add rot and swap

1 files changed, 50 insertions, 5 deletions

diff --git a/src/forth/vm.rs b/src/forth/vm.rs
index e4c01f2..7ce9c03 100644
--- a/src/forth/vm.rs
+++ b/src/forth/vm.rs
@@ -18,6 +18,8 @@ pub enum OpCode {
     Div,
     Dup,
     Drop,
+    Swap,
+    Rot,
     EQ,
     GT,
     GTE,
@@ -177,6 +179,20 @@ impl VM {
             OpCode::Drop => {
                 self.stack.0.pop().ok_or(RuntimeError::StackUnderflow)?;
             },
+            OpCode::Swap => {
+                let v1 = self.stack.0.pop().ok_or(RuntimeError::StackUnderflow)?;
+                let v2 = self.stack.0.pop().ok_or(RuntimeError::StackUnderflow)?;
+                self.stack.0.push(v1);
+                self.stack.0.push(v2);
+            },
+            OpCode::Rot => {
+                let v1 = self.stack.0.pop().ok_or(RuntimeError::StackUnderflow)?;
+                let v2 = self.stack.0.pop().ok_or(RuntimeError::StackUnderflow)?;
+                let v3 = self.stack.0.pop().ok_or(RuntimeError::StackUnderflow)?;
+                self.stack.0.push(v2);
+                self.stack.0.push(v1);
+                self.stack.0.push(v3);
+            },
             OpCode::EQ => {
                 let n1 = self.stack.0.pop().ok_or(RuntimeError::StackUnderflow)?;
                 let n2 = self.stack.0.pop().ok_or(RuntimeError::StackUnderflow)?;
@@ -257,6 +273,12 @@ mod tests {
     use super::*;
     use super::OpCode;
 
+    fn wl_for(v: Vec<Vec<OpCode>>) -> WordList {
+        WordList(v.into_iter()
+            .map(|x| ByteCode(x))
+            .collect())
+    }
+
     #[test]
     fn simple_ticks() -> Result<(), RuntimeError> {
         let mut wordlist = WordList(vec![]);
@@ -532,11 +554,12 @@ mod tests {
 
     #[test]
     fn tail_if_else_then_false() -> Result<(), RuntimeError> {
-        let mut wordlist = WordList(vec![]);
-        wordlist.0.push(ByteCode(vec![OpCode::Call(1), OpCode::Num(-2)]));
-        wordlist.0.push(ByteCode(vec![OpCode::Num(0), OpCode::TIf(2, Some(3)), OpCode::Ret]));
-        wordlist.0.push(ByteCode(vec![OpCode::Num(1), OpCode::Ret]));
-        wordlist.0.push(ByteCode(vec![OpCode::Num(2), OpCode::Ret]));
+        let wordlist = WordList(vec![
+            vec![OpCode::Call(1), OpCode::Num(-2)],
+            vec![OpCode::Num(0), OpCode::TIf(2, Some(3)), OpCode::Ret],
+            vec![OpCode::Num(1), OpCode::Ret],
+            vec![OpCode::Num(2), OpCode::Ret],
+        ].into_iter().map(|x| ByteCode(x)).collect());
         let mut vm = VM::new(wordlist);
 
         vm.tick()?;
@@ -554,4 +577,26 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    fn opcode_swap() -> Result<(), RuntimeError> {
+        let wordlist = wl_for(vec![
+            vec![OpCode::Num(1), OpCode::Num(2), OpCode::Swap],
+        ]);
+        let mut vm = VM::new(wordlist);
+        vm.run()?;
+        assert_eq!(vm.stack.0, vec![2, 1]);
+        Ok(())
+    }
+
+    #[test]
+    fn opcode_rot() -> Result<(), RuntimeError> {
+        let wordlist = wl_for(vec![
+            vec![OpCode::Num(1), OpCode::Num(2), OpCode::Num(3), OpCode::Rot],
+        ]);
+        let mut vm = VM::new(wordlist);
+        vm.run()?;
+        assert_eq!(vm.stack.0, vec![2, 3, 1]);
+        Ok(())
+    }
 }