A class that stores an expression you can execute.
An expression can be made of any arithmetic operation, built-in math function call, method call of a passed instance, or built-in type construction call.
An example expression text using the built-in math functions could be [code]sqrt(pow(3, 2) + pow(4, 2))[/code].
In the following example we use a [LineEdit] node to write our expression and show the result.
[codeblocks]
[gdscript]
var expression = Expression.new()
func _ready():
$LineEdit.text_submitted.connect(self._on_text_submitted)
func _on_text_submitted(command):
var error = expression.parse(command)
if error != OK:
print(expression.get_error_text())
return
var result = expression.execute()
if not expression.has_execute_failed():
$LineEdit.text = str(result)
[/gdscript]
[csharp]
public Expression expression = new Expression();
public override void _Ready()
{
GetNode("LineEdit").TextSubmitted += OnTextEntered;
}
private void OnTextEntered(string command)
{
Error error = expression.Parse(command);
if (error != Error.Ok)
{
GD.Print(expression.GetErrorText());
return;
}
object result = expression.Execute();
if (!expression.HasExecuteFailed())
{
GetNode<LineEdit>("LineEdit").Text = result.ToString();
}
}
[/csharp]
[/codeblocks]
Executes the expression that was previously parsed by [method parse] and returns the result. Before you use the returned object, you should check if the method failed by calling [method has_execute_failed].
If you defined input variables in [method parse], you can specify their values in the inputs array, in the same order.
Returns the error text if [method parse] has failed.
Returns [code]true[/code] if [method execute] has failed.
Parses the expression and returns an [enum Error] code.
You can optionally specify names of variables that may appear in the expression with [param input_names], so that you can bind them when it gets executed.