An adventure with hand crafted parsing in an attempt to create a tiny, Turing incomplete toy language.
Function definitions and function calls
fun average(a, b) {
return (a + b) / 2
}
average(3.14, 2)and that's it for now!
Open and run the project via gitpod.io:
https://gitpod.io/#https://github.com/maciejsmolinski/toy-lang/blob/main/index.ts
Clone the repository, check out the directory and install dependencies
git clone [email protected]:maciejsmolinski/toy-lang.git
cd toy-lang && npm installRun the code and watch for file changes
npm run watchThe output printed on the screen
[INPUT]
fun average(a, b) {
return (a + b) / 2
}
average(3.14, 2)
[TOKENIZE:OUTPUT]
{ type: 'identifier', value: 'fun' }
{ type: 'identifier', value: 'average' }
{ type: 'leftParen' }
{ type: 'identifier', value: 'a' }
{ type: 'comma' }
{ type: 'identifier', value: 'b' }
{ type: 'rightParen' }
{ type: 'leftBrace' }
{ type: 'return' }
{ type: 'leftParen' }
{ type: 'identifier', value: 'a' }
{ type: 'operator', value: '+' }
{ type: 'identifier', value: 'b' }
{ type: 'rightParen' }
{ type: 'operator', value: '/' }
{ type: 'number', value: 2 }
{ type: 'rightBrace' }
{ type: 'identifier', value: 'average' }
{ type: 'leftParen' }
{ type: 'number', value: 3.14 }
{ type: 'comma' }
{ type: 'number', value: 2 }
{ type: 'rightParen' }
[PARSE:OUTPUT]
{
"type": "Program",
"body": [
{
"type": "FunctionDeclaration",
"name": {
"type": "Identifier",
"name": "average"
},
"params": [
{
"type": "Identifier",
"name": "a"
},
{
"type": "Identifier",
"name": "b"
}
],
"body": {
"type": "BlockStatement",
"body": [
{
"type": "ReturnStatement",
"expr": {
"type": "BinaryExpression",
"left": {
"type": "BinaryExpression",
"left": {
"type": "Identifier",
"name": "a"
},
"operator": "+",
"right": {
"type": "Identifier",
"name": "b"
}
},
"operator": "/",
"right": {
"type": "NumericLiteral",
"value": 2
}
}
}
]
}
},
{
"type": "FunctionCall",
"name": {
"type": "Identifier",
"name": "average"
},
"args": [
{
"type": "NumericLiteral",
"value": 3.14
},
{
"type": "NumericLiteral",
"value": 2
}
]
}
]
}