errant/tacit

<?php
namespace Tacit;
/**
 * Instruction Set
 *
 * @author Tom Morton
 */
class InstructionSet {

    protected $instructions = array();

    public function addInstruction($byteCode, \Tacit\Instruction $instruction)
    {
        if($byteCode < 10) {
            throw new \Exception('Unable overload reserved bytecode: ' . $byteCode);
        }

        $this->instructions[$byteCode] = $instruction;
    }

    public function getInstruction($byteCode)
    {
        if(!isset($this->instructions[$byteCode])) {
            throw new \Exception('Instruction Set Error: Unknown byte code: ' . $byteCode);
        }

        return $this->instructions[$byteCode];
    }

    public function addInstructions(array $instructions)
    {
        foreach($instructions as $bytecode => $instruction) {
            $this->addInstruction($bytecode, $instruction);
        }
    }

    public function getGrammar()
    {
        $grammar = array();
        foreach($this->instructions as $byte => $instruction) {
            $grammar[$instruction->command] = array($byte, $instruction);
        }
        return $grammar;
    }
}