The standard library Arg_Lexer api defines part of the yacc parser-generator suite.
The Arg_Lexer api source code is in src/app/yacc/lib/base.api. The above information is manually maintained and may contain errors.
api { package user_declarations : api { Token (X, Y); Source_Position; Semantic_Value; Arg;};; make_lexer : (Int -> String) -> user_declarations::Arg -> Void -> user_declarations::Token((user_declarations::Semantic_Value, user_declarations::Source_Position));};