<?xml version="1.0" encoding="UTF-8" ?> <class name="Expression" inherits="RefCounted" version="4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd"> <brief_description> A class that stores an expression you can execute. </brief_description> <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 [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.connect("text_submitted", 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").Connect("text_submitted", this, nameof(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] </description> <tutorials> </tutorials> <methods> <method name="execute"> <return type="Variant" /> <argument index="0" name="inputs" type="Array" default="[]" /> <argument index="1" name="base_instance" type="Object" default="null" /> <argument index="2" name="show_error" type="bool" default="true" /> <description> 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. </description> </method> <method name="get_error_text" qualifiers="const"> <return type="String" /> <description> Returns the error text if [method parse] has failed. </description> </method> <method name="has_execute_failed" qualifiers="const"> <return type="bool" /> <description> Returns [code]true[/code] if [method execute] has failed. </description> </method> <method name="parse"> <return type="int" enum="Error" /> <argument index="0" name="expression" type="String" /> <argument index="1" name="input_names" type="PackedStringArray" default="PackedStringArray()" /> <description> Parses the expression and returns an [enum Error] code. You can optionally specify names of variables that may appear in the expression with [code]input_names[/code], so that you can bind them when it gets executed. </description> </method> </methods> </class>