internal/

Package ast holds the abstract syntax tree node types for the regular expression grammar.

Package charset classifies a single Unicode code point against the property names this engine recognises for the \p{…} / \P{…} construct.

Package compile lowers a syntax AST into the flat instruction program that the backtracking VM executes.

Package syntax holds the scanner and recursive-descent parser that turn an Onigmo/Ruby regular-expression pattern into an abstract syntax tree (the node types live in the sibling ast package).

Package vm executes a compiled program against an input using explicit backtracking with greedy, leftmost-first semantics (as in Ruby/Onigmo).