Added term level type literals (for function type signatures)

1 files changed, 18 insertions, 1 deletions

diff --git a/src/sexp/mod.rs b/src/sexp/mod.rs
index 296553f..11c185f 100644
--- a/src/sexp/mod.rs
+++ b/src/sexp/mod.rs
@@ -4,6 +4,8 @@ pub mod util;
 pub mod subst;
 pub mod display;
 
+use crate::r#type::Type;
+
 /// A leaf node for S-Expressions.
 ///
 /// May represent built-in operators,
@@ -33,6 +35,9 @@ pub enum SLeaf {
 
     Let,
 
+    Ty(Type),
+    Arr,
+
     Print,
 
     Int(i32),
@@ -58,6 +63,7 @@ pub enum SExp {
 
 use SExp::*;
 use SLeaf::*;
+use crate::sexp::util::*;
 
 
 impl SExp {
@@ -71,7 +77,7 @@ impl SExp {
             SCons(a, b) =>
                 SCons(a.clone(), b.clone()).check_let().is_some() ||
                 (
-                    (**a == Atom(Quote) || **a == Atom(Vector))
+                    (**a == Atom(Quote) || **a == Atom(Vector) || (**a).is_type_lit())
                     && b.consists_of_values()
                 ),
             Atom(Var(_)) => false,
@@ -85,4 +91,15 @@ impl SExp {
             _ => false
         }
     }
+
+    pub fn is_type_lit(&self) -> bool {
+	match self {
+	    Atom(Ty(_)) => true,
+	    SCons(a, b) => scons(a.clone(), b.clone())
+		.parts()
+		.into_iter()
+		.all(|x| x.is_type_lit()),
+	    _ => false
+	}
+    }
 }