Added vectors and tests for their evaluation and typing

3 files changed, 20 insertions, 0 deletions

diff --git a/src/sexp/display.rs b/src/sexp/display.rs
index 96ce435..57d1b50 100644
--- a/src/sexp/display.rs
+++ b/src/sexp/display.rs
@@ -26,6 +26,7 @@ impl fmt::Display for SLeaf {
             Int(x) => x.to_string(),
             Var(s) => s.to_string(),
             Quote  => "quote".to_string(),
+            Vector => "vector".to_string(),
             Nil    => "()".to_string(),
         })
     }
diff --git a/src/sexp/mod.rs b/src/sexp/mod.rs
index 60dd3b0..3f17b79 100644
--- a/src/sexp/mod.rs
+++ b/src/sexp/mod.rs
@@ -27,7 +27,9 @@ pub enum SLeaf {
     Or,
     Not,
     Xor,
+
     Quote,
+    Vector,
 
     Int(i32),
     True,
diff --git a/src/sexp/step.rs b/src/sexp/step.rs
index d66b1bd..535b183 100644
--- a/src/sexp/step.rs
+++ b/src/sexp/step.rs
@@ -220,6 +220,23 @@ impl SExp {
     ///     Ok(scons(Quote, scons(1, scons(2, Nil))))
     /// );
     /// ```
+    ///
+    /// **Vectors**
+    ///
+    /// The same as quotes functionally, but they require
+    /// the elements to be of the same type.
+    /// ```rust
+    /// use myslip::sexp::{SExp::*, SLeaf::*, util::*};
+    /// assert_eq!(
+    ///     scons(Vector, scons(1, scons(2, Nil))).step(),
+    ///     Ok(scons(Vector, scons(1, scons(2, Nil))))
+    /// );
+    /// assert_eq!(
+    ///     scons(Vector, scons(
+    ///         scons(Sub, scons(2, scons(1, Nil))),
+    ///     scons(2, Nil))).step(),
+    ///     Ok(scons(Vector, scons(1, scons(2, Nil))))
+    /// );
     pub fn step(self) -> Result<Self, String> {
         match self {