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89 lines
3.3 KiB
XML
89 lines
3.3 KiB
XML
<?xml version="1.0" encoding="UTF-8" ?>
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<class name="Expression" inherits="RefCounted" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
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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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$LineEdit.text_submitted.connect(self._on_text_submitted)
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func _on_text_submitted(command):
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var error = expression.parse(command)
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if error != OK:
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print(expression.get_error_text())
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return
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var result = expression.execute()
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if not expression.has_execute_failed():
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$LineEdit.text = str(result)
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[/gdscript]
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[csharp]
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private Expression _expression = new Expression();
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public override void _Ready()
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{
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GetNode<LineEdit>("LineEdit").TextSubmitted += 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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Variant 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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<link title="Evaluating Expressions">$DOCS_URL/tutorials/scripting/evaluating_expressions.html</link>
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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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<param index="0" name="inputs" type="Array" default="[]" />
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<param index="1" name="base_instance" type="Object" default="null" />
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<param index="2" name="show_error" type="bool" default="true" />
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<param index="3" name="const_calls_only" type="bool" default="false" />
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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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<description>
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Returns the error text if [method parse] or [method execute] 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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<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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<param index="0" name="expression" type="String" />
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<param index="1" name="input_names" type="PackedStringArray" default="PackedStringArray()" />
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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 [param input_names], 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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</class>
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