add equality checking and lt,gt,etc

This commit is contained in:
David 2021-02-14 12:20:34 -05:00
parent 7212f3d9f6
commit 199203e73f
2 changed files with 168 additions and 41 deletions

View File

@ -8,18 +8,138 @@ type Builtins struct{}
// ErrExit is a special sentinel value to cease computation and quit
var ErrExit = fmt.Errorf("exit requested")
// Eq compares TOS and NOS and puts -1 on the stack if they're equal, 0 otherwise.
func (b *Builtins) Eq(s *Stack) func() error {
return func() error {
tos, err := s.Pop()
if err != nil {
return err
}
nos, err := s.Pop()
if err != nil {
return err
}
if tos == nos {
s.Push(-1)
return nil
}
s.Push(0)
return nil
}
}
// NEq compares TOS and NOS and puts -1 on the stack if they're not equal, 0 otherwise.
func (b *Builtins) NEq(s *Stack) func() error {
return func() error {
tos, err := s.Pop()
if err != nil {
return err
}
nos, err := s.Pop()
if err != nil {
return err
}
if tos != nos {
s.Push(-1)
return nil
}
s.Push(0)
return nil
}
}
// Lt compares TOS and NOS and puts -1 on the stack if TOS is less than NOS, 0 otherwise.
func (b *Builtins) Lt(s *Stack) func() error {
return func() error {
tos, err := s.Pop()
if err != nil {
return err
}
nos, err := s.Pop()
if err != nil {
return err
}
if tos < nos {
s.Push(-1)
return nil
}
s.Push(0)
return nil
}
}
// Gt compares TOS and NOS and puts -1 on the stack if TOS is greater than NOS, 0 otherwise.
func (b *Builtins) Gt(s *Stack) func() error {
return func() error {
tos, err := s.Pop()
if err != nil {
return err
}
nos, err := s.Pop()
if err != nil {
return err
}
if tos > nos {
s.Push(-1)
return nil
}
s.Push(0)
return nil
}
}
// LtEq compares TOS and NOS and puts -1 on the stack if TOS is less than or equal to NOS, 0 otherwise.
func (b *Builtins) LtEq(s *Stack) func() error {
return func() error {
tos, err := s.Pop()
if err != nil {
return err
}
nos, err := s.Pop()
if err != nil {
return err
}
if tos <= nos {
s.Push(-1)
return nil
}
s.Push(0)
return nil
}
}
// GtEq compares TOS and NOS and puts -1 on the stack if TOS is greater than or equal to NOS, 0 otherwise.
func (b *Builtins) GtEq(s *Stack) func() error {
return func() error {
tos, err := s.Pop()
if err != nil {
return err
}
nos, err := s.Pop()
if err != nil {
return err
}
if tos >= nos {
s.Push(-1)
return nil
}
s.Push(0)
return nil
}
}
// Add sums the top two numbers on the stack and pushes the result
func (b *Builtins) Add(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
r2, err := s.Pop()
nos, err := s.Pop()
if err != nil {
return err
}
s.Push(r1 + r2)
s.Push(tos + nos)
return nil
}
}
@ -27,15 +147,15 @@ func (b *Builtins) Add(s *Stack) func() error {
// Sub performs NOS - TOS and pushes the result
func (b *Builtins) Sub(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
r2, err := s.Pop()
nos, err := s.Pop()
if err != nil {
return err
}
s.Push(r2 - r1)
s.Push(nos - tos)
return nil
}
}
@ -43,15 +163,15 @@ func (b *Builtins) Sub(s *Stack) func() error {
// Mul multiplies the two numbers on the top of the stack and pushes the result
func (b *Builtins) Mul(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
r2, err := s.Pop()
nos, err := s.Pop()
if err != nil {
return err
}
s.Push(r2 * r1)
s.Push(nos * tos)
return nil
}
}
@ -59,15 +179,15 @@ func (b *Builtins) Mul(s *Stack) func() error {
// Div performs NOS/TOS and pushes the (integer!) result
func (b *Builtins) Div(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
r2, err := s.Pop()
nos, err := s.Pop()
if err != nil {
return err
}
s.Push(r2 / r1)
s.Push(nos / tos)
return nil
}
}
@ -75,11 +195,11 @@ func (b *Builtins) Div(s *Stack) func() error {
// Print pops the stack and outputs it to stdout
func (b *Builtins) Print(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
fmt.Print(r1, " ")
fmt.Print(tos, " ")
return nil
}
}
@ -87,12 +207,12 @@ func (b *Builtins) Print(s *Stack) func() error {
// Dup pops the stack, then pushes two copies onto the stack
func (b *Builtins) Dup(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
s.Push(r1)
s.Push(r1)
s.Push(tos)
s.Push(tos)
return nil
}
}
@ -100,16 +220,16 @@ func (b *Builtins) Dup(s *Stack) func() error {
// Swap inverts the order of TOS and NOS
func (b *Builtins) Swap(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
r2, err := s.Pop()
nos, err := s.Pop()
if err != nil {
return err
}
s.Push(r1)
s.Push(r2)
s.Push(tos)
s.Push(nos)
return nil
}
}
@ -117,17 +237,17 @@ func (b *Builtins) Swap(s *Stack) func() error {
// Over duplicates NOS to TOS, resulting in NOS TOS NOS
func (b *Builtins) Over(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
r2, err := s.Pop()
nos, err := s.Pop()
if err != nil {
return err
}
s.Push(r2)
s.Push(r1)
s.Push(r2)
s.Push(nos)
s.Push(tos)
s.Push(nos)
return nil
}
}
@ -143,21 +263,21 @@ func (b *Builtins) Drop(s *Stack) func() error {
// Rot cycles the first three items on the stack: TOS 1 2 3 -> TOS 3 1 2
func (b *Builtins) Rot(s *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
r2, err := s.Pop()
nos, err := s.Pop()
if err != nil {
return err
}
r3, err := s.Pop()
p3, err := s.Pop()
if err != nil {
return err
}
s.Push(r2)
s.Push(r1)
s.Push(r3)
s.Push(nos)
s.Push(tos)
s.Push(p3)
return err
}
}
@ -175,11 +295,11 @@ func (b *Builtins) Words(d Dictionary) func() error {
// Emit outputs the UTF-8 rune for the int on the top of the stack
func (b *Builtins) Emit(s *Stack) func() error {
return func() error {
i, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
fmt.Print(string(rune(i)) + " ")
fmt.Print(string(rune(tos)) + " ")
return nil
}
}
@ -187,11 +307,11 @@ func (b *Builtins) Emit(s *Stack) func() error {
// ToR pops from the stack to the return stack
func (b *Builtins) ToR(s *Stack, r *Stack) func() error {
return func() error {
r1, err := s.Pop()
tos, err := s.Pop()
if err != nil {
return err
}
r.Push(r1)
r.Push(tos)
return nil
}
}
@ -199,11 +319,11 @@ func (b *Builtins) ToR(s *Stack, r *Stack) func() error {
// RFrom pops from the return stack to the stack
func (b *Builtins) RFrom(s *Stack, r *Stack) func() error {
return func() error {
r1, err := r.Pop()
tors, err := r.Pop()
if err != nil {
return err
}
s.Push(r1)
s.Push(tors)
return nil
}
}
@ -211,12 +331,12 @@ func (b *Builtins) RFrom(s *Stack, r *Stack) func() error {
// RFetch copies from the return stack to the stack
func (b *Builtins) RFetch(s *Stack, r *Stack) func() error {
return func() error {
r1, err := r.Pop()
tors, err := r.Pop()
if err != nil {
return err
}
r.Push(r1)
s.Push(r1)
r.Push(tors)
s.Push(tors)
return nil
}
}

View File

@ -19,6 +19,13 @@ func main() {
dict.AddWord("*", b.Mul(&stack), "")
dict.AddWord("/", b.Div(&stack), "")
dict.AddWord(".", b.Print(&stack), "")
dict.AddWord("=", b.Eq(&stack), "")
dict.AddWord("0=", nil, "0 = ")
dict.AddWord("<>", b.NEq(&stack), "")
dict.AddWord(">", b.Gt(&stack), "")
dict.AddWord("<", b.Lt(&stack), "")
dict.AddWord(">=", b.GtEq(&stack), "")
dict.AddWord("<=", b.LtEq(&stack), "")
dict.AddWord("DUP", b.Dup(&stack), "")
dict.AddWord("SWAP", b.Swap(&stack), "")
dict.AddWord("OVER", b.Over(&stack), "")