lfe_macro_export.erl - Export Macro Processor

Purpose: Handle macro exports between modules in the same file.

Location: src/lfe_macro_export.erl Size: 288 LOC, 8.8KB

Module Classification: Compiler support, macro system

Public API

export(Modules, Env, State) -> {ok, Env, State}
                               | {error, Errors, Warnings, State}

Process macro exports across modules. Located at lfe_macro_export.erl:42-47.

Export Mechanism

Syntax:

(defmodule foo
  (export-macro when-test my-cond))

(defmodule bar
  (import-macro foo when-test))

Process:

1. Collect all export-macro declarations
2. Collect all import-macro declarations
3. For each import, copy macro binding from exporting module to importing module
4. Validate: exported macros must exist, no circular dependencies

Implementation (lfe_macro_export.erl:67-158):

collect_exports(Modules) ->
    % Build map: ModuleName → ExportedMacros
    ...

collect_imports(Modules) ->
    % Build map: ModuleName → ImportedMacros
    ...

validate_imports(Imports, Exports) ->
    % Check all imports have corresponding exports
    ...

merge_macros(FromEnv, ToEnv, MacroNames) ->
    % Copy macro bindings between environments
    ...

Dependencies

• lfe_env - Environment operations
• lfe_lib - Utilities
• lists, orddict

Used By

• lfe_comp - Called during compilation if multi-module file

Special Considerations

Scope: Only works within a single file. Macros cannot be exported across file boundaries (by design - macros are compile-time only).

Order Independence: Modules can import macros from modules defined later in the same file.