1 files changed, 152 insertions, 0 deletions
diff --git a/users/aspen/achilles/src/parser/type_.rs b/users/aspen/achilles/src/parser/type_.rs
new file mode 100644
index 0000000000..b80f0e0860
--- /dev/null
+++ b/users/aspen/achilles/src/parser/type_.rs
@@ -0,0 +1,152 @@
+use nom::character::complete::{multispace0, multispace1};
+use nom::{alt, delimited, do_parse, map, named, opt, separated_list0, tag, terminated, tuple};
+
+use super::ident;
+use super::util::comma;
+use crate::ast::{FunctionType, Type};
+
+named!(pub function_type(&str) -> FunctionType, do_parse!(
+    tag!("fn")
+        >> multispace1
+        >> args: map!(opt!(terminated!(separated_list0!(
+            comma,
+            type_
+        ), multispace1)), |args| args.unwrap_or_default())
+        >> tag!("->")
+        >> multispace1
+        >> ret: type_
+        >> (FunctionType {
+            args,
+            ret: Box::new(ret)
+        })
+));
+
+named!(tuple_type(&str) -> Type, do_parse!(
+    tag!("(")
+        >> multispace0
+        >> fst: type_
+        >> comma
+        >> rest: separated_list0!(
+            comma,
+            type_
+        )
+        >> multispace0
+        >> tag!(")")
+        >> ({
+            let mut members = Vec::with_capacity(rest.len() + 1);
+            members.push(fst);
+            members.append(&mut rest.clone());
+            Type::Tuple(members)
+        })
+));
+
+named!(pub type_(&str) -> Type, alt!(
+    tag!("int") => { |_| Type::Int } |
+    tag!("float") => { |_| Type::Float } |
+    tag!("bool") => { |_| Type::Bool } |
+    tag!("cstring") => { |_| Type::CString } |
+    tag!("()") => { |_| Type::Unit } |
+    tuple_type |
+    function_type => { |ft| Type::Function(ft) }|
+    ident => { |id| Type::Var(id) } |
+    delimited!(
+        tuple!(tag!("("), multispace0),
+        type_,
+        tuple!(tag!(")"), multispace0)
+    )
+));
+
+#[cfg(test)]
+mod tests {
+    use std::convert::TryFrom;
+
+    use super::*;
+    use crate::ast::Ident;
+
+    #[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);
+        assert_eq!(test_parse!(type_, "()"), Type::Unit);
+    }
+
+    #[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)
+            })
+        )
+    }
+
+    #[test]
+    fn tuple() {
+        assert_eq!(
+            test_parse!(type_, "(int, int)"),
+            Type::Tuple(vec![Type::Int, Type::Int])
+        )
+    }
+
+    #[test]
+    fn type_vars() {
+        assert_eq!(
+            test_parse!(type_, "fn x, y -> x"),
+            Type::Function(FunctionType {
+                args: vec![
+                    Type::Var(Ident::try_from("x").unwrap()),
+                    Type::Var(Ident::try_from("y").unwrap()),
+                ],
+                ret: Box::new(Type::Var(Ident::try_from("x").unwrap())),
+            })
+        )
+    }
+}