lfe_struct.erl - Struct Runtime Support

Purpose: Runtime support functions for struct operations (map-based records).

Location: src/lfe_struct.erl Size: 33 LOC, 988B

Module Classification: Library, runtime support

This is the smallest module in the codebase.

Public API

new(Module) -> Struct
new(Module, Fields) -> Struct
is(Struct, Module) -> boolean()
fetch(Struct, Module, Field) -> Value

Struct operations. Located at lfe_struct.erl:25-33.

Struct Format

Structs are maps with __struct__ key:

#{__struct__ => ModuleName,
  field1 => Value1,
  field2 => Value2}

Operations

Create:

Struct = lfe_struct:new(person, [{name, "Alice"}, {age, 30}])
% → #{__struct__ => person, name => "Alice", age => 30}

Type Check:

lfe_struct:is(Struct, person)  % → true
lfe_struct:is(Struct, other)   % → false

Field Access:

lfe_struct:fetch(Struct, person, name)  % → "Alice"

Dependencies

• maps (Erlang stdlib)

Used By

• lfe_macro_struct - Macro expansion
• lfe_eval - Struct evaluation
• User code - Struct operations

Special Considerations

Elixir-Inspired: Borrows from Elixir's struct concept.

Map-Based: More flexible than records (tuples).

Type Tagged: __struct__ key identifies struct type.