1 files changed, 78 insertions, 0 deletions
diff --git a/src/sksl/lex/RegexNode.h b/src/sksl/lex/RegexNode.h
new file mode 100644
index 0000000000..e3aa65b3d1
--- /dev/null
+++ b/src/sksl/lex/RegexNode.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SKSL_REGEXNODE
+#define SKSL_REGEXNODE
+
+#include <string>
+#include <vector>
+
+struct NFA;
+
+/**
+ * Represents a node in the parse tree of a regular expression.
+ */
+struct RegexNode {
+    enum Kind {
+        kChar_Kind,
+        kCharset_Kind,
+        kConcat_Kind,
+        kDot_Kind,
+        kOr_Kind,
+        kPlus_Kind,
+        kRange_Kind,
+        kQuestion_Kind,
+        kStar_Kind
+    };
+
+    RegexNode(Kind kind)
+    : fKind(kind) {}
+
+    RegexNode(Kind kind, char payload)
+    : fKind(kind) {
+        fPayload.fChar = payload;
+    }
+
+    RegexNode(Kind kind, const char* children)
+    : fKind(kind) {
+        fPayload.fBool = false;
+        while (*children != '\0') {
+            fChildren.emplace_back(kChar_Kind, *children);
+            ++children;
+        }
+    }
+
+    RegexNode(Kind kind, RegexNode child)
+    : fKind(kind) {
+        fChildren.push_back(std::move(child));
+    }
+
+    RegexNode(Kind kind, RegexNode child1, RegexNode child2)
+    : fKind(kind) {
+        fChildren.push_back(std::move(child1));
+        fChildren.push_back(std::move(child2));
+    }
+
+    /**
+     * Creates NFA states for this node, with a successful match against this node resulting in a
+     * transition to all of the states in the accept vector.
+     */
+    std::vector<int> createStates(NFA* nfa, const std::vector<int>& accept) const;
+
+    std::string description() const;
+
+    Kind fKind;
+
+    union Payload {
+        char fChar;
+        bool fBool;
+    } fPayload;
+
+    std::vector<RegexNode> fChildren;
+};
+
+#endif