Zephir\Variable::setPossibleValue PHP Method

    public function setPossibleValue(CompiledExpression $possibleValue, CompilationContext $compilationContext)
    {
        $this->possibleValue = $possibleValue;
        $this->possibleValueBranch = $compilationContext->branchManager->getCurrentBranch();
    }

 /**
  * Compiles foo = {expr}
  * Changes the value of a mutable variable
  *
  * @param string $variable
  * @param ZephirVariable $symbolVariable
  * @param CompiledExpression $resolvedExpr
  * @param ReadDetector $readDetector
  * @param CompilationContext $compilationContext
  * @param array $statement
  * @throws CompilerException
  */
 public function assign($variable, ZephirVariable $symbolVariable, CompiledExpression $resolvedExpr, ReadDetector $readDetector, CompilationContext $compilationContext, array $statement)
 {
     if ($symbolVariable->isReadOnly()) {
         throw new CompilerException("Cannot mutate variable '" . $variable . "' because it is read only", $statement);
     }
     $codePrinter = $compilationContext->codePrinter;
     /**
      * Only initialize variables if it's direct assignment
      */
     if ($statement['operator'] == 'assign') {
         $symbolVariable->setIsInitialized(true, $compilationContext, $statement);
     } else {
         if (!$symbolVariable->isInitialized()) {
             throw new CompilerException("Cannot mutate variable '" . $variable . "' because it is not initialized", $statement);
         }
     }
     /**
      * Set the assigned value to the variable as a CompiledExpression
      * We could use this expression for further analysis
      */
     $symbolVariable->setPossibleValue($resolvedExpr, $compilationContext);
     $type = $symbolVariable->getType();
     switch ($type) {
         case 'int':
         case 'uint':
         case 'long':
         case 'ulong':
         case 'char':
         case 'uchar':
             $this->doNumericAssignment($codePrinter, $resolvedExpr, $symbolVariable, $variable, $statement, $compilationContext);
             break;
         case 'double':
             $this->doDoubleAssignment($codePrinter, $resolvedExpr, $symbolVariable, $variable, $statement, $compilationContext);
             break;
         case 'array':
             $this->doArrayAssignment($codePrinter, $resolvedExpr, $symbolVariable, $variable, $statement, $compilationContext);
             break;
         case 'string':
             $this->doStringAssignment($codePrinter, $resolvedExpr, $symbolVariable, $variable, $statement, $compilationContext);
             break;
         case 'bool':
             $this->doBoolAssignment($codePrinter, $resolvedExpr, $symbolVariable, $variable, $statement, $compilationContext);
             break;
         case 'variable':
             $this->doVariableAssignment($codePrinter, $resolvedExpr, $symbolVariable, $variable, $statement, $compilationContext, $readDetector);
             break;
         default:
             throw new CompilerException("Unknown type: " . $type, $statement);
     }
 }