diff options
Diffstat (limited to 'src/parser/mod.rs')
| -rw-r--r-- | src/parser/mod.rs | 167 |
1 files changed, 154 insertions, 13 deletions
diff --git a/src/parser/mod.rs b/src/parser/mod.rs index 811450da0d61..be432b8adf56 100644 --- a/src/parser/mod.rs +++ b/src/parser/mod.rs @@ -156,6 +156,10 @@ where } } +fn is_reserved(s: &str) -> bool { + matches!(s, "if" | "then" | "else" | "let" | "in" | "fn") +} + fn ident<'a, E>(i: &'a str) -> nom::IResult<&'a str, Ident, E> where E: ParseError<&'a str>, @@ -170,7 +174,12 @@ where } idx += 1; } - Ok((&i[idx..], Ident::from_str_unchecked(&i[..idx]))) + let id = &i[..idx]; + if is_reserved(id) { + Err(nom::Err::Error(E::from_error_kind(i, ErrorKind::Satisfy))) + } else { + Ok((&i[idx..], Ident::from_str_unchecked(id))) + } } else { Err(nom::Err::Error(E::from_error_kind(i, ErrorKind::Satisfy))) } @@ -228,14 +237,65 @@ named!(if_(&str) -> Expr, do_parse! ( named!(ident_expr(&str) -> Expr, map!(ident, Expr::Ident)); +named!(paren_expr(&str) -> Expr, + delimited!(complete!(tag!("(")), expr, complete!(tag!(")")))); + +named!(funcref(&str) -> Expr, alt!( + ident_expr | + paren_expr +)); + +named!(no_arg_call(&str) -> Expr, do_parse!( + fun: funcref + >> multispace0 + >> complete!(tag!("()")) + >> (Expr::Call { + fun: Box::new(fun), + args: vec![], + }) +)); + +named!(fun_expr(&str) -> Expr, do_parse!( + tag!("fn") + >> multispace1 + >> args: separated_list0!(multispace1, ident) + >> multispace0 + >> char!('=') + >> multispace0 + >> body: expr + >> (Expr::Fun(Box::new(Fun { + args, + body + }))) +)); + +named!(arg(&str) -> Expr, alt!( + ident_expr | + literal | + paren_expr +)); + +named!(call_with_args(&str) -> Expr, do_parse!( + fun: funcref + >> multispace1 + >> args: separated_list1!(multispace1, arg) + >> (Expr::Call { + fun: Box::new(fun), + args + }) +)); + named!(simple_expr(&str) -> Expr, alt!( let_ | if_ | + fun_expr | literal | ident_expr )); named!(pub expr(&str) -> Expr, alt!( + no_arg_call | + call_with_args | map!(token_tree, |tt| { ExprParser.parse(&mut tt.into_iter()).unwrap() }) | @@ -243,8 +303,8 @@ named!(pub expr(&str) -> Expr, alt!( ////// -named!(fun(&str) -> Fun, do_parse!( - tag!("fn") +named!(fun_decl(&str) -> Decl, do_parse!( + complete!(tag!("fn")) >> multispace0 >> name: ident >> multispace1 @@ -253,21 +313,24 @@ named!(fun(&str) -> Fun, do_parse!( >> char!('=') >> multispace0 >> body: expr - >> (Fun { + >> (Decl::Fun { name, - args, - body + body: Fun { + args, + body + } }) )); named!(pub decl(&str) -> Decl, alt!( - fun => { |f| Decl::Fun(f) } + fun_decl )); -named!(pub toplevel(&str) -> Vec<Decl>, separated_list0!(multispace1, decl)); +named!(pub toplevel(&str) -> Vec<Decl>, many0!(decl)); #[cfg(test)] mod tests { + use nom_trace::print_trace; use std::convert::{TryFrom, TryInto}; use super::*; @@ -281,7 +344,9 @@ mod tests { macro_rules! test_parse { ($parser: ident, $src: expr) => {{ - let (rem, res) = $parser($src).unwrap(); + let res = $parser($src); + print_trace!(); + let (rem, res) = res.unwrap(); assert!( rem.is_empty(), "non-empty remainder: \"{}\", parsed: {:?}", @@ -435,11 +500,87 @@ mod tests { let res = test_parse!(decl, "fn id x = x"); assert_eq!( res, - Decl::Fun(Fun { + Decl::Fun { name: "id".try_into().unwrap(), - args: vec!["x".try_into().unwrap()], - body: *ident_expr("x"), - }) + body: Fun { + args: vec!["x".try_into().unwrap()], + body: *ident_expr("x"), + } + } ) } + + #[test] + fn no_arg_call() { + let res = test_parse!(expr, "f()"); + assert_eq!( + res, + Expr::Call { + fun: ident_expr("f"), + args: vec![] + } + ); + } + + #[test] + fn call_with_args() { + let res = test_parse!(expr, "f x 1"); + assert_eq!( + res, + Expr::Call { + fun: ident_expr("f"), + args: vec![*ident_expr("x"), Expr::Literal(Literal::Int(1))] + } + ) + } + + #[test] + fn call_funcref() { + let res = test_parse!(expr, "(let x = 1 in x) 2"); + assert_eq!( + res, + Expr::Call { + fun: Box::new(Expr::Let { + bindings: vec![( + Ident::try_from("x").unwrap(), + Expr::Literal(Literal::Int(1)) + )], + body: ident_expr("x") + }), + args: vec![Expr::Literal(Literal::Int(2))] + } + ) + } + + #[test] + fn anon_function() { + let res = test_parse!(expr, "let id = fn x = x in id 1"); + assert_eq!( + res, + Expr::Let { + bindings: vec![( + Ident::try_from("id").unwrap(), + Expr::Fun(Box::new(Fun { + args: vec![Ident::try_from("x").unwrap()], + body: *ident_expr("x") + })) + )], + body: Box::new(Expr::Call { + fun: ident_expr("id"), + args: vec![Expr::Literal(Literal::Int(1))], + }) + } + ); + } + + #[test] + fn multiple_decls() { + let res = test_parse!( + toplevel, + "fn id x = x + fn plus x y = x + y + fn main = plus (id 2) 7" + ); + assert_eq!(res.len(), 3); + } } |