Port and integrate the irregexp engine from V8

tests/language/regex/global_test.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'util.dart';
+import 'package:expect/expect.dart';
+
+void main() {
+  var str = "ABX X";
+  str = str.replaceAll(new RegExp(r"(\w)?X"), "c");
+  assertEquals("Ac c", str);
+
+  // Test zero-length matches.
+  str = "Als Gregor Samsa eines Morgens";
+  str = str.replaceAll(new RegExp(r"\b"), "/");
+  assertEquals("/Als/ /Gregor/ /Samsa/ /eines/ /Morgens/", str);
+
+  // Test zero-length matches that have non-zero-length sub-captures.
+  str = "It was a pleasure to burn.";
+  str = str.replaceAllMapped(new RegExp(r"(?=(\w+))\b"), (Match m) => m.group(1).length.toString());
+  assertEquals("2It 3was 1a 8pleasure 2to 4burn.", str);
+
+  // Test multiple captures.
+  str = "Try not. Do, or do not. There is no try.";
+  str = str.replaceAllMapped(new RegExp(r"(not?)|(do)|(try)", caseSensitive: false),
+                    (m) {
+                      if (m.group(1) != null) return "-";
+                      if (m.group(2) != null) return "+";
+                      if (m.group(3) != null) return "=";
+                    });
+  assertEquals("= -. +, or + -. There is - =.", str);
+
+  // Test multiple alternate captures.
+  str = "FOUR LEGS GOOD, TWO LEGS BAD!";
+  str = str.replaceAllMapped(new RegExp(r"(FOUR|TWO) LEGS (GOOD|BAD)"),
+                    (m) {
+                      if (m.group(1) == "FOUR") assertTrue(m.group(2) == "GOOD");
+                      if (m.group(1) == "TWO") assertTrue(m.group(2) == "BAD");
+                      return m.group(0).length - 10;
+                    });
+  assertEquals("4, 2!", str);
+
+
+  // The same tests with UC16.
+
+  //Test that an optional capture is cleared between two matches.
+  str = "AB\u1234 \u1234";
+  str = str.replaceAll(new RegExp(r"(\w)?\u1234"), "c");
+  assertEquals("Ac c", str);
+
+  // Test zero-length matches.
+  str = "Als \u2623\u2642 eines Morgens";
+  str = str.replaceAll(new RegExp(r"\b"), "/");
+
+  // Test zero-length matches that have non-zero-length sub-captures.
+  str = "It was a pleasure to \u70e7.";
+  str = str.replaceAllMapped(new RegExp(r"(?=(\w+))\b"), (m) => "${m.group(1).length}");
+  assertEquals("2It 3was 1a 8pleasure 2to \u70e7.", str);
+
+  // Test multiple captures.
+  str = "Try not. D\u26aa, or d\u26aa not. There is no try.";
+  str = str.replaceAllMapped(new RegExp(r"(not?)|(d\u26aa)|(try)", caseSensitive: false),
+                    (m) {
+                      if (m.group(1) != null) return "-";
+                      if (m.group(2) != null) return "+";
+                      if (m.group(3) != null) return "=";
+                    });
+  assertEquals("= -. +, or + -. There is - =.", str);
+
+  // Test multiple alternate captures.
+  str = "FOUR \u817f GOOD, TWO \u817f BAD!";
+  str = str.replaceAllMapped(new RegExp(r"(FOUR|TWO) \u817f (GOOD|BAD)"),
+                    (m) {
+                      if (m.group(1) == "FOUR") assertTrue(m.group(2) == "GOOD");
+                      if (m.group(1) == "TWO") assertTrue(m.group(2) == "BAD");
+                      return m.group(0).length - 7;
+                    });
+  assertEquals("4, 2!", str);
+
+  // Test capture that is a real substring.
+  str = "Beasts of England, beasts of Ireland";
+  str = str.replaceAll(new RegExp(r"(.*)"), '~');
+  assertEquals("~~", str);
+
+  // Test zero-length matches that have non-zero-length sub-captures that do not
+  // start at the match start position.
+  str = "up up up up";
+  str = str.replaceAllMapped(new RegExp(r"\b(?=u(p))"), (m) => "${m.group(1).length}");
+
+  assertEquals("1up 1up 1up 1up", str);
+
+
+  // Create regexp that has a *lot* of captures.
+  var re_string = "(a)";
+  for (var i = 0; i < 500; i++) {
+    re_string = "(" + re_string + ")";
+  }
+  re_string = re_string + "1";
+  // re_string = "(((...((a))...)))1"
+
+  var regexps = new List();
+  var last_match_expectations = new List();
+  var first_capture_expectations = new List();
+
+  // Atomic regexp.
+  regexps.add(new RegExp(r"a1"));
+  last_match_expectations.add("a1");
+  first_capture_expectations.add("");
+  // Small regexp (no capture);
+  regexps.add(new RegExp(r"\w1"));
+  last_match_expectations.add("a1");
+  first_capture_expectations.add("");
+  // Small regexp (one capture).
+  regexps.add(new RegExp(r"(a)1"));
+  last_match_expectations.add("a1");
+  first_capture_expectations.add("a");
+  // Large regexp (a lot of captures).
+  regexps.add(new RegExp(re_string));
+  last_match_expectations.add("a1");
+  first_capture_expectations.add("a");
+
+  dynamic test_replace(result_expectation,
+                        subject,
+                        regexp,
+                        replacement) {
+    for (var i = 0; i < regexps.length; i++) {
+      // Conduct tests.
+      assertEquals(result_expectation, subject.replaceAll(regexps[i], replacement));
+    }
+  }
+
+
+  // Test for different number of matches.
+  for (var m = 0; m < 33; m++) {
+    // Create string that matches m times.
+    var subject = "";
+    var test_1_expectation = "";
+    var test_2_expectation = "";
+    var test_3_expectation = (m == 0) ? null : new List();
+    for (var i = 0; i < m; i++) {
+      subject += "a11";
+      test_1_expectation += "x1";
+      test_2_expectation += "1";
+      test_3_expectation.add("a1");
+    }
+
+    // Test 1a: String.replace with string.
+    test_replace(test_1_expectation, subject, new RegExp(r"a1"), "x");
+
+    // Test 2a: String.replace with empty string.
+    test_replace(test_2_expectation, subject, new RegExp(r"a1"), "");
+  }
+
+
+  // Test String hashing (compiling regular expression includes hashing).
+  var crosscheck = "\x80";
+  for (var i = 0; i < 12; i++) crosscheck += crosscheck;
+    new RegExp(crosscheck);
+
+  var subject = "ascii~only~string~here~";
+  var replacement = "\x80";
+  var result = subject.replaceAll(new RegExp(r"~"), replacement);
+  for (var i = 0; i < 5; i++) result += result;
+    new RegExp(result);
+}