use nom::character::complete::{multispace0, multispace1};
use nom::{alt, delimited, do_parse, map, named, opt, separated_list0, tag, terminated, tuple};
use crate::ast::{FunctionType, Type};
named!(function_type(&str) -> Type, do_parse!(
tag!("fn")
>> multispace1
>> args: map!(opt!(terminated!(separated_list0!(
tuple!(
multispace0,
tag!(","),
multispace0
),
type_
), multispace1)), |args| args.unwrap_or_default())
>> tag!("->")
>> multispace1
>> ret: type_
>> (Type::Function(FunctionType {
args,
ret: Box::new(ret)
}))
));
named!(pub type_(&str) -> Type, alt!(
tag!("int") => { |_| Type::Int } |
tag!("float") => { |_| Type::Float } |
tag!("bool") => { |_| Type::Bool } |
tag!("cstring") => { |_| Type::CString } |
function_type |
delimited!(
tuple!(tag!("("), multispace0),
type_,
tuple!(tag!(")"), multispace0)
)
));
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn simple_types() {
assert_eq!(test_parse!(type_, "int"), Type::Int);
assert_eq!(test_parse!(type_, "float"), Type::Float);
assert_eq!(test_parse!(type_, "bool"), Type::Bool);
assert_eq!(test_parse!(type_, "cstring"), Type::CString);
}
#[test]
fn no_arg_fn_type() {
assert_eq!(
test_parse!(type_, "fn -> int"),
Type::Function(FunctionType {
args: vec![],
ret: Box::new(Type::Int)
})
);
}
#[test]
fn fn_type_with_args() {
assert_eq!(
test_parse!(type_, "fn int, bool -> int"),
Type::Function(FunctionType {
args: vec![Type::Int, Type::Bool],
ret: Box::new(Type::Int)
})
);
}
#[test]
fn fn_taking_fn() {
assert_eq!(
test_parse!(type_, "fn fn int, bool -> bool, float -> float"),
Type::Function(FunctionType {
args: vec![
Type::Function(FunctionType {
args: vec![Type::Int, Type::Bool],
ret: Box::new(Type::Bool)
}),
Type::Float
],
ret: Box::new(Type::Float)
})
)
}
#[test]
fn parenthesized() {
assert_eq!(
test_parse!(type_, "fn (fn int, bool -> bool), float -> float"),
Type::Function(FunctionType {
args: vec![
Type::Function(FunctionType {
args: vec![Type::Int, Type::Bool],
ret: Box::new(Type::Bool)
}),
Type::Float
],
ret: Box::new(Type::Float)
})
)
}
}