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scratch-blocks/generators/javascript/math.js
ellen.spertus 08f4022b38 Automatic commit Sat Jan 11 03:00:02 PST 2014
2014-01-11 03:00:02 -08:00

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JavaScript
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/**
* Visual Blocks Language
*
* Copyright 2012 Google Inc.
* http://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 JavaScript for math blocks.
* @author q.neutron@gmail.com (Quynh Neutron)
*/
'use strict';
goog.provide('Blockly.JavaScript.math');
goog.require('Blockly.JavaScript');
Blockly.JavaScript['math_number'] = function(block) {
// Numeric value.
var code = parseFloat(block.getFieldValue('NUM'));
return [code, Blockly.JavaScript.ORDER_ATOMIC];
};
Blockly.JavaScript['math_arithmetic'] = function(block) {
// Basic arithmetic operators, and power.
var OPERATORS = {
ADD: [' + ', Blockly.JavaScript.ORDER_ADDITION],
MINUS: [' - ', Blockly.JavaScript.ORDER_SUBTRACTION],
MULTIPLY: [' * ', Blockly.JavaScript.ORDER_MULTIPLICATION],
DIVIDE: [' / ', Blockly.JavaScript.ORDER_DIVISION],
POWER: [null, Blockly.JavaScript.ORDER_COMMA] // Handle power separately.
};
var tuple = OPERATORS[block.getFieldValue('OP')];
var operator = tuple[0];
var order = tuple[1];
var argument0 = Blockly.JavaScript.valueToCode(block, 'A', order) || '0';
var argument1 = Blockly.JavaScript.valueToCode(block, 'B', order) || '0';
var code;
// Power in JavaScript requires a special case since it has no operator.
if (!operator) {
code = 'Math.pow(' + argument0 + ', ' + argument1 + ')';
return [code, Blockly.JavaScript.ORDER_FUNCTION_CALL];
}
code = argument0 + operator + argument1;
return [code, order];
};
Blockly.JavaScript['math_single'] = function(block) {
// Math operators with single operand.
var operator = block.getFieldValue('OP');
var code;
var arg;
if (operator == 'NEG') {
// Negation is a special case given its different operator precedence.
arg = Blockly.JavaScript.valueToCode(block, 'NUM',
Blockly.JavaScript.ORDER_UNARY_NEGATION) || '0';
if (arg[0] == '-') {
// --3 is not legal in JS.
arg = ' ' + arg;
}
code = '-' + arg;
return [code, Blockly.JavaScript.ORDER_UNARY_NEGATION];
}
if (operator == 'SIN' || operator == 'COS' || operator == 'TAN') {
arg = Blockly.JavaScript.valueToCode(block, 'NUM',
Blockly.JavaScript.ORDER_DIVISION) || '0';
} else {
arg = Blockly.JavaScript.valueToCode(block, 'NUM',
Blockly.JavaScript.ORDER_NONE) || '0';
}
// First, handle cases which generate values that don't need parentheses
// wrapping the code.
switch (operator) {
case 'ABS':
code = 'Math.abs(' + arg + ')';
break;
case 'ROOT':
code = 'Math.sqrt(' + arg + ')';
break;
case 'LN':
code = 'Math.log(' + arg + ')';
break;
case 'EXP':
code = 'Math.exp(' + arg + ')';
break;
case 'POW10':
code = 'Math.pow(10,' + arg + ')';
break;
case 'ROUND':
code = 'Math.round(' + arg + ')';
break;
case 'ROUNDUP':
code = 'Math.ceil(' + arg + ')';
break;
case 'ROUNDDOWN':
code = 'Math.floor(' + arg + ')';
break;
case 'SIN':
code = 'Math.sin(' + arg + ' / 180 * Math.PI)';
break;
case 'COS':
code = 'Math.cos(' + arg + ' / 180 * Math.PI)';
break;
case 'TAN':
code = 'Math.tan(' + arg + ' / 180 * Math.PI)';
break;
}
if (code) {
return [code, Blockly.JavaScript.ORDER_FUNCTION_CALL];
}
// Second, handle cases which generate values that may need parentheses
// wrapping the code.
switch (operator) {
case 'LOG10':
code = 'Math.log(' + arg + ') / Math.log(10)';
break;
case 'ASIN':
code = 'Math.asin(' + arg + ') / Math.PI * 180';
break;
case 'ACOS':
code = 'Math.acos(' + arg + ') / Math.PI * 180';
break;
case 'ATAN':
code = 'Math.atan(' + arg + ') / Math.PI * 180';
break;
default:
throw 'Unknown math operator: ' + operator;
}
return [code, Blockly.JavaScript.ORDER_DIVISION];
};
Blockly.JavaScript['math_constant'] = function(block) {
// Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
var CONSTANTS = {
PI: ['Math.PI', Blockly.JavaScript.ORDER_MEMBER],
E: ['Math.E', Blockly.JavaScript.ORDER_MEMBER],
GOLDEN_RATIO: ['(1 + Math.sqrt(5)) / 2', Blockly.JavaScript.ORDER_DIVISION],
SQRT2: ['Math.SQRT2', Blockly.JavaScript.ORDER_MEMBER],
SQRT1_2: ['Math.SQRT1_2', Blockly.JavaScript.ORDER_MEMBER],
INFINITY: ['Infinity', Blockly.JavaScript.ORDER_ATOMIC]
};
return CONSTANTS[block.getFieldValue('CONSTANT')];
};
Blockly.JavaScript['math_number_property'] = function(block) {
// Check if a number is even, odd, prime, whole, positive, or negative
// or if it is divisible by certain number. Returns true or false.
var number_to_check = Blockly.JavaScript.valueToCode(block, 'NUMBER_TO_CHECK',
Blockly.JavaScript.ORDER_MODULUS) || '0';
var dropdown_property = block.getFieldValue('PROPERTY');
var code;
if (dropdown_property == 'PRIME') {
// Prime is a special case as it is not a one-liner test.
var functionName = Blockly.JavaScript.provideFunction_(
'math_isPrime',
[ 'function ' + Blockly.JavaScript.FUNCTION_NAME_PLACEHOLDER_ + '(n) {',
' // https://en.wikipedia.org/wiki/Primality_test#Naive_methods',
' if (n == 2 || n == 3) {',
' return true;',
' }',
' // False if n is NaN, negative, is 1, or not whole.',
' // And false if n is divisible by 2 or 3.',
' if (isNaN(n) || n <= 1 || n % 1 != 0 || n % 2 == 0 ||' +
' n % 3 == 0) {',
' return false;',
' }',
' // Check all the numbers of form 6k +/- 1, up to sqrt(n).',
' for (var x = 6; x <= Math.sqrt(n) + 1; x += 6) {',
' if (n % (x - 1) == 0 || n % (x + 1) == 0) {',
' return false;',
' }',
' }',
' return true;',
'}']);
code = functionName + '(' + number_to_check + ')';
return [code, Blockly.JavaScript.ORDER_FUNCTION_CALL];
}
switch (dropdown_property) {
case 'EVEN':
code = number_to_check + ' % 2 == 0';
break;
case 'ODD':
code = number_to_check + ' % 2 == 1';
break;
case 'WHOLE':
code = number_to_check + ' % 1 == 0';
break;
case 'POSITIVE':
code = number_to_check + ' > 0';
break;
case 'NEGATIVE':
code = number_to_check + ' < 0';
break;
case 'DIVISIBLE_BY':
var divisor = Blockly.JavaScript.valueToCode(block, 'DIVISOR',
Blockly.JavaScript.ORDER_MODULUS) || '0';
code = number_to_check + ' % ' + divisor + ' == 0';
break;
}
return [code, Blockly.JavaScript.ORDER_EQUALITY];
};
Blockly.JavaScript['math_change'] = function(block) {
// Add to a variable in place.
var argument0 = Blockly.JavaScript.valueToCode(block, 'DELTA',
Blockly.JavaScript.ORDER_ADDITION) || '0';
var varName = Blockly.JavaScript.variableDB_.getName(
block.getFieldValue('VAR'), Blockly.Variables.NAME_TYPE);
return varName + ' = (typeof ' + varName + ' == \'number\' ? ' + varName +
' : 0) + ' + argument0 + ';\n';
};
// Rounding functions have a single operand.
Blockly.JavaScript['math_round'] = Blockly.JavaScript['math_single'];
// Trigonometry functions have a single operand.
Blockly.JavaScript['math_trig'] = Blockly.JavaScript['math_single'];
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_COMMA) || '[]';
code = 'Math.min.apply(null, ' + list + ')';
break;
case 'MAX':
list = Blockly.JavaScript.valueToCode(block, 'LIST',
Blockly.JavaScript.ORDER_COMMA) || '[]';
code = 'Math.max.apply(null, ' + list + ')';
break;
case 'AVERAGE':
// math_median([null,null,1,3]) == 2.0.
var functionName = Blockly.JavaScript.provideFunction_(
'math_mean',
[ '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':
// math_median([null,null,1,3]) == 2.0.
var functionName = Blockly.JavaScript.provideFunction_(
'math_median',
[ '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_(
'math_modes',
[ '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_(
'math_standard_deviation',
[ '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_(
'math_random_list',
[ '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 'Unknown operator: ' + func;
}
return [code, Blockly.JavaScript.ORDER_FUNCTION_CALL];
};
Blockly.JavaScript['math_modulo'] = function(block) {
// Remainder computation.
var argument0 = Blockly.JavaScript.valueToCode(block, 'DIVIDEND',
Blockly.JavaScript.ORDER_MODULUS) || '0';
var argument1 = Blockly.JavaScript.valueToCode(block, 'DIVISOR',
Blockly.JavaScript.ORDER_MODULUS) || '0';
var code = argument0 + ' % ' + argument1;
return [code, Blockly.JavaScript.ORDER_MODULUS];
};
Blockly.JavaScript['math_constrain'] = function(block) {
// Constrain a number between two limits.
var argument0 = Blockly.JavaScript.valueToCode(block, 'VALUE',
Blockly.JavaScript.ORDER_COMMA) || '0';
var argument1 = Blockly.JavaScript.valueToCode(block, 'LOW',
Blockly.JavaScript.ORDER_COMMA) || '0';
var argument2 = Blockly.JavaScript.valueToCode(block, 'HIGH',
Blockly.JavaScript.ORDER_COMMA) || 'Infinity';
var code = 'Math.min(Math.max(' + argument0 + ', ' + argument1 + '), ' +
argument2 + ')';
return [code, Blockly.JavaScript.ORDER_FUNCTION_CALL];
};
Blockly.JavaScript['math_random_int'] = function(block) {
// Random integer between [X] and [Y].
var argument0 = Blockly.JavaScript.valueToCode(block, 'FROM',
Blockly.JavaScript.ORDER_COMMA) || '0';
var argument1 = Blockly.JavaScript.valueToCode(block, 'TO',
Blockly.JavaScript.ORDER_COMMA) || '0';
var functionName = Blockly.JavaScript.provideFunction_(
'math_random_int',
[ 'function ' + Blockly.JavaScript.FUNCTION_NAME_PLACEHOLDER_ +
'(a, b) {',
' if (a > b) {',
' // Swap a and b to ensure a is smaller.',
' var c = a;',
' a = b;',
' b = c;',
' }',
' return Math.floor(Math.random() * (b - a + 1) + a);',
'}']);
var code = functionName + '(' + argument0 + ', ' + argument1 + ')';
return [code, Blockly.JavaScript.ORDER_FUNCTION_CALL];
};
Blockly.JavaScript['math_random_float'] = function(block) {
// Random fraction between 0 and 1.
return ['Math.random()', Blockly.JavaScript.ORDER_FUNCTION_CALL];
};
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