implement boolean primitives; `begin` form

1 files changed, 30 insertions, 1 deletions

diff --git a/src/lisp/env.rs b/src/lisp/env.rs
index 6338f91..c5ff6d3 100644
--- a/src/lisp/env.rs
+++ b/src/lisp/env.rs
@@ -67,7 +67,7 @@ pub fn with_prelude() -> Environment {
             }
         }
     });
-    primitive!(env, Some(1), "and", |args, _| {
+    primitive!(env, Some(2), "and", |args, _| {
         if args
             .iter()
             .any(|arg| matches!(arg, LispExpr::BoolLit(false)))
@@ -77,6 +77,35 @@ pub fn with_prelude() -> Environment {
             Ok(LispExpr::BoolLit(true))
         }
     });
+    primitive!(env, Some(2), "or", |args, _| {
+        if args
+            .iter()
+            .any(|arg| matches!(arg, LispExpr::BoolLit(true)))
+        {
+            Ok(LispExpr::BoolLit(true))
+        } else {
+            Ok(LispExpr::BoolLit(false))
+        }
+    });
+    primitive!(env, Some(1), "not", |args, _| {
+        match args {
+            [val] => {
+                if matches!(val, LispExpr::BoolLit(false)) {
+                    Ok(LispExpr::BoolLit(true))
+                } else {
+                    Ok(LispExpr::BoolLit(false))
+                }
+            }
+            _ => Err(LispError::EvalError),
+        }
+    });
+    primitive!(env, None, "begin", |args, _| {
+        if args.is_empty() {
+            Err(LispError::EvalError)
+        } else {
+            Ok(args.into_iter().last().unwrap().clone())
+        }
+    });
     env
 }