The scope language

This representation is the third in the compilation chain (see Architecture). Its main difference with the previous desugared representation is that inside a scope, the definitions are ordered according to their computational dependency order, and each definition is a Shared_ast.base_gexpr.EDefault tree instead of a flat list of rules.

Overloaded operators are also resolved during the translation to this representation.

The module describing the abstract syntax tree is:

• Scopelang.Ast Abstract syntax tree of the scope language

Printing helpers can be found in Scopelang.Print.

This intermediate representation corresponds to the scope language presented in the Catala formalization.

The Scopelang.From_desugared pass performs a few important transformation:

• the construction of the default trees (see Shared_ast.base_gexpr.EDefault) from the list of prioritized rules
• the resolution of overloads (using Shared_ast.Typing)
• wrapping of subscope arguments

The rest of the pass is performed on the scopelang ast:

• Scopelang.Dependency analyses inter-scope dependencies as well as the well-foundedness of types
• This is also where the main, full typing of the program takes place