodes remain direct immutable Lists.

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