8fb113bb4c
Includes: * Decal * Dictionary * Directory * DisplayServer * DTLSServer * DynamicFont * EditorImportPlugin * EditorPlugin * EditorScenePostImport * EditorScript * EditorSettings * EditorTranslationParserPlugin * Engine * Expression Co-authored-by: Aaron Franke <arnfranke@yahoo.com>
97 lines
3.3 KiB
XML
97 lines
3.3 KiB
XML
<?xml version="1.0" encoding="UTF-8" ?>
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<class name="Expression" inherits="Reference" version="4.0">
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<brief_description>
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A class that stores an expression you can execute.
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</brief_description>
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<description>
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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.
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An example expression text using the built-in math functions could be [code]sqrt(pow(3, 2) + pow(4, 2))[/code].
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In the following example we use a [LineEdit] node to write our expression and show the result.
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[codeblocks]
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[gdscript]
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var expression = Expression.new()
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func _ready():
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$LineEdit.connect("text_entered", self, "_on_text_entered")
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func _on_text_entered(command):
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var error = expression.parse(command)
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if error != OK:
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print(expression.get_error_text())
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return
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var result = expression.execute()
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if not expression.has_execute_failed():
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$LineEdit.text = str(result)
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[/gdscript]
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[csharp]
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public Expression expression = new Expression();
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public override void _Ready()
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{
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GetNode("LineEdit").Connect("text_entered", this, nameof(OnTextEntered));
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}
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private void OnTextEntered(string command)
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{
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Error error = expression.Parse(command);
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if (error != Error.Ok)
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{
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GD.Print(expression.GetErrorText());
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return;
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}
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object result = expression.Execute();
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if (!expression.HasExecuteFailed())
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{
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GetNode<LineEdit>("LineEdit").Text = result.ToString();
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}
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}
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[/csharp]
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[/codeblocks]
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</description>
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<tutorials>
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</tutorials>
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<methods>
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<method name="execute">
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<return type="Variant">
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</return>
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<argument index="0" name="inputs" type="Array" default="[ ]">
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</argument>
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<argument index="1" name="base_instance" type="Object" default="null">
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</argument>
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<argument index="2" name="show_error" type="bool" default="true">
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</argument>
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<description>
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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].
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If you defined input variables in [method parse], you can specify their values in the inputs array, in the same order.
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</description>
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</method>
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<method name="get_error_text" qualifiers="const">
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<return type="String">
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</return>
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<description>
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Returns the error text if [method parse] has failed.
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</description>
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</method>
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<method name="has_execute_failed" qualifiers="const">
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<return type="bool">
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</return>
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<description>
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Returns [code]true[/code] if [method execute] has failed.
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</description>
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</method>
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<method name="parse">
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<return type="int" enum="Error">
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</return>
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<argument index="0" name="expression" type="String">
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</argument>
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<argument index="1" name="input_names" type="PackedStringArray" default="PackedStringArray( )">
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</argument>
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<description>
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Parses the expression and returns an [enum Error] code.
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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.
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</description>
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</method>
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</methods>
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<constants>
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</constants>
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</class>
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