CXLVI. Tokenizer Functions

简介

The tokenizer functions provide an interface to the PHP tokenizer embedded in the Zend Engine. Using these functions you may write your own PHP source analyzing or modification tools without having to deal with the language specification at the lexical level.

See also the appendix about tokens.

需求

要编译本扩展模块不需要外部库文件。

安装

Beginning with PHP 4.3.0 these functions are enabled by default. For older versions you have to configure and compile PHP with --enable-tokenizer. You can disable tokenizer support with --disable-tokenizer.

PHP 的 Windows 版本已经内置该扩展模块的支持。无需加载任何附加扩展库即可使用这些函数。

注: Builtin support for tokenizer is available with PHP 4.3.0.

预定义常量

以下常量由本扩展模块定义,因此只有在本扩展模块被编译到 PHP 中,或者在运行时被动态加载后才有效。

T_INCLUDE (integer)

T_INCLUDE_ONCE (integer)

T_EVAL (integer)

T_REQUIRE (integer)

T_REQUIRE_ONCE (integer)

T_LOGICAL_OR (integer)

T_LOGICAL_XOR (integer)

T_LOGICAL_AND (integer)

T_PRINT (integer)

T_PLUS_EQUAL (integer)

T_MINUS_EQUAL (integer)

T_MUL_EQUAL (integer)

T_DIV_EQUAL (integer)

T_CONCAT_EQUAL (integer)

T_MOD_EQUAL (integer)

T_AND_EQUAL (integer)

T_OR_EQUAL (integer)

T_XOR_EQUAL (integer)

T_SL_EQUAL (integer)

T_SR_EQUAL (integer)

T_BOOLEAN_OR (integer)

T_BOOLEAN_AND (integer)

T_IS_EQUAL (integer)

T_IS_NOT_EQUAL (integer)

T_IS_IDENTICAL (integer)

T_IS_NOT_IDENTICAL (integer)

T_IS_SMALLER_OR_EQUAL (integer)

T_IS_GREATER_OR_EQUAL (integer)

T_SL (integer)

T_SR (integer)

T_INC (integer)

T_DEC (integer)

T_INT_CAST (integer)

T_DOUBLE_CAST (integer)

T_STRING_CAST (integer)

T_ARRAY_CAST (integer)

T_OBJECT_CAST (integer)

T_BOOL_CAST (integer)

T_UNSET_CAST (integer)

T_NEW (integer)

T_EXIT (integer)

T_IF (integer)

T_ELSEIF (integer)

T_ELSE (integer)

T_ENDIF (integer)

T_LNUMBER (integer)

T_DNUMBER (integer)

T_STRING (integer)

T_STRING_VARNAME (integer)

T_VARIABLE (integer)

T_NUM_STRING (integer)

T_INLINE_HTML (integer)

T_CHARACTER (integer)

T_BAD_CHARACTER (integer)

T_ENCAPSED_AND_WHITESPACE (integer)

T_CONSTANT_ENCAPSED_STRING (integer)

T_ECHO (integer)

T_DO (integer)

T_WHILE (integer)

T_ENDWHILE (integer)

T_FOR (integer)

T_ENDFOR (integer)

T_FOREACH (integer)

T_ENDFOREACH (integer)

T_DECLARE (integer)

T_ENDDECLARE (integer)

T_AS (integer)

T_SWITCH (integer)

T_ENDSWITCH (integer)

T_CASE (integer)

T_DEFAULT (integer)

T_BREAK (integer)

T_CONTINUE (integer)

T_OLD_FUNCTION (integer)

T_OLD_FUNCTION is not defined in PHP 5.

T_FUNCTION (integer)

T_CONST (integer)

T_RETURN (integer)

T_USE (integer)

T_GLOBAL (integer)

T_STATIC (integer)

T_VAR (integer)

T_UNSET (integer)

T_ISSET (integer)

T_EMPTY (integer)

T_CLASS (integer)

T_EXTENDS (integer)

T_OBJECT_OPERATOR (integer)

T_DOUBLE_ARROW (integer)

T_LIST (integer)

T_ARRAY (integer)

T_LINE (integer)

T_FILE (integer)

T_COMMENT (integer)

T_ML_COMMENT (integer)

T_ML_COMMENT is not defined in PHP 5. All comments in PHP 5 are of token T_COMMENT.

T_DOC_COMMENT (integer)

T_DOC_COMMENT was introduced in PHP 5.

T_OPEN_TAG (integer)

T_OPEN_TAG_WITH_ECHO (integer)

T_CLOSE_TAG (integer)

T_WHITESPACE (integer)

T_START_HEREDOC (integer)

T_END_HEREDOC (integer)

T_DOLLAR_OPEN_CURLY_BRACES (integer)

T_CURLY_OPEN (integer)

T_PAAMAYIM_NEKUDOTAYIM (integer)

T_DOUBLE_COLON (integer)

T_INTERFACE (integer)

PHP 5 only.

T_IMPLEMENTS (integer)

PHP 5 only.

T_CLASS_C (integer)

PHP 5 only.

T_FUNC_C (integer)

PHP 5 only.

T_METHOD_C (integer)

PHP 5 only.

T_ABSTRACT (integer)

PHP 5 only.

T_CATCH (integer)

PHP 5 only.

T_FINAL (integer)

PHP 5 only.

T_INSTANCEOF (integer)

PHP 5 only.

T_PRIVATE (integer)

PHP 5 only.

T_PROTECTED (integer)

PHP 5 only.

T_PUBLIC (integer)

PHP 5 only.

T_THROW (integer)

PHP 5 only.

T_TRY (integer)

PHP 5 only.

T_CLONE (integer)

PHP 5 only.

范例

Here is a simple example PHP scripts using the tokenizer that will read in a PHP file, strip all comments from the source and print the pure code only.

例子 1. Strip comments with the tokenizer

<?php
/*
* T_ML_COMMENT does not exist in PHP 5.
* The following three lines define it in order to
* preserve backwards compatibility.
*
* The next two lines define the PHP 5 only T_DOC_COMMENT,
* which we will mask as T_ML_COMMENT for PHP 4.
*/
if (!defined('T_ML_COMMENT')) {
    
define('T_ML_COMMENT', T_COMMENT);
} else {
    
define('T_DOC_COMMENT', T_ML_COMMENT);
}

$source = file_get_contents('example.php');
$tokens = token_get_all($source);

foreach (
$tokens as $token) {
    if (
is_string($token)) {
        
// simple 1-character token
        
echo $token;
    } else {
        
// token array
        
list($id, $text) = $token;

        switch (
$id) {
            case
T_COMMENT:
            case
T_ML_COMMENT: // we've defined this
            
case T_DOC_COMMENT: // and this
                // no action on comments
                
break;

            default:
                
// anything else -> output "as is"
                
echo $text;
                break;
        }
    }
}
?>
目录
token_get_all -- Split given source into PHP tokens
token_name -- Get the symbolic name of a given PHP token

add a note add a note User Contributed Notes
lists at 5etdemi dot com
23-Jul-2005 04:33
The tokenizer functions are quite powerful. For example, you can retrieve all of the methods in a given class using an algorithm like:

for each token:
if token is T_FUNCTION then start buffer
if buffer is started then add the current string to the buffer
if token is ( stop buffer

And the great thing is that the class methods will have the right case, so it's a good way to get around the limitations with get_class_methods returning lowercase method names. Also since using a similar algorithm you can read the arguments of a function you can implement Reflections-like functionality into PHP4.

Finally you can use it as a simpler method of extracting Javadoc out of a class file to generate documentation. The util/MethodTable.php class in AMFPHP (http://www.amfphp.org) uses the tokenizer functions to create a method table with all of the arguments, a description, return type, etc. and from that method table it can generate ActionScript that matches the PHP, but it could also be fitted to generate JavaScript, documentation files, or basically anything you put your mind to. I can also see that this could be the base for a class -> WSDL file generator.