Class PhpParser\ConstExprEvaluator

Evaluates constant expressions.

This evaluator is able to evaluate all constant expressions (as defined by PHP), which can be evaluated without further context. If a subexpression is not of this type, a user-provided fallback evaluator is invoked. To support all constant expressions that are also supported by PHP (and not already handled by this class), the fallback evaluator must be able to handle the following node types:

All Scalar\MagicConst* nodes.
Expr\ConstFetch nodes. Only null/false/true are already handled by this class.
Expr\ClassConstFetch nodes.

The fallback evaluator should throw ConstExprEvaluationException for nodes it cannot evaluate.

The evaluation is dependent on runtime configuration in two respects: Firstly, floating point to string conversions are affected by the precision ini setting. Secondly, they are also affected by the LC_NUMERIC locale.

Located at vendor/nikic/php-parser/lib/PhpParser/ConstExprEvaluator.php

Methods


					
	public

__construct(callable|null $fallbackEvaluator = null)

Create a constant expression evaluator.

The provided fallback evaluator is invoked whenever a subexpression cannot be evaluated. See class doc comment for more information.

Parameters

$fallbackEvaluator

To call if subexpression cannot be evaluated


					
	public

evaluateSilently(Expr $expr): mixed

Silently evaluates a constant expression into a PHP value.

Thrown Errors, warnings or notices will be converted into a ConstExprEvaluationException. The original source of the exception is available through getPrevious().

If some part of the expression cannot be evaluated, the fallback evaluator passed to the constructor will be invoked. By default, if no fallback is provided, an exception of type ConstExprEvaluationException is thrown.

See class doc comment for caveats and limitations.

Parameters

$expr

Constant expression to evaluate

Returns

Result of evaluation

Throws

PhpParser\ConstExprEvaluationException

if the expression cannot be evaluated or an error occurred


					
	public

evaluateDirectly(Expr $expr): mixed

Directly evaluates a constant expression into a PHP value.

May generate Error exceptions, warnings or notices. Use evaluateSilently() to convert these into a ConstExprEvaluationException.

See class doc comment for caveats and limitations.

Parameters

$expr

Constant expression to evaluate

Returns

Result of evaluation

Throws

PhpParser\ConstExprEvaluationException

if the expression cannot be evaluated

Namespaces

Classes

Interfaces

Exceptions

Class PhpParser\ConstExprEvaluator

Parameters

Parameters

Returns

Throws

Parameters

Returns

Throws