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<?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>
<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.
[codeblock]
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:
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print(expression.get_error_text())
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return
var result = expression.execute([], null, true)
if not expression.has_execute_failed():
$LineEdit.text = str(result)
[/codeblock]
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</description>
<tutorials >
</tutorials>
<methods >
<method name= "execute" >
<return type= "Variant" >
</return>
<argument index= "0" name= "inputs" type= "Array" default= "[ ]" >
</argument>
<argument index= "1" name= "base_instance" type= "Object" default= "null" >
</argument>
<argument index= "2" name= "show_error" type= "bool" default= "true" >
</argument>
<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>
</method>
<method name= "get_error_text" qualifiers= "const" >
<return type= "String" >
</return>
<description >
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Returns the error text if [method parse] has failed.
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</description>
</method>
<method name= "has_execute_failed" qualifiers= "const" >
<return type= "bool" >
</return>
<description >
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Returns [code]true[/code] if [method execute] has failed.
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</description>
</method>
<method name= "parse" >
<return type= "int" enum= "Error" >
</return>
<argument index= "0" name= "expression" type= "String" >
</argument>
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<argument index= "1" name= "input_names" type= "PackedStringArray" default= "PackedStringArray( )" >
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</argument>
<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>
</method>
</methods>
<constants >
</constants>
</class>