schala/src/rukka_lang/mod.rs

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use itertools::Itertools;
use schala_lib::{ProgrammingLanguageInterface, EvalOptions, ReplOutput};
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use std::iter::Peekable;
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use std::vec::IntoIter;
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use std::str::Chars;
pub struct Rukka { }
impl Rukka {
pub fn new() -> Rukka { Rukka { } }
}
impl ProgrammingLanguageInterface for Rukka {
fn get_language_name(&self) -> String {
"Rukka".to_string()
}
fn get_source_file_suffix(&self) -> String {
format!("rukka")
}
fn evaluate_in_repl(&mut self, input: &str, _eval_options: &EvalOptions) -> ReplOutput {
let mut output = ReplOutput::default();
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let sexps = match read(input) {
Err(err) => {
output.add_output(format!("Error: {}", err));
return output;
},
Ok(sexps) => sexps
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};
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let mut text = String::new();
for (i, sexp) in sexps.into_iter().enumerate() {
match eval(sexp) {
Ok(result) => text.push_str(&format!("{}: {}", i, result)),
Err(err) => text.push_str(&format!("{} Error: {}", i, err)),
}
}
output.add_output(text);
output
}
}
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fn eval(ast: Sexp) -> Result<String, String> {
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Ok(format!("{:?}", ast))
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}
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fn read(input: &str) -> Result<Vec<Sexp>, String> {
let mut chars: Peekable<Chars> = input.chars().peekable();
let mut tokens = tokenize(&mut chars).into_iter().peekable();
let mut sexps = Vec::new();
loop {
sexps.push(parse(&mut tokens)?);
if let None = tokens.peek() {
break;
}
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}
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Ok(sexps)
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}
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#[derive(Debug)]
enum Token {
LParen,
RParen,
Symbol(String)
}
fn tokenize(input: &mut Peekable<Chars>) -> Vec<Token> {
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use self::Token::*;
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let mut tokens = Vec::new();
loop {
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match input.next() {
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None => break,
Some('(') => tokens.push(LParen),
Some(')') => tokens.push(RParen),
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Some(c) if c.is_whitespace() => continue,
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Some(c) => {
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let mut sym = String::new();
sym.push(c);
loop {
match input.peek().map(|x| *x) {
Some('(') | Some(')') | None => break,
Some(c) if c.is_whitespace() => break,
Some(c) => {
sym.push(c);
input.next();
}
}
}
tokens.push(Symbol(sym));
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}
}
}
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tokens
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}
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fn parse(tokens: &mut Peekable<IntoIter<Token>>) -> Result<Sexp, String> {
use self::Token::*;
match tokens.next() {
Some(Symbol(s)) => Ok(Sexp::Atom(AtomT::Symbol(s))),
Some(LParen) => parse_sexp(tokens),
Some(RParen) => Err(format!("Unexpected ')'")),
None => Err(format!("Unexpected end of input")),
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}
}
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fn parse_sexp(tokens: &mut Peekable<IntoIter<Token>>) -> Result<Sexp, String> {
use self::Token::*;
let mut vec = Vec::new();
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loop {
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match tokens.peek() {
None => return Err(format!("Unexpected end of input")),
Some(&RParen) => { tokens.next(); break},
_ => vec.push(parse(tokens)?),
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}
}
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Ok(Sexp::List(vec))
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}
#[derive(Debug)]
enum Sexp {
Atom(AtomT),
List(Vec<Sexp>),
}
#[derive(Debug)]
enum AtomT {
Symbol(String),
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//Number(u64),
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}
#[derive(Debug)]
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struct PointerList<'a> {
next: Option<&'a PointerList<'a>>,
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data: usize
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}
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