Added tests for functions

3 files changed, 27 insertions, 0 deletions

diff --git a/src/sexp/display.rs b/src/sexp/display.rs
index 5d78e93..eff3904 100644
--- a/src/sexp/display.rs
+++ b/src/sexp/display.rs
@@ -29,6 +29,7 @@ impl fmt::Display for SLeaf {
             Vector => "vector".to_string(),
 	    Print  => "print".to_string(),
             Let    => "let".to_string(),
+	    Fun    => "fn".to_string(),
 	    Ty(t)  => t.to_string(),
 	    Arr    => "->".to_string(),
             Nil    => "()".to_string(),
diff --git a/src/sexp/mod.rs b/src/sexp/mod.rs
index 11c185f..4bb4fa2 100644
--- a/src/sexp/mod.rs
+++ b/src/sexp/mod.rs
@@ -35,6 +35,8 @@ pub enum SLeaf {
 
     Let,
 
+    Fun,
+
     Ty(Type),
     Arr,
 
@@ -75,6 +77,7 @@ impl SExp {
     pub fn is_value(&self) -> bool {
         match self {
             SCons(a, b) =>
+		scons(a.clone(), b.clone()).is_fun() ||
                 SCons(a.clone(), b.clone()).check_let().is_some() ||
                 (
                     (**a == Atom(Quote) || **a == Atom(Vector) || (**a).is_type_lit())
@@ -102,4 +105,11 @@ impl SExp {
 	    _ => false
 	}
     }
+
+    pub fn is_fun(&self) -> bool {
+	match self {
+	    SCons(a, _) if **a == Atom(Fun) => true,
+	    _ => false
+	}
+    }
 }
diff --git a/src/sexp/step.rs b/src/sexp/step.rs
index c26dce9..8cc1e64 100644
--- a/src/sexp/step.rs
+++ b/src/sexp/step.rs
@@ -270,6 +270,22 @@ impl SExp {
     /// );
     /// ```
     ///
+    /// **Functions**
+    /// ```rust
+    /// use myslip::{sexp::{SExp::*, SLeaf::*, util::*}, r#type::{Type::*, util::*}};
+    ///
+    /// let varlist = scons(var("a"), scons(var("b"), Nil));
+    /// let typelist = scons(Ty(List(vec![Integer])), Nil);
+    /// let ret = Atom(Ty(Boolean));
+    /// let body = scons(Gt, varlist.clone());
+    /// let fun = scons(Fun, scons(varlist, scons(typelist, scons(ret, scons(body, Nil)))));
+    /// let args = scons(2, scons(1, Nil));
+    /// assert_eq!(
+    ///     scons(fun, scons(args, Nil)).multistep(),
+    ///     Ok(Atom(True))
+    /// );
+    /// ```
+    ///
     /// Shadowing:
     /// ```rust
     /// use myslip::sexp::{SExp::*, SLeaf::*, util::*};