l0_backend_ordering::TypeOrdering class
compiler/stage1_py/l0_backend_ordering.py

Defined in module l0_backend_ordering (l0_backend_ordering.py).

Value-type dependency ordering and type-definition emission.

Public static attributes

static BackendState state

Protected functions

auto _extract_value_type_dependencies(self, Type typ) -> set[SymbolKey]
Extract type dependencies for VALUE fields only.
auto _build_type_dependency_graph(self) -> dict[SymbolKey, set[SymbolKey]]
Build dependency graph for type definitions.
auto _find_cycle_details(self, dict] graph[SymbolKey, set[SymbolKey], list unresolved[SymbolKey]) -> str
Find and format cycle details for error message.
auto _topological_sort(self, dict] graph[SymbolKey, set[SymbolKey]) -> list[SymbolKey]
Perform topological sort on type dependency graph using Kahn's algorithm.
auto _find_struct_decl(self, str module_name, str struct_name) -> StructDecl|None
Find the StructDecl AST node for a given struct.
auto _find_enum_decl(self, str module_name, str enum_name) -> EnumDecl|None
Find the EnumDecl AST node for a given enum.
auto _emit_type_definitions(self) -> None
Order value types and emit each definition with its optional wrapper.

Function documentation

set[SymbolKey] l0_backend_ordering::TypeOrdering::_extract_value_type_dependencies(self, Type typ) protected

Extract type dependencies for VALUE fields only.

Parameters
typ The type to extract dependencies from.
Returns Set of (module, name) tuples for types that must be defined first.

Value-type fields create dependencies (types must be fully defined). Pointer-type fields do NOT create dependencies (forward declarations suffice).

Examples:

  • StructType("main", "Point") -> {("main", "Point")}
  • EnumType("main", "Status") -> {("main", "Status")}
  • PointerType(StructType("main", "Node")) -> {} (no dependency, forward decl works)
  • NullableType(PointerType(...)) -> {} (pointer-optional, no dependency)
  • NullableType(BuiltinType("int")) -> {} (value-optional of builtin, no dependency)
  • NullableType(StructType("main", "Point")) -> {("main", "Point")} (value-optional of struct)
  • BuiltinType("int") -> {} (no dependency)

dict[SymbolKey, set[SymbolKey]] l0_backend_ordering::TypeOrdering::_build_type_dependency_graph(self) protected

Build dependency graph for type definitions.

Returns Dict mapping (module, type_name) -> Set of (module, type_name) dependencies.

A type X depends on type Y if X has a VALUE field of type Y. Pointer fields do NOT create dependencies (forward declarations handle them).

str l0_backend_ordering::TypeOrdering::_find_cycle_details(self, dict] graph[SymbolKey, set[SymbolKey], list unresolved[SymbolKey]) protected

Find and format cycle details for error message.

Parameters
graph The type dependency graph.
unresolved List of unresolved nodes.
Returns A string describing the detected cycle details.

list[SymbolKey] l0_backend_ordering::TypeOrdering::_topological_sort(self, dict] graph[SymbolKey, set[SymbolKey]) protected

Perform topological sort on type dependency graph using Kahn's algorithm.

Parameters
graph The type dependency graph.
Returns List of (module, type_name) in dependency order (dependencies first).
Exceptions
InternalCompilerError On cycles (value-type cycles are impossible in valid L0).

StructDecl|None l0_backend_ordering::TypeOrdering::_find_struct_decl(self, str module_name, str struct_name) protected

Find the StructDecl AST node for a given struct.

Parameters
module_name Name of the module.
struct_name Name of the struct.
Returns The StructDecl if found, otherwise None.

EnumDecl|None l0_backend_ordering::TypeOrdering::_find_enum_decl(self, str module_name, str enum_name) protected

Find the EnumDecl AST node for a given enum.

Parameters
module_name Name of the module.
enum_name Name of the enum.
Returns The EnumDecl if found, otherwise None.