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The Dolmen Parsing library

Architecture

This library provides functors to create parsers from a given representation of terms. This allows users to have a parser that directly outputs temrs in the desired form, without needing to translate the parser output into the specific AST used in a project.

Parsers (actually, the functors which generates parsers) typically takes four module arguments:

  • A representation of locations in files. This is used for reporting parsing and lexing errors, but also to attach to each expression parsed its location.
  • A representation of identifiers. In some languages, there are syntactic scopes, which are handled using namespaces for variable names. In order to not pollute the Term module with it, the namespaces are dealt with in this module separately.
  • A representation of terms. The functions in this module are used by the parser to build the various types, terms and formulas corresponding to the grammar of the input language. All functions of this module typically takes as first (optional) argument a location (of the type defined by the previous argument) so that is is possible to have locations for expressions.
  • A representation of top-level directives. Languages usually defines several top-level directives to more easily distinguish type definitions, axioms, lemma, theorems to prove, new assertions, or even sometimes direct commands for the solver (to set some options for instance). Again, the functions in this module usually have a first optional argument to set the location of the directives.

Some simple implementation of theses modules are provided in this library. See the next section for more information.

Example

Examples of how to use the parsers can be found in src/main.ml . As mentionned in the previous section, default implementation for the required functor arguments are provided, and can be used.

For instance, the following code instantiates a parser for the smtlib language and try to parse a file named "example.smt2" in the home of the current user:

module P =
  Dolmen.Smtlib2.Script.Latest.Make
    (Dolmen.Std.Loc)(Dolmen.Std.Id)(Dolmen.Std.Term)(Dolmen.Std.Statement)
    (Dolmen.Std.Extensions.Smtlib2)

let _, lazy_l = P.parse_all (`File "example.smt2")
let statements = Lazy.force lazy_l

For more examples, see the tutorial.