Blockly.Lua[''] = function()

in generators/lua/lists.js [123:199]
61 lines of code
24 McCabe index (conditional complexity)

Blockly.Lua['lists_getIndex'] = function(block) {
  // Get element at index.
  // Note: Until January 2013 this block did not have MODE or WHERE inputs.
  var mode = block.getFieldValue('MODE') || 'GET';
  var where = block.getFieldValue('WHERE') || 'FROM_START';
  var list = Blockly.Lua.valueToCode(block, 'VALUE', Blockly.Lua.ORDER_HIGH) ||
      '({})';
  var getIndex_ = Blockly.Lua.lists.getIndex_;

  // If `list` would be evaluated more than once (which is the case for LAST,
  // FROM_END, and RANDOM) and is non-trivial, make sure to access it only once.
  if ((where == 'LAST' || where == 'FROM_END' || where == 'RANDOM') &&
      !list.match(/^\w+$/)) {
    // `list` is an expression, so we may not evaluate it more than once.
    if (mode == 'REMOVE') {
      // We can use multiple statements.
      var atOrder = (where == 'FROM_END') ? Blockly.Lua.ORDER_ADDITIVE :
          Blockly.Lua.ORDER_NONE;
      var at = Blockly.Lua.valueToCode(block, 'AT', atOrder) || '1';
      var listVar = Blockly.Lua.nameDB_.getDistinctName(
          'tmp_list', Blockly.VARIABLE_CATEGORY_NAME);
      at = getIndex_(listVar, where, at);
      var code = listVar + ' = ' + list + '\n' +
          'table.remove(' + listVar + ', ' + at + ')\n';
      return code;
    } else {
      // We need to create a procedure to avoid reevaluating values.
      var at = Blockly.Lua.valueToCode(block, 'AT', Blockly.Lua.ORDER_NONE) ||
          '1';
      if (mode == 'GET') {
        var functionName = Blockly.Lua.provideFunction_(
            'list_get_' + where.toLowerCase(),
            ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(t' +
                // The value for 'FROM_END' and'FROM_START' depends on `at` so
                // we add it as a parameter.
                ((where == 'FROM_END' || where == 'FROM_START') ?
                    ', at)' : ')'),
             '  return t[' + getIndex_('t', where, 'at') + ']',
             'end']);
      } else {  //  mode == 'GET_REMOVE'
        var functionName = Blockly.Lua.provideFunction_(
            'list_remove_' + where.toLowerCase(),
            ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(t' +
                // The value for 'FROM_END' and'FROM_START' depends on `at` so
                // we add it as a parameter.
                ((where == 'FROM_END' || where == 'FROM_START') ?
                    ', at)' : ')'),
             '  return table.remove(t, ' + getIndex_('t', where, 'at') + ')',
             'end']);
      }
      var code = functionName + '(' + list +
          // The value for 'FROM_END' and 'FROM_START' depends on `at` so we
          // pass it.
          ((where == 'FROM_END' || where == 'FROM_START') ? ', ' + at : '') +
          ')';
      return [code, Blockly.Lua.ORDER_HIGH];
    }
  } else {
    // Either `list` is a simple variable, or we only need to refer to `list`
    // once.
    var atOrder = (mode == 'GET' && where == 'FROM_END') ?
        Blockly.Lua.ORDER_ADDITIVE : Blockly.Lua.ORDER_NONE;
    var at = Blockly.Lua.valueToCode(block, 'AT', atOrder) || '1';
    at = getIndex_(list, where, at);
    if (mode == 'GET') {
      var code = list + '[' + at + ']';
      return [code, Blockly.Lua.ORDER_HIGH];
    } else {
      var code = 'table.remove(' + list + ', ' + at + ')';
      if (mode == 'GET_REMOVE') {
        return [code, Blockly.Lua.ORDER_HIGH];
      } else {  // `mode` == 'REMOVE'
        return code + '\n';
      }
    }
  }
};