Implemented assignments

src/build/VariableDefinition.go

@@ -48,8 +48,3 @@ func (f *Function) CompileVariableDefinition(expr *expression.Expression) error
 
 	return nil
 }
-
-// isVariableDefinition returns true if the expression is a variable definition.
-func isVariableDefinition(expr *expression.Expression) bool {
-	return expr.Token.Kind == token.Operator && expr.Token.Text() == ":="
-}