1: <?php
 2: namespace Pharborist;
 3: 
 4: /**
 5:  * Iterator over tokens that supports peek.
 6:  */
 7: class TokenIterator {
 8:   /**
 9:    * The token array.
10:    * @var array
11:    */
12:   private $tokens;
13: 
14:   /**
15:    * Current position in array.
16:    * @var int
17:    */
18:   private $position;
19: 
20:   /**
21:    * The length of token array.
22:    * @var int
23:    */
24:   private $length;
25: 
26:   /**
27:    * @param TokenNode[] $tokens
28:    */
29:   public function __construct(array $tokens) {
30:     $this->tokens = $tokens;
31:     $this->length = count($tokens);
32:     $this->position = 0;
33:   }
34: 
35:   /**
36:    * Return the current token.
37:    * @return TokenNode
38:    */
39:   public function current() {
40:     if ($this->position >= $this->length) {
41:       return NULL;
42:     }
43:     return $this->tokens[$this->position];
44:   }
45: 
46:   /**
47:    * Peek ahead.
48:    * @param int $offset Offset from current position.
49:    * @return TokenNode
50:    */
51:   public function peek($offset) {
52:     if ($this->position + $offset >= $this->length) {
53:       return NULL;
54:     }
55:     return $this->tokens[$this->position + $offset];
56:   }
57: 
58:   /**
59:    * Move to the next token and return it.
60:    * @return TokenNode
61:    */
62:   public function next() {
63:     $this->position++;
64:     if ($this->position >= $this->length) {
65:       $this->position = $this->length;
66:       return NULL;
67:     }
68:     return $this->tokens[$this->position];
69:   }
70: 
71:   /**
72:    * Return TRUE if there are more tokens.
73:    * @return bool
74:    */
75:   public function hasNext() {
76:     return $this->position < $this->length;
77:   }
78: 
79:   /**
80:    * Return the source position.
81:    * @return SourcePosition
82:    */
83:   public function getSourcePosition() {
84:     if ($this->length === 0) {
85:       return new SourcePosition(1, 1);
86:     }
87:     $token = $this->current();
88:     if ($token === NULL) {
89:       $token = $this->tokens[$this->length - 1];
90:       $source_position = $token->getSourcePosition();
91:       $line_no = $source_position->getLineNumber();
92:       $col_no = $source_position->getColumnNumber();
93:       $length = strlen($token->getText());
94:       return new SourcePosition($line_no, $col_no + $length);
95:     }
96:     return $token->getSourcePosition();
97:   }
98: }
99: