<?php
namespace eMacros;
class Scope implements \ArrayAccess, \IteratorAggregate {
/**
* Symboil table
* @var array
*/
public $symbols = array();
/**
* Macros list
* @var array
*/
public $macros = array();
protected static function symbol($symbol) {
if ($symbol instanceof Symbol) {
return $symbol->symbol;
}
elseif (is_string($symbol)) {
return $symbol;
}
throw new \UnexpectedValueException(sprintf("Unexpected value of type '%s'.", is_object($symbol) ? get_class($symbol) : gettype($symbol)));
}
/**
* Obtains a symbol from table
* (non-PHPdoc)
* @see ArrayAccess::offsetGet()
*/
public function offsetGet($symbol) {
$sym = self::symbol($symbol);
//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];
}
}
}
return null;
}
public function offsetExists($symbol) {
return true;
}
/**
* Stores a symbol
* Used when setting up a Scope/Package
* Ex: $this['.'] = new Concatenation();
* (non-PHPdoc)
* @see ArrayAccess::offsetSet()
*/
public function offsetSet($symbol, $value) {
$symbol = Symbol::validateSymbol($symbol);
$this->symbols[$symbol] = $value;
}
/**
* Removes a symbol from table
* (non-PHPdoc)
* @see ArrayAccess::offsetUnset()
*/
public function offsetUnset($symbol) {
unset($this->symbols[$symbol]);
}
/**
* Obtains a symbol iterator
* (non-PHPdoc)
* @see IteratorAggregate::getIterator()
*/
public function getIterator() {
$symbols = array();
foreach ($this->listSymbols() as $name) {
$symbols[$name] = $this[$name];
}
return new \ArrayIterator($symbols);
}
/**
* Obtains all defined symbols
* @return array
*/
public function listSymbols() {
return array_keys($this->symbols);
}
/**
* Adds a new macro
* @param string $regex
* @param \Closure $handler
*/
public function macro($regex, \Closure $handler) {
$this->macros[$regex] = $handler;
}
}
?>
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