Blockly.JavaScript[''] = function()

in generators/javascript/math.js [221:349]
123 lines of code
17 McCabe index (conditional complexity)

Blockly.JavaScript['math_on_list'] = function(block) {
  // Math functions for lists.
  var func = block.getFieldValue('OP');
  var list, code;
  switch (func) {
    case 'SUM':
      list = Blockly.JavaScript.valueToCode(block, 'LIST',
          Blockly.JavaScript.ORDER_MEMBER) || '[]';
      code = list + '.reduce(function(x, y) {return x + y;})';
      break;
    case 'MIN':
      list = Blockly.JavaScript.valueToCode(block, 'LIST',
          Blockly.JavaScript.ORDER_NONE) || '[]';
      code = 'Math.min.apply(null, ' + list + ')';
      break;
    case 'MAX':
      list = Blockly.JavaScript.valueToCode(block, 'LIST',
          Blockly.JavaScript.ORDER_NONE) || '[]';
      code = 'Math.max.apply(null, ' + list + ')';
      break;
    case 'AVERAGE':
      // mathMean([null,null,1,3]) == 2.0.
      var functionName = Blockly.JavaScript.provideFunction_(
          'mathMean',
          ['function ' + Blockly.JavaScript.FUNCTION_NAME_PLACEHOLDER_ +
              '(myList) {',
            '  return myList.reduce(function(x, y) {return x + y;}) / ' +
                  'myList.length;',
            '}']);
      list = Blockly.JavaScript.valueToCode(block, 'LIST',
          Blockly.JavaScript.ORDER_NONE) || '[]';
      code = functionName + '(' + list + ')';
      break;
    case 'MEDIAN':
      // mathMedian([null,null,1,3]) == 2.0.
      var functionName = Blockly.JavaScript.provideFunction_(
          'mathMedian',
          ['function ' + Blockly.JavaScript.FUNCTION_NAME_PLACEHOLDER_ +
              '(myList) {',
            '  var localList = myList.filter(function (x) ' +
              '{return typeof x == \'number\';});',
            '  if (!localList.length) return null;',
            '  localList.sort(function(a, b) {return b - a;});',
            '  if (localList.length % 2 == 0) {',
            '    return (localList[localList.length / 2 - 1] + ' +
              'localList[localList.length / 2]) / 2;',
            '  } else {',
            '    return localList[(localList.length - 1) / 2];',
            '  }',
            '}']);
      list = Blockly.JavaScript.valueToCode(block, 'LIST',
          Blockly.JavaScript.ORDER_NONE) || '[]';
      code = functionName + '(' + list + ')';
      break;
    case 'MODE':
      // As a list of numbers can contain more than one mode,
      // the returned result is provided as an array.
      // Mode of [3, 'x', 'x', 1, 1, 2, '3'] -> ['x', 1].
      var functionName = Blockly.JavaScript.provideFunction_(
          'mathModes',
          ['function ' + Blockly.JavaScript.FUNCTION_NAME_PLACEHOLDER_ +
              '(values) {',
            '  var modes = [];',
            '  var counts = [];',
            '  var maxCount = 0;',
            '  for (var i = 0; i < values.length; i++) {',
            '    var value = values[i];',
            '    var found = false;',
            '    var thisCount;',
            '    for (var j = 0; j < counts.length; j++) {',
            '      if (counts[j][0] === value) {',
            '        thisCount = ++counts[j][1];',
            '        found = true;',
            '        break;',
            '      }',
            '    }',
            '    if (!found) {',
            '      counts.push([value, 1]);',
            '      thisCount = 1;',
            '    }',
            '    maxCount = Math.max(thisCount, maxCount);',
            '  }',
            '  for (var j = 0; j < counts.length; j++) {',
            '    if (counts[j][1] == maxCount) {',
            '        modes.push(counts[j][0]);',
            '    }',
            '  }',
            '  return modes;',
            '}']);
      list = Blockly.JavaScript.valueToCode(block, 'LIST',
          Blockly.JavaScript.ORDER_NONE) || '[]';
      code = functionName + '(' + list + ')';
      break;
    case 'STD_DEV':
      var functionName = Blockly.JavaScript.provideFunction_(
          'mathStandardDeviation',
          ['function ' + Blockly.JavaScript.FUNCTION_NAME_PLACEHOLDER_ +
              '(numbers) {',
            '  var n = numbers.length;',
            '  if (!n) return null;',
            '  var mean = numbers.reduce(function(x, y) {return x + y;}) / n;',
            '  var variance = 0;',
            '  for (var j = 0; j < n; j++) {',
            '    variance += Math.pow(numbers[j] - mean, 2);',
            '  }',
            '  variance = variance / n;',
            '  return Math.sqrt(variance);',
            '}']);
      list = Blockly.JavaScript.valueToCode(block, 'LIST',
          Blockly.JavaScript.ORDER_NONE) || '[]';
      code = functionName + '(' + list + ')';
      break;
    case 'RANDOM':
      var functionName = Blockly.JavaScript.provideFunction_(
          'mathRandomList',
          ['function ' + Blockly.JavaScript.FUNCTION_NAME_PLACEHOLDER_ +
              '(list) {',
            '  var x = Math.floor(Math.random() * list.length);',
            '  return list[x];',
            '}']);
      list = Blockly.JavaScript.valueToCode(block, 'LIST',
          Blockly.JavaScript.ORDER_NONE) || '[]';
      code = functionName + '(' + list + ')';
      break;
    default:
      throw Error('Unknown operator: ' + func);
  }
  return [code, Blockly.JavaScript.ORDER_FUNCTION_CALL];
};