mirror of
https://github.com/godotengine/godot-docs.git
synced 2025-12-31 17:49:03 +03:00
163 lines
7.7 KiB
ReStructuredText
163 lines
7.7 KiB
ReStructuredText
:github_url: hide
|
|
|
|
.. DO NOT EDIT THIS FILE!!!
|
|
.. Generated automatically from Godot engine sources.
|
|
.. Generator: https://github.com/godotengine/godot/tree/master/doc/tools/make_rst.py.
|
|
.. XML source: https://github.com/godotengine/godot/tree/master/doc/classes/Expression.xml.
|
|
|
|
.. _class_Expression:
|
|
|
|
Expression
|
|
==========
|
|
|
|
**Inherits:** :ref:`RefCounted<class_RefCounted>` **<** :ref:`Object<class_Object>`
|
|
|
|
A class that stores an expression you can execute.
|
|
|
|
.. rst-class:: classref-introduction-group
|
|
|
|
Description
|
|
-----------
|
|
|
|
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 ``sqrt(pow(3, 2) + pow(4, 2))``.
|
|
|
|
In the following example we use a :ref:`LineEdit<class_LineEdit>` node to write our expression and show the result.
|
|
|
|
|
|
.. tabs::
|
|
|
|
.. code-tab:: 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)
|
|
|
|
.. code-tab:: csharp
|
|
|
|
private Expression _expression = new Expression();
|
|
|
|
public override void _Ready()
|
|
{
|
|
GetNode<LineEdit>("LineEdit").TextSubmitted += OnTextEntered;
|
|
}
|
|
|
|
private void OnTextEntered(string command)
|
|
{
|
|
Error error = _expression.Parse(command);
|
|
if (error != Error.Ok)
|
|
{
|
|
GD.Print(_expression.GetErrorText());
|
|
return;
|
|
}
|
|
Variant result = _expression.Execute();
|
|
if (!_expression.HasExecuteFailed())
|
|
{
|
|
GetNode<LineEdit>("LineEdit").Text = result.ToString();
|
|
}
|
|
}
|
|
|
|
|
|
|
|
.. rst-class:: classref-introduction-group
|
|
|
|
Tutorials
|
|
---------
|
|
|
|
- :doc:`Evaluating Expressions <../tutorials/scripting/evaluating_expressions>`
|
|
|
|
.. rst-class:: classref-reftable-group
|
|
|
|
Methods
|
|
-------
|
|
|
|
.. table::
|
|
:widths: auto
|
|
|
|
+---------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|
|
| :ref:`Variant<class_Variant>` | :ref:`execute<class_Expression_method_execute>`\ (\ inputs\: :ref:`Array<class_Array>` = [], base_instance\: :ref:`Object<class_Object>` = null, show_error\: :ref:`bool<class_bool>` = true, const_calls_only\: :ref:`bool<class_bool>` = false\ ) |
|
|
+---------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|
|
| :ref:`String<class_String>` | :ref:`get_error_text<class_Expression_method_get_error_text>`\ (\ ) |const| |
|
|
+---------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|
|
| :ref:`bool<class_bool>` | :ref:`has_execute_failed<class_Expression_method_has_execute_failed>`\ (\ ) |const| |
|
|
+---------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|
|
| :ref:`Error<enum_@GlobalScope_Error>` | :ref:`parse<class_Expression_method_parse>`\ (\ expression\: :ref:`String<class_String>`, input_names\: :ref:`PackedStringArray<class_PackedStringArray>` = PackedStringArray()\ ) |
|
|
+---------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|
|
|
|
.. rst-class:: classref-section-separator
|
|
|
|
----
|
|
|
|
.. rst-class:: classref-descriptions-group
|
|
|
|
Method Descriptions
|
|
-------------------
|
|
|
|
.. _class_Expression_method_execute:
|
|
|
|
.. rst-class:: classref-method
|
|
|
|
:ref:`Variant<class_Variant>` **execute**\ (\ inputs\: :ref:`Array<class_Array>` = [], base_instance\: :ref:`Object<class_Object>` = null, show_error\: :ref:`bool<class_bool>` = true, const_calls_only\: :ref:`bool<class_bool>` = false\ ) :ref:`🔗<class_Expression_method_execute>`
|
|
|
|
Executes the expression that was previously parsed by :ref:`parse()<class_Expression_method_parse>` and returns the result. Before you use the returned object, you should check if the method failed by calling :ref:`has_execute_failed()<class_Expression_method_has_execute_failed>`.
|
|
|
|
If you defined input variables in :ref:`parse()<class_Expression_method_parse>`, you can specify their values in the inputs array, in the same order.
|
|
|
|
.. rst-class:: classref-item-separator
|
|
|
|
----
|
|
|
|
.. _class_Expression_method_get_error_text:
|
|
|
|
.. rst-class:: classref-method
|
|
|
|
:ref:`String<class_String>` **get_error_text**\ (\ ) |const| :ref:`🔗<class_Expression_method_get_error_text>`
|
|
|
|
Returns the error text if :ref:`parse()<class_Expression_method_parse>` or :ref:`execute()<class_Expression_method_execute>` has failed.
|
|
|
|
.. rst-class:: classref-item-separator
|
|
|
|
----
|
|
|
|
.. _class_Expression_method_has_execute_failed:
|
|
|
|
.. rst-class:: classref-method
|
|
|
|
:ref:`bool<class_bool>` **has_execute_failed**\ (\ ) |const| :ref:`🔗<class_Expression_method_has_execute_failed>`
|
|
|
|
Returns ``true`` if :ref:`execute()<class_Expression_method_execute>` has failed.
|
|
|
|
.. rst-class:: classref-item-separator
|
|
|
|
----
|
|
|
|
.. _class_Expression_method_parse:
|
|
|
|
.. rst-class:: classref-method
|
|
|
|
:ref:`Error<enum_@GlobalScope_Error>` **parse**\ (\ expression\: :ref:`String<class_String>`, input_names\: :ref:`PackedStringArray<class_PackedStringArray>` = PackedStringArray()\ ) :ref:`🔗<class_Expression_method_parse>`
|
|
|
|
Parses the expression and returns an :ref:`Error<enum_@GlobalScope_Error>` code.
|
|
|
|
You can optionally specify names of variables that may appear in the expression with ``input_names``, so that you can bind them when it gets executed.
|
|
|
|
.. |virtual| replace:: :abbr:`virtual (This method should typically be overridden by the user to have any effect.)`
|
|
.. |const| replace:: :abbr:`const (This method has no side effects. It doesn't modify any of the instance's member variables.)`
|
|
.. |vararg| replace:: :abbr:`vararg (This method accepts any number of arguments after the ones described here.)`
|
|
.. |constructor| replace:: :abbr:`constructor (This method is used to construct a type.)`
|
|
.. |static| replace:: :abbr:`static (This method doesn't need an instance to be called, so it can be called directly using the class name.)`
|
|
.. |operator| replace:: :abbr:`operator (This method describes a valid operator to use with this type as left-hand operand.)`
|
|
.. |bitfield| replace:: :abbr:`BitField (This value is an integer composed as a bitmask of the following flags.)`
|
|
.. |void| replace:: :abbr:`void (No return value.)`
|