81 lines
2.9 KiB
Rust
81 lines
2.9 KiB
Rust
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#[macro_use] extern crate lalrpop_util;
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lalrpop_mod!(pub grammar);
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use std::rc::Rc;
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mod ast;
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use crate::ast::Form;
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#[test]
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fn parse_test() {
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assert!(grammar::TermParser::new().parse("22").is_ok());
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assert!(grammar::TermParser::new().parse("(22)").is_ok());
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assert!(grammar::TermParser::new().parse("(((22)))").is_ok());
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assert!(grammar::TermParser::new().parse("((22)").is_err());
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assert!(grammar::TermParser::new().parse("22").is_ok());
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assert!(grammar::TermParser::new().parse("(22)").is_ok());
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assert!(grammar::TermParser::new().parse("(22 )").is_ok());
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assert!(grammar::TermParser::new().parse("()").is_ok());
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assert!(grammar::TermParser::new().parse("( )").is_ok());
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assert!(grammar::TermParser::new().parse("( 44)").is_ok());
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assert!(grammar::TermParser::new().parse("(44 )").is_ok());
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assert!(grammar::TermParser::new().parse("(22 44 (1) 33 (4 5 (6) 6))").is_ok());
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assert!(grammar::TermParser::new().parse("hello").is_ok());
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assert!(grammar::TermParser::new().parse("-").is_ok());
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assert!(grammar::TermParser::new().parse("+").is_ok());
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assert!(grammar::TermParser::new().parse("(+ 1 ;hi
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3)").is_ok());
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assert!(grammar::TermParser::new().parse("'13").is_ok());
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assert!(grammar::TermParser::new().parse("hello-world").is_ok());
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assert!(grammar::TermParser::new().parse("_").is_ok());
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}
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fn eval(e: Rc<Form>, f: Rc<Form>) -> Rc<Form> {
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let mut e = e;
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let mut x = Option::Some(f);
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loop {
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let cur = x.take().unwrap();
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match *cur {
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Form::Symbol(ref s) => {
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let mut t = e;
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while s != t.car().unwrap().car().unwrap().sym().unwrap() {
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t = t.cdr().unwrap();
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}
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return t.car().unwrap().cdr().unwrap();
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},
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Form::Pair(ref c, ref p) => {
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let comb = eval(Rc::clone(&e), Rc::clone(c));
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match *comb {
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Form::PrimComb(ref n, ref f) => return f(e, Rc::clone(p)),
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_ => panic!("Tried to call not a PrimComb {:?}", comb),
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}
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},
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_ => return cur,
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}
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}
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}
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fn main() {
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fn assoc(kvs: Vec<(&str, Rc<Form>)>) -> Rc<Form> {
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let mut to_ret = Rc::new(Form::Nil);
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for (k, v) in kvs {
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to_ret = Rc::new(Form::Pair(
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Rc::new(Form::Pair(
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Rc::new(Form::Symbol(k.to_owned())),
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v)),
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to_ret));
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}
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to_ret
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}
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let env = assoc(vec![
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("+", Rc::new(Form::PrimComb("+".to_owned(), |e, p| {
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Rc::new(Form::Int(p.car().unwrap().int().unwrap() + p.cdr().unwrap().car().unwrap().int().unwrap()))
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})))
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]);
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let input = "(+ 2 2)";
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let result = eval(env, Rc::new(grammar::TermParser::new().parse(input).unwrap()));
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println!("Result is {:?}", result);
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}
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