blob: 222c17f96b1093b982d8887352a64e7fa2d6285d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
<?php
/*
* Context.php - template parser symbol table
*
* Copyright (c) 2013 Elmar Ludwig
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*/
namespace exTpl;
/**
* A Context object represents the symbol table used to resolve
* symbol names to their values in the local scope. Each context
* may inherit symbol definitions from its parent context.
*/
class Context
{
private $bindings;
private $parent;
/**
* Initializes a new Context instance with the given bindings.
*
* @param array $bindings symbol table
* @param Context $parent parent context (or NULL)
*/
public function __construct($bindings, Context $parent = NULL)
{
$this->bindings = $bindings;
$this->parent = $parent;
}
/**
* Looks up the value of a symbol in this context and returns it.
* The reserved symbol "this" is an alias for the current context.
*
* @param string $key symbol name
*/
public function lookup($key)
{
if (isset($this->bindings[$key])) {
return $this->bindings[$key];
} else if ($this->parent) {
return $this->parent->lookup($key);
}
return NULL;
}
}
|
