just a small toy language
let inc = 1
let ret = 0
while true {
if inc > 100 {
break
}
ret = ret + inc
inc = inc + 1
}
print(ret) #print 5050
let i = 1
let end = 100
let total = 0
func add() {
if i <= end {
total = total + i
i = i+1
add()
}
}
add()
print(total) #print 5050
func create() {
let i = 0
func inc() {
i = i + 1
print(i)
}
return inc
}
let add = create()
add() #print 1
add() #print 2
add() #print 3
print(factorial(5)) #print 120
func factorial(n) {
if n <= 1 {
return 1
}
return factorial(n - 1) * n
}
$ npm install yulang
'use strict';
var YuLang = require('./lib/yulang');
var Parser = YuLang.Parser;
var Interpreter = YuLang.Interpreter;
let test = `
func create() {
let i = 0
func inc() {
i = i + 1
print(i)
}
return inc
}
let add = create()
add() #print 1
add() #print 2
add() #print 3
func factorial(n) {
if n <= 1 {
return 1
}
return factorial(n - 1) * n
}
print(factorial(5)) #print 120
`;
var ast = Parser.parse(test);
console.log('AST:')
console.log(JSON.stringify(ast, null, 4));
try {
var it = new Interpreter(ast);
it.execute();
}catch(e) {
console.log(e.stack);
}AST:
{
"type": "Program",
"body": [
{
"type": "FunctionDeclarationStatement",
"id": {
"type": "Identifier",
"name": "create"
},
"params": null,
"body": {
"type": "BlockStatement",
"body": [
{
"type": "VariableDeclarator",
"id": {
"type": "Identifier",
"name": "i"
},
"init": {
"type": "Literal",
"value": 0,
"raw": "0"
}
},
{
"type": "FunctionDeclarationStatement",
"id": {
"type": "Identifier",
"name": "inc"
},
"params": null,
"body": {
"type": "BlockStatement",
"body": [
{
"type": "ExpressionStatement",
"expression": {
"type": "AssignmentExpression",
"operator": "=",
"left": {
"type": "Identifier",
"name": "i"
},
"right": {
"type": "BinaryExpression",
"operator": "+",
"left": {
"type": "Identifier",
"name": "i"
},
"right": {
"type": "Literal",
"value": 1,
"raw": "1"
}
}
}
},
{
"type": "ExpressionStatement",
"expression": {
"type": "CallExpression",
"callee": {
"type": "Identifier",
"name": "print"
},
"arguments": [
{
"type": "Identifier",
"name": "i"
}
]
}
}
]
}
},
{
"type": "ReturnStatement",
"argument": {
"type": "Identifier",
"name": "inc"
}
}
]
}
},
{
"type": "VariableDeclarator",
"id": {
"type": "Identifier",
"name": "add"
},
"init": {
"type": "CallExpression",
"callee": {
"type": "Identifier",
"name": "create"
},
"arguments": null
}
},
{
"type": "ExpressionStatement",
"expression": {
"type": "CallExpression",
"callee": {
"type": "Identifier",
"name": "add"
},
"arguments": null
}
},
{
"type": "ExpressionStatement",
"expression": {
"type": "CallExpression",
"callee": {
"type": "Identifier",
"name": "add"
},
"arguments": null
}
},
{
"type": "ExpressionStatement",
"expression": {
"type": "CallExpression",
"callee": {
"type": "Identifier",
"name": "add"
},
"arguments": null
}
},
{
"type": "FunctionDeclarationStatement",
"id": {
"type": "Identifier",
"name": "factorial"
},
"params": [
{
"type": "Identifier",
"name": "n"
}
],
"body": {
"type": "BlockStatement",
"body": [
{
"type": "IFStatement",
"test": {
"type": "BinaryExpression",
"operator": "<=",
"left": {
"type": "Identifier",
"name": "n"
},
"right": {
"type": "Literal",
"value": 1,
"raw": "1"
}
},
"consequent": {
"type": "BlockStatement",
"body": [
{
"type": "ReturnStatement",
"argument": {
"type": "Literal",
"value": 1,
"raw": "1"
}
}
]
}
},
{
"type": "ReturnStatement",
"argument": {
"type": "BinaryExpression",
"operator": "*",
"left": {
"type": "CallExpression",
"callee": {
"type": "Identifier",
"name": "factorial"
},
"arguments": [
{
"type": "BinaryExpression",
"operator": "-",
"left": {
"type": "Identifier",
"name": "n"
},
"right": {
"type": "Literal",
"value": 1,
"raw": "1"
}
}
]
},
"right": {
"type": "Identifier",
"name": "n"
}
}
}
]
}
},
{
"type": "ExpressionStatement",
"expression": {
"type": "CallExpression",
"callee": {
"type": "Identifier",
"name": "print"
},
"arguments": [
{
"type": "CallExpression",
"callee": {
"type": "Identifier",
"name": "factorial"
},
"arguments": [
{
"type": "Literal",
"value": 5,
"raw": "5"
}
]
}
]
}
}
]
}
Result is:
1
2
3
120