Revert "Revert "Initial checkin of SkSL lexical analyzer generator (not actually in use yet).""
This reverts commit 3ed4781ee1bd5af9b3ee2623e5356e86ce36e812.
Bug: skia:
Change-Id: If0de7ca17c4da8000d3526a73b71be6ee34ce060
Reviewed-on: https://skia-review.googlesource.com/43561
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/src/sksl/lex/NFA.cpp b/src/sksl/lex/NFA.cpp
new file mode 100644
index 0000000..d1eb749
--- /dev/null
+++ b/src/sksl/lex/NFA.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "NFA.h"
+
+int NFA::match(std::string s) const {
+ std::vector<int> states = fStartStates;
+ for (size_t i = 0; i < s.size(); ++i) {
+ std::vector<int> next;
+ for (int id : states) {
+ if (fStates[id].accept(s[i])) {
+ for (int nextId : fStates[id].fNext) {
+ if (fStates[nextId].fKind != NFAState::kRemapped_Kind) {
+ next.push_back(nextId);
+ } else {
+ next.insert(next.end(), fStates[nextId].fData.begin(),
+ fStates[nextId].fData.end());
+ }
+ }
+ }
+ }
+ if (!next.size()) {
+ return -1;
+ }
+ states = next;
+ }
+ int accept = -1;
+ for (int id : states) {
+ if (fStates[id].fKind == NFAState::kAccept_Kind) {
+ int result = fStates[id].fData[0];
+ if (accept == -1 || result < accept) {
+ accept = result;
+ }
+ }
+ }
+ return accept;
+}