Toylang
My first toy language. Created exclusively for learning purposes.
Example
const toylang = require('@dptole/toylang')
const ast = toylang.syntax.parse(`
user-name = 'dptole'
user-name-length = length(user-name)
if(0 < user-name-length < 10) {
print('valid username length. its length is between 1 and 9')
print(user-name)
} else {
print('invalid username')
}
`)
const result = toylang.interpreter.parse(ast)
// It will output
// "valid username length. its length is between 1 and 9"
// "dptole"Click here to see more.
ABNF-like syntax
chunk = [ exp | decl ] *
exp = [ assign | math_operation | func_call | func_def | primitive | variable ] [ ext_exp ] *
assign = variable "=" exp
variable = [ a-z ] + [ [ "-" ] ? [ _a-z0-9 ] + ] *
math_operation = exp [ math_operator exp ] +
math_operator = [ "-" | "+" | "*" | "/" ]
func_call = variable func_call_args_chunk
func_call_args_chunk = "(" [ func_call_args_list ] ? ")"
func_call_args_list = exp [ "," exp ] *
func_def = "f " variable "(" [ func_def_args_list ] ? ")" "{" func_def_chunk "}"
func_def_args_list = variable [ "," variable ] *
func_def_chunk = chunk func_def_return
func_def_return = "return " exp
primitive = [ number | string | boolean | array | object ]
number = [ "+" | "-" ] ? [ 0-9 ] + [ "." [ 0-9 ] + ] ?
string = [ "'" [ ALPHA ] + "'" ] | [ """ [ ALPHA ] + """ ]
boolean = [ "T" | "F" ]
array = "[" [ exp [ "," exp ] * ] ? "]"
object = "{" [ variable "=" exp [ ";" variable "=" exp ] * ] ? "}"
ext_exp = [ ext_object | ext_array | func_call_args_chunk ]
ext_object = "." exp
ext_array = "[" exp "]"
decl = if
if = "if" if_cond_block if_chunk_block [ else ] ?
if_cond_block = "(" cond ")"
cond = [ log_unary ] ? exp [ log_op exp ] *
log_unary = "not"
log_op = ">" | "<" | "==" | "!=" | ">=" | "<=" | "and" | "xor" | "or"
if_chunk_block = "{" chunk "}"
else = [ else_middle ] * else_end
else_middle = "else" if_cond_block if_chunk_block
else_end = "else" if_chunk_block