lower_regex.cpp

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#include "mim/plug/regex/phase/lower_regex.h"
 
#include <automaton/dfa.h>
#include <automaton/dfamin.h>
#include <automaton/nfa2dfa.h>
 
#include <mim/def.h>
 
#include <mim/plug/core/core.h>
#include <mim/plug/cps/cps.h>
#include <mim/plug/mem/mem.h>
 
#include "mim/plug/regex/autogen.h"
#include "mim/plug/regex/dfa2matcher.h"
#include "mim/plug/regex/regex2nfa.h"
 
// clang-format off
template<> struct std::formatter<automaton::DFA> : fe::ostream_formatter {};
template<> struct std::formatter<automaton::NFA> : fe::ostream_formatter {};
// clang-format on
 
namespace mim::plug::regex {
 
namespace {
const Def* wrap_in_cps2ds(const Def* callee) { return cps::op_cps2ds_dep(callee); }
} // namespace
 
const Def* LowerRegex::rewrite_imm_App(const App* app) {
    if (is_bootstrapping()) return RWPhase::rewrite_imm_App(app);
 
    auto callee = app->callee();
    if (Axm::isa<regex::conj>(callee) || Axm::isa<regex::disj>(callee) || Axm::isa<regex::not_>(callee)
        || Axm::isa<regex::neg_lookahead>(callee) || Axm::isa<regex::range>(callee) || Axm::isa<regex::any>(callee)
        || Axm::isa<quant>(callee) || Axm::isa<regex::empty>(callee)) {
        // The NFA is derived from the old callee's structure; only the argument needs rewriting.
        auto new_n = rewrite(app->arg());
        auto nfa   = regex2nfa(callee);
        DLOG("nfa: {}", *nfa);
 
        auto dfa = automaton::nfa2dfa(*nfa);
        DLOG("dfa: {}", *dfa);
 
        auto min_dfa = automaton::minimize_dfa(*dfa);
        return wrap_in_cps2ds(dfa2matcher(new_world(), *min_dfa, new_n));
    }
 
    return RWPhase::rewrite_imm_App(app);
}
 
} // namespace mim::plug::regex