generators/dart/lists.js
/**
* @license
* Visual Blocks Language
*
* Copyright 2014 Google Inc.
* https://blockly.googlecode.com/
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview Generating Dart for list blocks.
* @author fraser@google.com (Neil Fraser)
*/
'use strict';
goog.provide('Blockly.Dart.lists');
goog.require('Blockly.Dart');
Blockly.Dart.addReservedWords('Math');
Blockly.Dart['lists_create_empty'] = function(block) {
// Create an empty list.
return ['[]', Blockly.Dart.ORDER_ATOMIC];
};
Blockly.Dart['lists_create_with'] = function(block) {
// Create a list with any number of elements of any type.
var code = new Array(block.itemCount_);
for (var n = 0; n < block.itemCount_; n++) {
code[n] = Blockly.Dart.valueToCode(block, 'ADD' + n,
Blockly.Dart.ORDER_NONE) || 'null';
}
code = '[' + code.join(', ') + ']';
return [code, Blockly.Dart.ORDER_ATOMIC];
};
Blockly.Dart['lists_repeat'] = function(block) {
// Create a list with one element repeated.
var argument0 = Blockly.Dart.valueToCode(block, 'ITEM',
Blockly.Dart.ORDER_NONE) || 'null';
var argument1 = Blockly.Dart.valueToCode(block, 'NUM',
Blockly.Dart.ORDER_NONE) || '0';
var code = 'new List.filled(' + argument1 + ', ' + argument0 + ')';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
};
Blockly.Dart['lists_length'] = function(block) {
// List length.
var argument0 = Blockly.Dart.valueToCode(block, 'VALUE',
Blockly.Dart.ORDER_UNARY_POSTFIX) || '[]';
return [argument0 + '.length', Blockly.Dart.ORDER_UNARY_POSTFIX];
};
Blockly.Dart['lists_isEmpty'] = function(block) {
// Is the list empty?
var argument0 = Blockly.Dart.valueToCode(block, 'VALUE',
Blockly.Dart.ORDER_UNARY_POSTFIX) || '[]';
return [argument0 + '.isEmpty', Blockly.Dart.ORDER_UNARY_POSTFIX];
};
Blockly.Dart['lists_indexOf'] = function(block) {
// Find an item in the list.
var operator = block.getFieldValue('END') == 'FIRST' ?
'indexOf' : 'lastIndexOf';
var argument0 = Blockly.Dart.valueToCode(block, 'FIND',
Blockly.Dart.ORDER_NONE) || '\'\'';
var argument1 = Blockly.Dart.valueToCode(block, 'VALUE',
Blockly.Dart.ORDER_UNARY_POSTFIX) || '[]';
var code = argument1 + '.' + operator + '(' + argument0 + ') + 1';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
};
Blockly.Dart['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 at = Blockly.Dart.valueToCode(block, 'AT',
Blockly.Dart.ORDER_UNARY_PREFIX) || '1';
var list = Blockly.Dart.valueToCode(block, 'VALUE',
Blockly.Dart.ORDER_UNARY_POSTFIX) || '[]';
if (where == 'FIRST') {
if (mode == 'GET') {
var code = list + '.first';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'GET_REMOVE') {
var code = list + '.removeAt(0)';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'REMOVE') {
return list + '.removeAt(0);\n';
}
} else if (where == 'LAST') {
if (mode == 'GET') {
var code = list + '.last';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'GET_REMOVE') {
var code = list + '.removeLast()';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'REMOVE') {
return list + '.removeLast();\n';
}
} else if (where == 'FROM_START') {
// Blockly uses one-based indicies.
if (Blockly.isNumber(at)) {
// If the index is a naked number, decrement it right now.
at = parseInt(at, 10) - 1;
} else {
// If the index is dynamic, decrement it in code.
at += ' - 1';
}
if (mode == 'GET') {
var code = list + '[' + at + ']';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'GET_REMOVE') {
var code = list + '.removeAt(' + at + ')';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'REMOVE') {
return list + '.removeAt(' + at + ');\n';
}
} else if (where == 'FROM_END') {
if (mode == 'GET') {
var functionName = Blockly.Dart.provideFunction_(
'lists_get_from_end',
[ 'dynamic ' + Blockly.Dart.FUNCTION_NAME_PLACEHOLDER_ +
'(List myList, num x) {',
' x = myList.length - x;',
' return myList.removeAt(x);',
'}']);
code = functionName + '(' + list + ', ' + at + ')';
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'GET_REMOVE' || mode == 'REMOVE') {
var functionName = Blockly.Dart.provideFunction_(
'lists_remove_from_end',
[ 'dynamic ' + Blockly.Dart.FUNCTION_NAME_PLACEHOLDER_ +
'(List myList, num x) {',
' x = myList.length - x;',
' return myList.removeAt(x);',
'}']);
code = functionName + '(' + list + ', ' + at + ')';
if (mode == 'GET_REMOVE') {
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'REMOVE') {
return code + ';\n';
}
}
} else if (where == 'RANDOM') {
Blockly.Dart.definitions_['import_dart_math'] =
'import \'dart:math\' as Math;';
var functionName = Blockly.Dart.provideFunction_(
'lists_get_random_item',
[ 'dynamic ' + Blockly.Dart.FUNCTION_NAME_PLACEHOLDER_ +
'(List myList, bool remove) {',
' int x = new Math.Random().nextInt(myList.length);',
' if (remove) {',
' return myList.removeAt(x);',
' } else {',
' return myList[x];',
' }',
'}']);
code = functionName + '(' + list + ', ' + (mode != 'GET') + ')';
if (mode == 'GET' || mode == 'GET_REMOVE') {
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
} else if (mode == 'REMOVE') {
return code + ';\n';
}
}
throw 'Unhandled combination (lists_getIndex).';
};
Blockly.Dart['lists_setIndex'] = function(block) {
// Set element at index.
// Note: Until February 2013 this block did not have MODE or WHERE inputs.
var list = Blockly.Dart.valueToCode(block, 'LIST',
Blockly.Dart.ORDER_UNARY_POSTFIX) || '[]';
var mode = block.getFieldValue('MODE') || 'GET';
var where = block.getFieldValue('WHERE') || 'FROM_START';
var at = Blockly.Dart.valueToCode(block, 'AT',
Blockly.Dart.ORDER_ADDITIVE) || '1';
var value = Blockly.Dart.valueToCode(block, 'TO',
Blockly.Dart.ORDER_ASSIGNMENT) || 'null';
// Cache non-trivial values to variables to prevent repeated look-ups.
// Closure, which accesses and modifies 'list'.
function cacheList() {
if (list.match(/^\w+$/)) {
return '';
}
var listVar = Blockly.Dart.variableDB_.getDistinctName(
'tmp_list', Blockly.Variables.NAME_TYPE);
var code = 'List ' + listVar + ' = ' + list + ';\n';
list = listVar;
return code;
}
if (where == 'FIRST') {
if (mode == 'SET') {
return list + '[0] = ' + value + ';\n';
} else if (mode == 'INSERT') {
return list + '.insert(0, ' + value + ');\n';
}
} else if (where == 'LAST') {
if (mode == 'SET') {
var code = cacheList();
code += list + '[' + list + '.length - 1] = ' + value + ';\n';
return code;
} else if (mode == 'INSERT') {
return list + '.add(' + value + ');\n';
}
} else if (where == 'FROM_START') {
// Blockly uses one-based indicies.
if (Blockly.isNumber(at)) {
// If the index is a naked number, decrement it right now.
at = parseInt(at, 10) - 1;
} else {
// If the index is dynamic, decrement it in code.
at += ' - 1';
}
if (mode == 'SET') {
return list + '[' + at + '] = ' + value + ';\n';
} else if (mode == 'INSERT') {
return list + '.insert(' + at + ', ' + value + ');\n';
}
} else if (where == 'FROM_END') {
var code = cacheList();
if (mode == 'SET') {
code += list + '[' + list + '.length - ' + at + '] = ' + value + ';\n';
return code;
} else if (mode == 'INSERT') {
code += list + '.insert(' + list + '.length - ' + at + ', ' +
value + ');\n';
return code;
}
} else if (where == 'RANDOM') {
Blockly.Dart.definitions_['import_dart_math'] =
'import \'dart:math\' as Math;';
var code = cacheList();
var xVar = Blockly.Dart.variableDB_.getDistinctName(
'tmp_x', Blockly.Variables.NAME_TYPE);
code += 'int ' + xVar + ' = new Math.Random().nextInt(' + list + '.length);';
if (mode == 'SET') {
code += list + '[' + xVar + '] = ' + value + ';\n';
return code;
} else if (mode == 'INSERT') {
code += list + '.insert(' + xVar + ', ' + value + ');\n';
return code;
}
}
throw 'Unhandled combination (lists_setIndex).';
};
Blockly.Dart['lists_getSublist'] = function(block) {
// Get sublist.
var list = Blockly.Dart.valueToCode(block, 'LIST',
Blockly.Dart.ORDER_UNARY_POSTFIX) || '[]';
var where1 = block.getFieldValue('WHERE1');
var where2 = block.getFieldValue('WHERE2');
var at1 = Blockly.Dart.valueToCode(block, 'AT1',
Blockly.Dart.ORDER_NONE) || '1';
var at2 = Blockly.Dart.valueToCode(block, 'AT2',
Blockly.Dart.ORDER_NONE) || '1';
if ((where1 == 'FIRST' || where1 == 'FROM_START' && Blockly.isNumber(at1)) &&
(where2 == 'LAST' || where2 == 'FROM_START' && Blockly.isNumber(at2))) {
// Simple case that can be done inline.
at1 = where1 == 'FIRST' ? 0 : parseInt(at1, 10) - 1;
if (where2 == 'LAST') {
code = list + '.sublist(' + at1 + ')';
} else {
at2 = parseInt(at2, 10);
code = list + '.sublist(' + at1 + ', ' + at2 + ')';
}
} else {
var functionName = Blockly.Dart.provideFunction_(
'lists_get_sublist',
[ 'List ' + Blockly.Dart.FUNCTION_NAME_PLACEHOLDER_ +
'(list, where1, at1, where2, at2) {',
' int getAt(where, at) {',
' if (where == \'FROM_START\') {',
' at--;',
' } else if (where == \'FROM_END\') {',
' at = list.length - at;',
' } else if (where == \'FIRST\') {',
' at = 0;',
' } else if (where == \'LAST\') {',
' at = list.length - 1;',
' } else {',
' throw \'Unhandled option (lists_getSublist).\';',
' }',
' return at;',
' }',
' at1 = getAt(where1, at1);',
' at2 = getAt(where2, at2) + 1;',
' return list.sublist(at1, at2);',
'}']);
var code = functionName + '(' + list + ', \'' +
where1 + '\', ' + at1 + ', \'' + where2 + '\', ' + at2 + ')';
}
return [code, Blockly.Dart.ORDER_UNARY_POSTFIX];
};