Early ISA Unit tests

This commit provides some but not all unit tests for VM instructions.
All tests pass, and this commit includes modifications to logic to allow
for that.

Signed-off-by: Ava Affine <ava@sunnypup.io>

.forgejo/workflows/test.yml

@@ -79,4 +79,6 @@ jobs:
         run:  cargo test util
       - name: test garbage collection
         run:  cargo test heap
+      - name: test instruction set implementation
+        run:  cargo test isa_
 

hyphae/instructions.toml

@@ -29,7 +29,7 @@ description = "test if a name is already bound"
 name = "push"
 args = ["operand"]
 output = ""
-description = "pushes operand onto stack."
+description = "pushes deep copy of operand onto stack."
 
 [[instructions]]
 name = "pop"
@@ -50,7 +50,7 @@ output = ""
 description = "delete current stack frame"
 
 [[instructions]]
-name = "load"
+name = "link"
 args = ["src", "dest"]
 output = ""
 description = "shallow copies src into dest"

hyphae/src/heap.rs

@@ -21,6 +21,7 @@ use core::ptr::NonNull;
 use alloc::rc::Rc;
 use alloc::vec::Vec;
 use alloc::boxed::Box;
+use alloc::fmt::Debug;
 use alloc::string::String;
 
 use organelle::Number;
@@ -112,6 +113,15 @@ impl<T> Clone for Gc<T> {
     }
 }
 
+impl<T: Debug> Debug for Gc<T> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        let refs = Rc::strong_count(unsafe { self.0.as_ref() });
+        write!(f, "<refs={refs}>: ")?;
+        write!(f, "{:?}", (*(unsafe { self.0.as_ref() })).as_ref())?;
+        Ok(())
+    }
+}
+
 impl<T> Drop for Gc<T> {
     fn drop(&mut self) {
         unsafe {
@@ -132,7 +142,7 @@ impl<T: Clone> Gc<T> {
     }
 }
 
-#[derive(PartialEq)]
+#[derive(PartialEq, Debug)]
 pub enum Datum {
     Number(Number),
     Bool(bool),
@@ -168,7 +178,7 @@ impl Clone for Datum {
     }
 }
 
-#[derive(Clone, PartialEq)]
+#[derive(Clone, PartialEq, Debug)]
 pub struct Cons(pub Option<Gc<Datum>>, pub Option<Gc<Datum>>);
 
 impl Cons {

hyphae/src/stackstack.rs

@@ -131,10 +131,10 @@ impl<T: Debug> Debug for StackStack<T> {
         let mut ss_idx = 1;
         let mut ss_cur = &*self.0;
         while let Some(inner) = ss_cur {
-            write!(f, "Frame {ss_idx}:")?;
+            write!(f, "Frame {ss_idx}:\n")?;
             let mut s_cur = &*inner.stack.0;
             while let Some(node) = s_cur {
-                write!(f, " {:#?}", node.data)?;
+                write!(f, "  > {:?}\n", node.data)?;
                 s_cur = &*node.next.0;
             }
             write!(f, "\n")?;
@@ -278,4 +278,12 @@ mod tests {
         assert_eq!(g[1], 1);
         assert_eq!(g[2], 0);
     }
+
+    #[test]
+    fn test_stack_idx_zero() {
+        let mut g = StackStack::<i8>::new();
+        g.add_stack();
+        g.push_current_stack(2);
+        assert_eq!(g[0], 2);
+    }
 }

hyphae/src/util.rs

@@ -258,23 +258,23 @@ mod tests {
         assert_eq!(oe_bytes.unwrap(), vec![instr::TRAP.0, 0xf3]);
 
         let two_operands =
-            TryInto::<Instruction>::try_into(&[instr::LOAD.0, 0xf3, 0xf4][..]);
+            TryInto::<Instruction>::try_into(&[instr::LINK.0, 0xf3, 0xf4][..]);
         assert!(two_operands.is_ok());
         let two_oper = two_operands.unwrap();
-        assert_eq!(two_oper.0, instr::LOAD);
+        assert_eq!(two_oper.0, instr::LINK);
         assert_eq!(two_oper.1.len(), 2);
         let two_bytes =
             TryInto::<Vec<u8>>::try_into(two_oper.clone());
         assert!(two_bytes.is_ok());
-        assert_eq!(two_bytes.unwrap(), vec![instr::LOAD.0, 0xf3, 0xf4]);
+        assert_eq!(two_bytes.unwrap(), vec![instr::LINK.0, 0xf3, 0xf4]);
         assert_eq!(two_oper.1[0], Operand(Address::Oper1, 0));
         assert_eq!(two_oper.1[1], Operand(Address::Oper2, 0));
    }
 
     #[test]
     fn test_program_parse() {
-        let bytes1 = [instr::LOAD.0, 0xf3, 0xf4];
+        let bytes1 = [instr::LINK.0, 0xf3, 0xf4];
-        let out1 = vec![Instruction(instr::LOAD,
+        let out1 = vec![Instruction(instr::LINK,
             vec![Operand(Address::Oper1, 0), Operand(Address::Oper2, 0)])];
         let res1 =
             TryInto::<Program>::try_into(&bytes1[..]);
@@ -282,11 +282,11 @@ mod tests {
         assert_eq!(res1.unwrap().0, out1);
 
         let bytes2 = [
-            instr::LOAD.0, 0xf3, 0xf4,
+            instr::LINK.0, 0xf3, 0xf4,
             instr::CLEAR.0, 0xf0, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
         ];
         let out2 = vec![
-            Instruction(instr::LOAD, vec![
+            Instruction(instr::LINK, vec![
                 Operand(Address::Oper1, 0),
                 Operand(Address::Oper2, 0)
             ]),

hyphae/src/vm.rs

@@ -62,7 +62,7 @@ pub struct VM {
 impl From<Program> for VM {
     fn from(value: Program) -> Self {
         VM{
-            stack: StackStack::new(),
+            stack: StackStack::<Gc<Datum>>::new(),
             symtab: QuickMap::new(),
             prog: value,
             traps: vec![],
@@ -143,8 +143,6 @@ impl VM {
 
     #[inline(always)]
     fn execute_instruction(&mut self) {
-        let instr = &self.prog.0[self.ictr].clone();
-
         macro_rules! e {
             ( $err:expr ) => {
                 {
@@ -156,6 +154,11 @@ impl VM {
             }
         }
 
+        if self.ictr > self.prog.0.len() {
+            e!("attempt to execute out of bounds instruction");
+        }
+        let instr = &self.prog.0[self.ictr].clone();
+
         // get or set according to addressing mode
         macro_rules! access {
             ( $oper:expr ) => {
@@ -193,7 +196,7 @@ impl VM {
                     e!("out of bounds jump caught");
                 }
 
-               self.ictr = target;
+               self.ictr = target - 1; // will post increment in calling func
             }
         }
 
@@ -244,18 +247,18 @@ impl VM {
                     e!("illegal argument to BOUND instruction");
                 };
                 let tag = unsafe { str::from_utf8_unchecked(tag) };
-                self.symtab.contains_key(tag);
+                self.expr = Datum::Bool(self.symtab.contains_key(tag)).into();
             },
 
             // stack ops
             i::PUSH => self.stack.push_current_stack(
-                access!(&instr.1[0]).clone()),
+                access!(&instr.1[0]).deep_copy()),
             i::POP => _ = self.stack.pop_current_stack(),
             i::ENTER => self.stack.add_stack(),
             i::EXIT => self.stack.destroy_top_stack(),
 
             // movement ops
-            i::LOAD => access!(&instr.1[1], access!(&instr.1[0]).clone()),
+            i::LINK => access!(&instr.1[1], access!(&instr.1[0]).clone()),
             i::DUPL => access!(&instr.1[1], access!(&instr.1[0]).deep_copy()),
             i::CLEAR => access!(&instr.1[0], Datum::None.into()),
 
@@ -368,7 +371,7 @@ impl VM {
                 if let Datum::Char(schr) = **access!(&instr.1[0]) {
                     Datum::Number(Number::Fra(Fraction(schr as isize, 1))).into()
                 } else {
-                    e!("illegal argument to INC instruction");
+                    e!("illegal argument to CTON instruction");
                 }
             }),
 
@@ -381,7 +384,7 @@ impl VM {
                         }
                     Datum::Char(n.0.trunc() as u64 as u8).into()
                 } else {
-                    e!("illegal argument to INC instruction");
+                    e!("illegal argument to NTOC instruction");
                 }
             }),
 
@@ -402,7 +405,7 @@ impl VM {
             },
 
             i::CONST => access!(&instr.1[0], {
-                let Operand(Address::Numer, num) = instr.1[0] else {
+                let Operand(Address::Numer, num) = instr.1[1] else {
                     e!("illegal argument to CONST instruction");
                 };
 
@@ -588,123 +591,14 @@ impl VM {
 
 #[cfg(test)]
 mod tests {
-    use core::array;
     use super::*;
-    use crate::instr;
+    use crate::instr as i;
-
+    use crate::util::{Program, Instruction, Operand};
-    const ISA_TESTS: [Option<Vec<(VM, TestResult)>>; instr::TOTAL_INSTRUCTIONS] = [
+    use core::ops::Deref;
-        // TRAP
+    use organelle::Float;
-        None,
-        // BIND
-        None,
-        // UNBIND
-        None,
-        // BOUND
-        None,
-        // PUSH
-        None,
-        // POP
-        None,
-        // ENTER
-        None,
-        // EXIT
-        None,
-        // LOAD
-        None,
-        // DUPL
-        None,
-        // CLEAR
-        None,
-        // NOP
-        None,
-        // HALT
-        None,
-        // PANIC
-        None,
-        // JMP
-        None,
-        // JMPIF
-        None,
-        // EQ
-        None,
-        // LT
-        None,
-        // GT
-        None,
-        // LTE
-        None,
-        // GTE
-        None,
-        // BOOL_NOT
-        None,
-        // BOOL_AND
-        None,
-        // BOOL_OR
-        None,
-        // BYTE_AND
-        None,
-        // BYTE_OR
-        None,
-        // XOR
-        None,
-        // BYTE_NOT
-        None,
-        // ADD
-        None,
-        // SUB
-        None,
-        // MUL
-        None,
-        // FDIV
-        None,
-        // IDIV
-        None,
-        // POW
-        None,
-        // MODULO
-        None,
-        // REM
-        None,
-        // INC
-        None,
-        // DEC
-        None,
-        // CTON
-        None,
-        // NTOC
-        None,
-        // NTOI
-        None,
-        // NTOE
-        None,
-        // CONST
-        None,
-        // MKVEC
-        None,
-        // MKBVEC
-        None,
-        // INDEX
-        None,
-        // LENGTH
-        None,
-        // SUBSL
-        None,
-        // INSER
-        None,
-        // CONS
-        None,
-        // CAR
-        None,
-        // CDR
-        None,
-        // CONCAT
-        None,
-        // S_APPEND
-        None,
-    ];
 
     fn has_stack(state: &VM, idx: usize, target: Gc<Datum>) -> bool {
-        *(state.stack[idx]) == *target
+        state.stack[idx].deref() == target.deref()
     }
 
     fn has_sym(state: &VM, sym: &str, operand: Option<Operand>) -> bool {
@@ -723,16 +617,28 @@ mod tests {
 
     impl TestResult {
         fn chk_expr(&self, state: &VM) -> bool {
-            self.expr.is_none() || *(state.expr) == *(self.expr.clone().unwrap())
+            if *(state.expr) == *(self.expr.clone().unwrap()) {
+                true
+            } else {
+                print!("expecting expr: {:?}\n", self.expr);
+                print!("has expr: {:?}\n", state.expr);
+                false
+            }
         }
 
         fn chk_err(&self, state: &VM) -> bool {
             if let Datum::String(ref msg) = *state.errr {
                 let msg = unsafe { str::from_utf8_unchecked(msg) };
-                msg == self.errr.unwrap()
+                if msg == self.errr.unwrap() {
-            } else if let Datum::None = *state.errr {
+                    true
-                self.errr.is_none()
                 } else {
+                    print!("expected error {:?}, got {:?}\n", self.errr, msg);
+                    false
+                }
+            } else if let Datum::None = *state.errr && self.errr.is_none(){
+                true
+            } else {
+                print!("expected error {:?}, got {:?}\n", self.errr, state.errr);
                 false
             }
         }
@@ -740,6 +646,9 @@ mod tests {
         fn chk_stack(&self, state: &VM) -> bool {
             for i in &self.stack {
                 if !has_stack(&state, i.0, i.1.clone()) {
+                    print!("expected stack to have {:?} at {}\n", *i.1, i.0);
+                    print!("instead has {:?}\n", state.stack[i.0].deref());
+                    print!("\nfull stack:\n{:#?}\n", state.stack);
                     return false
                 }
             }
@@ -749,33 +658,492 @@ mod tests {
         fn chk_syms(&self, state: &VM) -> bool {
             for i in &self.syms {
                 if !has_sym(&state, i.0, i.1.clone()) {
+                    print!("expected symbol {} == {:?}\n", i.0, i.1.clone());
+                    print!("instead has {:?}\n", state.symtab.get(&i.0.to_owned()));
                     return false
                 }
             }
             true
         }
 
-        fn test_passes(&self, state: VM) -> bool {
+        fn test_passes(&self, state: &VM) -> bool {
+                                      self.chk_err(&state)    &&
             (self.expr.is_none()   || self.chk_expr(&state))  &&
             (self.stack.is_empty() || self.chk_stack(&state)) &&
-            (self.syms.is_empty()  || self.chk_syms(&state))  &&
+            (self.syms.is_empty()  || self.chk_syms(&state))
-            (self.errr.is_none()   || self.chk_err(&state))
         }
     }
 
     #[test]
-    fn run_isa_tests() {
+    fn isa_trap_tests() {
-        for i in &ISA_TESTS.to_vec() {
+        let mut vm = VM::from(Program(vec![
-            let Some(test_case) = i else {
+            Instruction(i::TRAP, vec![Operand(Address::Numer, 0)])
-                assert!(false); // dont let untested instructions happen
+        ])).with_traps(Some(vec![
-                return
+            Arc::from(|state: &mut VM| {
+                state.expr = Datum::Bool(true).into()
+            })
+        ])).to_owned();
+
+        let case = TestResult{
+            expr: Some(Datum::Bool(true).into()),
+            stack: vec![],
+            syms: vec![],
+            errr: None,
         };
 
-            for i in test_case {
-                let (mut vm, result) = (i.0.clone(), i.1.clone());
         vm.run_program();
-                assert!(result.test_passes(vm));
+        assert!(case.test_passes(&vm));
-            }
+    }
-        }
+
+    #[test]
+    fn isa_symtable_tests() {
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::BIND, vec![Operand(Address::Stack, 1),
+                                      Operand(Address::Stack, 0)]),
+        ])).with_stack(Some({
+            let mut i = StackStack::<Gc<Datum>>::new();
+            i.push_current_stack(Datum::String("test".into()).into());
+            i.push_current_stack(Datum::String("value".into()).into());
+            i
+       })).to_owned();
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![
+                (1, Datum::String("test".into()).into()),
+                (0, Datum::String("value".into()).into()),
+            ],
+            syms: vec![("test", Some(Operand(Address::Stack, 0)))],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::BIND, vec![Operand(Address::Stack, 1),
+                                      Operand(Address::Stack, 0)]),
+            Instruction(i::BOUND, vec![Operand(Address::Stack, 1)])
+        ])).with_stack(Some({
+            let mut i = StackStack::<Gc<Datum>>::new();
+            i.push_current_stack(Datum::String("test".into()).into());
+            i.push_current_stack(Datum::String("value".into()).into());
+            i
+        })).to_owned();
+
+        let case = TestResult{
+            expr: Some(Datum::Bool(true).into()),
+            stack: vec![
+                (1, Datum::String("test".into()).into()),
+                (0, Datum::String("value".into()).into()),
+            ],
+            syms: vec![("test", Some(Operand(Address::Stack, 0)))],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::BIND, vec![Operand(Address::Stack, 1),
+                                      Operand(Address::Stack, 0)]),
+            Instruction(i::UNBIND, vec![Operand(Address::Stack, 1)])
+        ])).with_stack(Some({
+            let mut i = StackStack::<Gc<Datum>>::new();
+            i.push_current_stack(Datum::String("test".into()).into());
+            i.push_current_stack(Datum::String("value".into()).into());
+            i
+        })).to_owned();
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![
+                (1, Datum::String("test".into()).into()),
+                (0, Datum::String("value".into()).into()),
+            ],
+            syms: vec![("test", None)],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+    }
+
+    #[test]
+    fn isa_stack_tests() {
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 4)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr,  0)])
+        ]));
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![
+                (0, Datum::Number(Number::Fra(Fraction(4, 1))).into())
+            ],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+       let mut vm = VM::from(Program(vec![
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 4)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr,  0)]),
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 5)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr,  0)]),
+            Instruction(i::POP,   vec![])
+        ]));
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![
+                (0, Datum::Number(Number::Fra(Fraction(4, 1))).into())
+            ],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 4)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr,  0)]),
+            Instruction(i::ENTER, vec![]),
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 5)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr,  0)]),
+        ]));
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![
+                (1, Datum::Number(Number::Fra(Fraction(4, 1))).into()),
+                (0, Datum::Number(Number::Fra(Fraction(5, 1))).into())
+            ],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 4)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr,  0)]),
+            Instruction(i::ENTER, vec![]),
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 5)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr,  0)]),
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 5)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr,  0)]),
+            Instruction(i::EXIT,  vec![]),
+        ]));
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![
+                (0, Datum::Number(Number::Fra(Fraction(4, 1))).into()),
+            ],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+    }
+
+    #[test]
+    fn isa_load_dupl_clear() {
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::CONST, vec![Operand(Address::Expr, 0),
+                                       Operand(Address::Numer, 4)]),
+            Instruction(i::LINK,  vec![Operand(Address::Expr, 0),
+                                       Operand(Address::Oper1, 0)]),
+            Instruction(i::DUPL,  vec![Operand(Address::Expr, 0),
+                                       Operand(Address::Oper2, 0)]),
+            Instruction(i::INC,   vec![Operand(Address::Oper2, 0)]),
+            Instruction(i::CLEAR, vec![Operand(Address::Expr, 0)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Oper1, 0)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Oper2, 0)]),
+        ]));
+
+        let case = TestResult{
+            expr: Some(Datum::None.into()),
+            stack: vec![
+                (1, Datum::Number(Number::Fra(Fraction(4, 1))).into()),
+                (0, Datum::Number(Number::Fra(Fraction(5, 1))).into())
+            ],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+    }
+
+    #[test]
+    fn isa_nop_halt_panic() {
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::NOP, vec![])
+        ]));
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::HALT, vec![]),
+            Instruction(i::PUSH, vec![Operand(Address::Numer, 1)])
+        ]));
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::PANIC, vec![Operand(Address::Stack, 0)])
+        ])).with_stack({
+            let mut i = StackStack::<Gc<Datum>>::new();
+            i.push_current_stack(Datum::String("testerr".into()).into());
+            Some(i)
+        }).to_owned();
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![],
+            syms: vec![],
+            errr: Some("testerr"),
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+    }
+
+    #[test]
+    fn isa_inc_dec() {
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 4)]),
+            Instruction(i::INC,   vec![Operand(Address::Expr,  0)]),
+        ]));
+
+        let case = TestResult{
+            expr: Some(Datum::Number(Number::Fra(Fraction(5, 1))).into()),
+            stack: vec![],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 4)]),
+            Instruction(i::DEC,   vec![Operand(Address::Expr,  0)]),
+        ]));
+
+        let case = TestResult{
+            expr: Some(Datum::Number(Number::Fra(Fraction(3, 1))).into()),
+            stack: vec![],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+    }
+
+    #[test]
+    fn isa_jmp_jmpif() {
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::JMP,   vec![Operand(Address::Instr, 2)]),
+            Instruction(i::HALT,  vec![]),
+            Instruction(i::CONST, vec![Operand(Address::Expr, 0),
+                                       Operand(Address::Numer, 3)]),
+        ]));
+
+        let case = TestResult{
+            expr: Some(Datum::Number(Number::Fra(Fraction(3, 1))).into()),
+            stack: vec![],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::LINK,  vec![Operand(Address::Stack, 0),
+                                       Operand(Address::Expr,  0)]),
+            Instruction(i::JMPIF, vec![Operand(Address::Instr, 3)]),
+            Instruction(i::HALT,  vec![]),
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 3)]),
+        ])).with_stack({
+            let mut i = StackStack::new();
+            i.push_current_stack(Datum::Bool(true).into());
+            Some(i)
+        }).to_owned();
+
+        let case = TestResult{
+            expr: Some(Datum::Number(Number::Fra(Fraction(3, 1))).into()),
+            stack: vec![],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::LINK,  vec![Operand(Address::Stack, 0),
+                                       Operand(Address::Expr,  0)]),
+            Instruction(i::JMPIF, vec![Operand(Address::Instr, 3)]),
+            Instruction(i::HALT,  vec![]),
+            Instruction(i::CONST, vec![Operand(Address::Expr,  0),
+                                       Operand(Address::Numer, 3)]),
+        ])).with_stack({
+            let mut i = StackStack::new();
+            i.push_current_stack(Datum::Bool(false).into());
+            Some(i)
+        }).to_owned();
+
+        let case = TestResult{
+            expr: Some(Datum::Bool(false).into()),
+            stack: vec![],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+
+        let mut vm = VM::from(Program(vec![
+            Instruction(i::JMP, vec![Operand(Address::Instr, 300)]),
+        ])).with_stack({
+            let mut i = StackStack::new();
+            i.push_current_stack(Datum::Bool(false).into());
+            Some(i)
+        }).to_owned();
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![],
+            syms: vec![],
+            errr: Some("out of bounds jump caught"),
+        };
+
+        vm.run_program();
+        print!("cur: {}\n", vm.ictr);
+        assert!(case.test_passes(&vm));
+    }
+
+    #[test]
+    fn isa_conversions() {
+        /* program:
+         * dupl %0, $ex
+         * cton $ex
+         * push $ex
+         * ntoc $ex
+         * push $ex
+         * ntoi $ex
+         * push $ex
+         * ntoe $ex
+         * push $ex
+         */
+
+        let mut vm = VM::from(Program(vec![
+            // load from stack into expr
+            Instruction(i::DUPL,  vec![Operand(Address::Stack, 0),
+                                       Operand(Address::Expr,  0)]),
+
+            // create a number and push to stack
+            Instruction(i::CTON,  vec![Operand(Address::Expr, 0)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
+
+            // convert to inexact and push to stack
+            Instruction(i::NTOI,  vec![Operand(Address::Expr, 0)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
+
+            // convert back to exact and push to stack
+            Instruction(i::NTOE,  vec![Operand(Address::Expr, 0)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
+
+            // create a char and push to stack
+            Instruction(i::NTOC,  vec![Operand(Address::Expr, 0)]),
+            Instruction(i::PUSH,  vec![Operand(Address::Expr, 0)]),
+        ])).with_stack({
+            let mut i = StackStack::new();
+            i.push_current_stack(Datum::Char(b'a').into());
+            Some(i)
+        }).to_owned();
+
+        let case = TestResult{
+            expr: None,
+            stack: vec![
+                (0, Datum::Char(b'a').into()),
+                (1, Datum::Number(Number::Fra(Fraction(97, 1))).into()),
+                (2, Datum::Number(Number::Flt(Float(97.0))).into()),
+                (3, Datum::Number(Number::Fra(Fraction(97, 1))).into()),
+                (4, Datum::Char(b'a').into()),
+            ],
+            syms: vec![],
+            errr: None,
+        };
+
+        vm.run_program();
+        assert!(case.test_passes(&vm));
+    }
+
+    #[test]
+    fn isa_index() {
+        // TODO INDEX on V, BV, S, L
+    }
+
+    #[test]
+    fn isa_length() {
+        // TODO LENGTH on V, BV, S, L
+    }
+
+    #[test]
+    fn isa_subsl() {
+        // TODO SUBSL on V, BV, S, L
+    }
+
+    #[test]
+    fn isa_inser() {
+        // TODO INSER on V, BV, S, L
+    }
+
+    #[test]
+    fn isa_cons_ops() {
+        // TODO CAR and CDR and CONS
+    }
+
+    #[test]
+    fn isa_string_ops() {
+        // TODO CONCAT and S_APPEND
     }
 }