neo-go/pkg/vm/vm_ops_exceptions.go
2019-03-16 22:08:35 +00:00

33 lines
748 B
Go

package vm
import (
"errors"
"github.com/CityOfZion/neo-go/pkg/vm/stack"
)
// vm exceptions
// THROWIFNOT faults if the item on the top of the stack
// does not evaluate to true
// For specific logic on how a number of bytearray is evaluated can be seen
// from the boolean conversion methods on the stack items
func THROWIFNOT(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation) (Vmstate, error) {
// Pop item from top of stack
item, err := ctx.Estack.Pop()
if err != nil {
return FAULT, err
}
// Convert to a boolean
ok, err := item.Boolean()
if err != nil {
return FAULT, err
}
// If false, throw
if !ok.Value() {
return FAULT, errors.New("Item on top of stack evaluates to false")
}
return NONE, nil
}