feat: allow reset var counter on vm

Author: bdeneux

engine/vm.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"io/fs"
 	"strings"
+	"sync/atomic"
 )
 
 type bytecode []instruction
@@ -302,6 +303,10 @@ func (vm *VM) SetUserOutput(s *Stream) {
 	vm.output = s
 }
 
+func (vm *VM) ResetVariableCounter() {
+	atomic.StoreInt64(&varCounter, 1) // Set the varCounter to 1 instead of 0 because NewVariable() will first increment this counter and a global root variable has already been set to 1. (See engine/env.go L3)
+}
+
 // Predicate0 is a predicate of arity 0.
 type Predicate0 func(*VM, Cont, *Env) *Promise