func Updatex(vm *gelo.VM, args *gelo.List, ac uint) gelo.Word {
if ac != 2 {
gelo.ArgumentError(vm, "update!", "name value", args)
}
toreset := args.Value
val := args.Next.Value
if !vm.Ns.Mutate(toreset, val) {
gelo.VariableUndefined(vm, toreset)
}
return val
}
func Unsetx(vm *gelo.VM, args *gelo.List, ac uint) gelo.Word {
if ac == 0 {
gelo.ArgumentError(vm, "unset!", "name+", args)
}
return args.MapOrApply(func(w gelo.Word) gelo.Word {
val, ok := vm.Ns.Del(w)
if !ok {
gelo.VariableUndefined(vm, w)
}
return val
})
}
func Swapx(vm *gelo.VM, args *gelo.List, ac uint) gelo.Word {
if ac != 2 {
gelo.ArgumentError(vm, "swap!", "name name", args)
}
fst, snd := args.Value, args.Next.Value
sndw, _, ok := vm.Ns.Swap(fst, snd) //don't need fstw
if !ok {
//we've lost our locks so this may produce nonsense
_, fstb := vm.Ns.Lookup(fst)
_, sndb := vm.Ns.Lookup(snd)
if fstb && sndb {
gelo.RuntimeError(vm, "Neither", fst, "nor", snd, "are defined")
}
if fstb {
gelo.VariableUndefined(vm, fst)
}
if sndb {
gelo.VariableUndefined(vm, snd)
}
gelo.RuntimeError(vm, "swap failed but both operands were defined")
}
return sndw //returned because this is now the "closest"
}
func Decrx(vm *gelo.VM, args *gelo.List, ac uint) gelo.Word {
if ac != 1 {
gelo.ArgumentError(vm, "decr!", "reference to number", args)
}
n, ok := vm.Ns.MutateBy(args.Value,
func(w gelo.Word) (gelo.Word, bool) {
n := vm.API.NumberOrElse(w)
return gelo.NewNumber(n.Real() - 1), true
})
if !ok {
gelo.VariableUndefined(vm, args.Value)
}
return n
}