Include RE2 library

third_party/re2/re2/testing/required_prefix_test.cc

+// Copyright 2009 The RE2 Authors.  All Rights Reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "util/test.h"
+#include "re2/regexp.h"
+
+namespace re2 {
+
+struct PrefixTest {
+  const char* regexp;
+  bool return_value;
+  const char* prefix;
+  bool foldcase;
+  const char* suffix;
+};
+
+static PrefixTest tests[] = {
+  // If the regexp is missing a ^, there's no required prefix.
+  { "abc", false },
+  { "", false },
+  { "(?m)^", false },
+
+  // If the regexp immediately goes into
+  // something not a literal match, there's no required prefix.
+  { "^(abc)", false },
+  { "^a*",  false },
+
+  // Otherwise, it should work.
+  { "^abc$", true, "abc", false, "(?-m:$)" },
+  { "^abc", "true", "abc", false, "" },
+  { "^(?i)abc", true, "abc", true, "" },
+  { "^abcd*", true, "abc", false, "d*" },
+  { "^[Aa][Bb]cd*", true, "ab", true, "cd*" },
+  { "^ab[Cc]d*", true, "ab", false, "[Cc]d*" },
+  { "^☺abc", true, "☺abc", false, "" },
+};
+
+TEST(RequiredPrefix, SimpleTests) {
+  for (int i = 0; i < arraysize(tests); i++) {
+    const PrefixTest& t = tests[i];
+    for (int j = 0; j < 2; j++) {
+      Regexp::ParseFlags flags = Regexp::LikePerl;
+      if (j == 0)
+        flags = flags | Regexp::Latin1;
+      Regexp* re = Regexp::Parse(t.regexp, flags, NULL);
+      CHECK(re) << " " << t.regexp;
+      string p;
+      bool f = false;
+      Regexp* s = NULL;
+      CHECK_EQ(t.return_value, re->RequiredPrefix(&p, &f, &s))
+        << " " << t.regexp << " " << (j==0 ? "latin1" : "utf") << " " << re->Dump();
+      if (t.return_value) {
+        CHECK_EQ(p, string(t.prefix))
+          << " " << t.regexp << " " << (j==0 ? "latin1" : "utf");
+        CHECK_EQ(f, t.foldcase)
+          << " " << t.regexp << " " << (j==0 ? "latin1" : "utf");
+        CHECK_EQ(s->ToString(), string(t.suffix))
+          << " " << t.regexp << " " << (j==0 ? "latin1" : "utf");
+        s->Decref();
+      }
+      re->Decref();
+    }
+  }
+}
+
+}  // namespace re2