File: src/eMacros/Environment/Environment.php

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File: src/eMacros/Environment/Environment.php
Role: Class source
Content type: text/plain
Description: Class source
Class: eMacros
PHP LISP language interpreter
Author: By
Last change:
Date: 7 years ago
Size: 2,143 bytes
 

Contents

Class file image Download
<?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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