virtualx-engine-docs/_sources/classes/class_expression.rst.txt
2024-10-23 09:41:33 -07:00

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.. DO NOT EDIT THIS FILE!!!
.. Generated automatically from Godot engine sources.
.. Generator: https://github.com/godotengine/godot/tree/3.6/doc/tools/make_rst.py.
.. XML source: https://github.com/godotengine/godot/tree/3.6/doc/classes/Expression.xml.
.. _class_Expression:
Expression
==========
**Inherits:** :ref:`Reference<class_Reference>` **<** :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.
::
onready var expression = Expression.new()
func _ready():
$LineEdit.connect("text_entered", self, "_on_text_entered")
func _on_text_entered(command):
var error = expression.parse(command, [])
if error != OK:
print(expression.get_error_text())
return
var result = expression.execute([], null, true)
if not expression.has_execute_failed():
$LineEdit.text = str(result)
.. rst-class:: classref-reftable-group
Methods
-------
.. table::
:widths: auto
+---------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| :ref:`Variant<class_Variant>` | :ref:`execute<class_Expression_method_execute>` **(** :ref:`Array<class_Array>` inputs=[ ], :ref:`Object<class_Object>` base_instance=null, :ref:`bool<class_bool>` show_error=true **)** |
+---------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| :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>` **(** :ref:`String<class_String>` expression, :ref:`PoolStringArray<class_PoolStringArray>` input_names=PoolStringArray( ) **)** |
+---------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
.. 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** **(** :ref:`Array<class_Array>` inputs=[ ], :ref:`Object<class_Object>` base_instance=null, :ref:`bool<class_bool>` show_error=true **)**
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|
Returns the error text if :ref:`parse<class_Expression_method_parse>` 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|
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** **(** :ref:`String<class_String>` expression, :ref:`PoolStringArray<class_PoolStringArray>` input_names=PoolStringArray( ) **)**
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.)`
.. |static| replace:: :abbr:`static (This method doesn't need an instance to be called, so it can be called directly using the class name.)`