{0 Default calculus}

This representation is the fourth in the compilation chain
(see {{: index.html#architecture} Architecture}). Its main difference
with the previous {{: desugared.html} desugared representation} is that scopes
have been lowered into regular functions, and enums and structs have been
lowered to sum and product types. The default calculus can be later compiled
to a {{: lcalc.html} lambda calculus}.

The module describing the abstract syntax tree is {!module: Dcalc.Ast}.
Printing helpers can be found in {!module: Dcalc.Print}.
This intermediate representation corresponds to the default calculus
presented in the {{: https://arxiv.org/abs/2103.03198} Catala formalization}.

Related modules:

{!modules: Dcalc.Ast}

{1 Typing }

This representation is where the typing is performed. Indeed, {!module: Dcalc.Typing}
implements the classical {{: https://en.wikipedia.org/wiki/Hindley%E2%80%93Milner_type_system} W algorithm}
corresponding to a Hindley-Milner type system, without type constraints.

Related modules:

{!modules: Dcalc.Typing}

{1 Interpreter}

Since this representation is currently the last of the compilation chain,
an {!module: Dcalc.Interpreter} module is provided to match the execution
semantics of the default calculus.

Later, translations to a regular lambda calculus and/or a simple imperative
language are bound to be added.

Related modules:

{!modules: Dcalc.Interpreter}

{1 Optimizations}

Classical optimizations passes can be performed on the Dcalc AST: partial
evaluation, beta and iota-reduction, etc.

Related modules:

{!modules: Dcalc.Optimizations}