JezK

Edit File: switch.js

// Copyright 2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Flags: --allow-natives-syntax

function f0() {
  switch (0) {
    // switch deliberately left empty
  }
}

f0();  // no errors

function f1(x) {
  switch (x) {
    default:      return "f1";
  }
  return "foo";
}

assertEquals("f1", f1(0), "default-switch.0");
assertEquals("f1", f1(1), "default-switch.1");

function f2(x) {
  var r;
  switch (x) {
    case 0:
      r = "zero";
      break;
    case 1:
      r = "one";
      break;
    case 2:
      r = "two";
      break;
    case 3:
      r = "three";
      break;
    default:
      r = "default";
  }
  return r;
}

assertEquals("zero", f2(0), "0-1-switch.0");
assertEquals("one", f2(1), "0-1-switch.1");
assertEquals("default", f2(7), "0-1-switch.2");
assertEquals("default", f2(-1), "0-1-switch.-1");
assertEquals("default", f2(NaN), "0-1-switch.NaN");
assertEquals("default", f2(Math.pow(2,34)), "0-1-switch.largeNum");
assertEquals("default", f2("0"), "0-1-switch.string");
assertEquals("default", f2(false), "0-1-switch.bool");
assertEquals("default", f2(null), "0-1-switch.null");
assertEquals("default", f2(undefined), "0-1-switch.undef");
assertEquals("default", f2(new Number(2)), "0-1-switch.undef");
assertEquals("default", f2({valueOf: function(){return 2; }}), "0-1-switch.obj");

function f3(x, c) {
  var r = 0;
  switch (x) {
    default:
      r = "default";
      break;
    case  c:
      r = "value is c = " + c;
      break;
    case  2:
      r = "two";
      break;
    case -5:
      r = "minus 5";
      break;
    case  9:
      r = "nine";
      break;
  }
  return r;
}

assertEquals("two", f3(2,0), "value-switch.2-0");
assertEquals("minus 5", f3(-5,0), "value-switch.-5-0");
assertEquals("nine", f3(9,0), "value-switch.9-0");
assertEquals("value is c = 0", f3(0,0), "value-switch.0-0");
assertEquals("value is c = 2", f3(2,2), "value-switch.2-2");
assertEquals("default", f3(7,0), "value-switch.7-0");

function f4(x) {
  switch(x) {
    case 0:
      x++;
    default:
      x++;
    case 2:
      x++;
  }
  return x;
}

assertEquals(3, f4(0), "fallthrough-switch.0");
assertEquals(3, f4(1), "fallthrough-switch.1");
assertEquals(3, f4(2), "fallthrough-switch.2");
assertEquals(5, f4(3), "fallthrough-switch.3");

function f4_string(tag, x) {
  switch(tag) {
    case 'zero':
      x++;
    case 'two':
      x++;
  }
  return x;
}

// Symbols
assertEquals(2, f4_string('zero', 0), "fallthrough-string-switch.0");
assertEquals(1, f4_string('one', 1), "fallthrough-string-switch.1");
assertEquals(3, f4_string('two', 2), "fallthrough-string-switch.2");

// Strings
assertEquals(2, f4_string('_zero'.slice(1), 0), "fallthrough-string-switch.3");
assertEquals(1, f4_string('_one'.slice(1), 1), "fallthrough-string-switch.4");
assertEquals(3, f4_string('_two'.slice(1), 2), "fallthrough-string-switch.5");

// Oddball
assertEquals(3, f4_string(null, 3), "fallthrough-string-switch.6");

// Test for regression
function regress_string(value) {
  var json = 1;
  switch (typeof value) {
    case 'object':
      break;

default:

}
  return json;
};
assertEquals(1, regress_string('object'), 'regression-string');

function f5(x) {
  switch(x) {
     case -2: return true;
     case -1: return false;
     case 0: return true;
     case 2: return false;
     default: return 42;
  }
}

assertTrue(f5(-2), "negcase.-2");
assertFalse(f5(-1), "negcase.-1");
assertTrue(f5(0), "negcase.-0");
assertEquals(42, f5(1), "negcase.1");
assertFalse(f5(2), "negcase.2");

assertEquals(190, f6(20), "largeSwitch.20");
assertEquals(2016, f6(64), "largeSwitch.64");
assertEquals(4032, f6(128), "largeSwitch.128");
assertEquals(4222, f6(148), "largeSwitch.148");

assertEquals("default", f7(0.1), "0-1-switch.double-0.1");
assertEquals("0", f7(-0), "0-1-switch.double-neg0");
assertEquals("MaxSmi", f7((1<<30)-1), "0-1-switch.maxsmi");
assertEquals("MinSmi", f7(-(1<<30)), "0-1-switch.minsmi");
assertEquals("default", f7(1<<30), "0-1-switch.maxsmi++");
assertEquals("default", f7(-(1<<30)-1), "0-1-switch.minsmi--");
assertEquals("A", f7((170/16)-(170%16/16)), "0-1-switch.heapnum");

assertEquals(verylong_size * 2 + 1, verylong());

// Function-with-switch generator
var test_id = 0,
    clause_values = {
      string: ['abc', 'def', 'ghi', 'jkl'],
      smi: [1, 2, 3, 4],
      mixed: ['abc', 1, 'def', 2, 'ghi', 3, 'jkl', 4]
    };

function switch_gen(clause_type, feedback, optimize) {
  var values = clause_values[clause_type];

if (optimize) %OptimizeFunctionOnNextCall(fn);

return fn;
  };

return opt(new Function(
      'tag',
      '"' + (test_id++) + '";' +
      'switch(tag) {' +
      values.map(function(value) {
        return 'case ' + JSON.stringify(value) + ': return' +
               JSON.stringify('ok-' + value);
      }).join(';') +
      '}'
  ));
};

function test_switch(clause_type, test_type, feedback, optimize) {
  var pairs = [],
      fn = switch_gen(clause_type, feedback, optimize);

if (Array.isArray(test_type)) {
    pairs = test_type.map(function(v) {
      return {
        value: v,
        expected: 'ok-' + v
      };
    });
  } else if (test_type === 'symbols') {
    pairs = clause_values.string.map(function(v) {
      return {
        value: v,
        expected: clause_type !== 'smi' ? 'ok-' + v : undefined
      };
    });
  } else if (test_type === 'strings') {
    pairs = clause_values.string.map(function(v) {
      return {
        value: ('%%' + v).slice(2),
        expected: clause_type !== 'smi' ? 'ok-' + v : undefined
      };
    });
  } else if (test_type === 'oddball') {
    pairs = [
      { value: null, expected: undefined },
      { value: NaN, expected: undefined },
      { value: undefined, expected: undefined }
    ];
  } else if (test_type === 'smi') {
    pairs = clause_values.smi.map(function(v) {
      return {
        value: v,
        expected: clause_type !== 'string' ? 'ok-' + v : undefined
      };
    });
  } else if (test_type === 'heapnum') {
    pairs = clause_values.smi.map(function(v) {
      return {
        value: ((v * 17)/16) - ((v*17)%16/16),
        expected: clause_type !== 'string' ? 'ok-' + v : undefined
      };
    });
  }

pairs.forEach(function(pair) {
    assertEquals(fn(pair.value), pair.expected);
  });
};

// test_switch(clause_type, test_type, feedback, optimize);

function test_switches(opt) {
  var test_types = ['symbols', 'strings', 'oddball', 'smi', 'heapnum'];

function test(clause_type) {
    var values = clause_values[clause_type];

test_types.forEach(function(test_type) {
      test_switch(clause_type, test_type, 'all', opt);
      test_switch(clause_type, test_type, 'none', opt);

// Targeting specific clause feedback
      values.forEach(function(value) {
        test_switch(clause_type, test_type, [value], value, opt);
        test_switch(clause_type, test_type, value, value, opt);
      });
    });
  };

test('string');
  test('smi');
  test('mixed');
};

test_switches(false);
test_switches(true);

JezK

Edit File: switch.js

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