1 files changed, 46 insertions, 0 deletions

diff --git a/src/lisp/mod.rs b/src/lisp/mod.rs
new file mode 100644
index 0000000..5d8965f
--- /dev/null
+++ b/src/lisp/mod.rs
@@ -0,0 +1,46 @@
+use std::fmt;
+
+use number::LispNumber;
+
+mod error;
+mod lex;
+mod number;
+
+#[derive(Debug, PartialEq)]
+pub enum LispExpr {
+    Number(LispNumber),
+    List(Vec<LispExpr>),
+    StringLit(String),
+    BoolLit(bool),
+    Ident(String),
+    Function(LispFunction),
+}
+
+impl fmt::Display for LispExpr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            LispExpr::Number(n) => write!(f, "{}", n)?,
+            LispExpr::List(l) => {
+                for expr in l.iter() {
+                    write!(f, " {} ", expr)?
+                }
+            }
+            LispExpr::StringLit(s) => write!(f, "{:?}", s)?,
+            LispExpr::BoolLit(b) => {
+                if *b {
+                    write!(f, "#t")?
+                } else {
+                    write!(f, "#f")?
+                }
+            }
+            LispExpr::Ident(s) => write!(f, "{}", s)?,
+            LispExpr::Function(_) => write!(f, "<#procedure>")?,
+        };
+        Ok(())
+    }
+}
+
+pub type Environment = Vec<(String, LispExpr)>;
+
+#[derive(Debug, PartialEq)]
+struct LispFunction {}