<?php
namespace eMacros\Environment;
use eMacros\Scope;
use eMacros\Package\Package;
use eMacros\Symbol;
class Environment extends Scope {
/**
* Imported packages
* @var array
*/
public $packages = array();
/**
* Program arguments
* @var array
*/
public $arguments = array();
/**
* Validates a aymbol
* @param \eMacros\Symbol $symbol
* @throws \UnexpectedValueException
* @return array
*/
protected static function symbol($symbol) {
if ($symbol instanceof Symbol) {
return array($symbol->symbol, $symbol->package);
}
throw new \UnexpectedValueException(sprintf("Unexpected value of type '%s'.", is_object($symbol) ? get_class($symbol) : gettype($symbol)));
}
/**
* Imports a package to current symbol table
* @param Package $package
* @param string $id
*/
public function import(Package $package, $id = null) {
$id = is_null($id) ? $package->id : $id;
//load symbols
$this->symbols = array_merge($package->symbols, $this->symbols);
//load macros
$this->macros = array_merge($package->macros, $this->macros);
//store package
$this->packages[$id] = $package;
}
/**
* Determines if a given package has been imported
* @param string $packageId
* @return boolean
*/
public function hasPackage($packageId) {
return in_array($packageId, array_keys($this->packages));
}
/**
* Obtains a symbol from environment table
* (non-PHPdoc)
* @see \eMacros\Scope::offsetGet()
*/
public function offsetGet($symbol) {
list($sym, $pck) = self::symbol($symbol);
if (!is_null($pck)) {
//check package
if (!array_key_exists($pck, $this->packages)) {
throw new \UnexpectedValueException(sprintf("Package '%s' not found.", $pck));
}
return $this->packages[$pck]->offsetGet($sym);
}
//is symbol defined on this scope?
if (array_key_exists($sym, $this->symbols)) {
return $this->symbols[$sym];
}
else {
foreach ($this->macros as $regex => $callback) {
if (preg_match($regex, $sym, $matches)) {
$this->symbols[$sym] = $callback->__invoke($matches);
return $this->symbols[$sym];
}
}
}
}
}
?>
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