Chris@13: <?php declare(strict_types=1);
Chris@13: 
Chris@13: namespace PhpParser\Internal;
Chris@13: 
Chris@13: /**
Chris@13:  * Provides operations on token streams, for use by pretty printer.
Chris@13:  *
Chris@13:  * @internal
Chris@13:  */
Chris@13: class TokenStream
Chris@13: {
Chris@13:     /** @var array Tokens (in token_get_all format) */
Chris@13:     private $tokens;
Chris@13:     /** @var int[] Map from position to indentation */
Chris@13:     private $indentMap;
Chris@13: 
Chris@13:     /**
Chris@13:      * Create token stream instance.
Chris@13:      *
Chris@13:      * @param array $tokens Tokens in token_get_all() format
Chris@13:      */
Chris@13:     public function __construct(array $tokens) {
Chris@13:         $this->tokens = $tokens;
Chris@13:         $this->indentMap = $this->calcIndentMap();
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Whether the given position is immediately surrounded by parenthesis.
Chris@13:      *
Chris@13:      * @param int $startPos Start position
Chris@13:      * @param int $endPos   End position
Chris@13:      *
Chris@13:      * @return bool
Chris@13:      */
Chris@13:     public function haveParens(int $startPos, int $endPos) : bool {
Chris@13:         return $this->haveTokenImmediativelyBefore($startPos, '(')
Chris@13:             && $this->haveTokenImmediatelyAfter($endPos, ')');
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Whether the given position is immediately surrounded by braces.
Chris@13:      *
Chris@13:      * @param int $startPos Start position
Chris@13:      * @param int $endPos   End position
Chris@13:      *
Chris@13:      * @return bool
Chris@13:      */
Chris@13:     public function haveBraces(int $startPos, int $endPos) : bool {
Chris@13:         return $this->haveTokenImmediativelyBefore($startPos, '{')
Chris@13:             && $this->haveTokenImmediatelyAfter($endPos, '}');
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Check whether the position is directly preceded by a certain token type.
Chris@13:      *
Chris@13:      * During this check whitespace and comments are skipped.
Chris@13:      *
Chris@13:      * @param int        $pos               Position before which the token should occur
Chris@13:      * @param int|string $expectedTokenType Token to check for
Chris@13:      *
Chris@13:      * @return bool Whether the expected token was found
Chris@13:      */
Chris@13:     public function haveTokenImmediativelyBefore(int $pos, $expectedTokenType) : bool {
Chris@13:         $tokens = $this->tokens;
Chris@13:         $pos--;
Chris@13:         for (; $pos >= 0; $pos--) {
Chris@13:             $tokenType = $tokens[$pos][0];
Chris@13:             if ($tokenType === $expectedTokenType) {
Chris@13:                 return true;
Chris@13:             }
Chris@13:             if ($tokenType !== \T_WHITESPACE
Chris@13:                 && $tokenType !== \T_COMMENT && $tokenType !== \T_DOC_COMMENT) {
Chris@13:                 break;
Chris@13:             }
Chris@13:         }
Chris@13:         return false;
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Check whether the position is directly followed by a certain token type.
Chris@13:      *
Chris@13:      * During this check whitespace and comments are skipped.
Chris@13:      *
Chris@13:      * @param int        $pos               Position after which the token should occur
Chris@13:      * @param int|string $expectedTokenType Token to check for
Chris@13:      *
Chris@13:      * @return bool Whether the expected token was found
Chris@13:      */
Chris@13:     public function haveTokenImmediatelyAfter(int $pos, $expectedTokenType) : bool {
Chris@13:         $tokens = $this->tokens;
Chris@13:         $pos++;
Chris@13:         for (; $pos < \count($tokens); $pos++) {
Chris@13:             $tokenType = $tokens[$pos][0];
Chris@13:             if ($tokenType === $expectedTokenType) {
Chris@13:                 return true;
Chris@13:             }
Chris@13:             if ($tokenType !== \T_WHITESPACE
Chris@13:                 && $tokenType !== \T_COMMENT && $tokenType !== \T_DOC_COMMENT) {
Chris@13:                 break;
Chris@13:             }
Chris@13:         }
Chris@13:         return false;
Chris@13:     }
Chris@13: 
Chris@13:     public function skipLeft(int $pos, $skipTokenType) {
Chris@13:         $tokens = $this->tokens;
Chris@13: 
Chris@13:         $pos = $this->skipLeftWhitespace($pos);
Chris@13:         if ($skipTokenType === \T_WHITESPACE) {
Chris@13:             return $pos;
Chris@13:         }
Chris@13: 
Chris@13:         if ($tokens[$pos][0] !== $skipTokenType) {
Chris@13:             // Shouldn't happen. The skip token MUST be there
Chris@13:             throw new \Exception('Encountered unexpected token');
Chris@13:         }
Chris@13:         $pos--;
Chris@13: 
Chris@13:         return $this->skipLeftWhitespace($pos);
Chris@13:     }
Chris@13: 
Chris@13:     public function skipRight(int $pos, $skipTokenType) {
Chris@13:         $tokens = $this->tokens;
Chris@13: 
Chris@13:         $pos = $this->skipRightWhitespace($pos);
Chris@13:         if ($skipTokenType === \T_WHITESPACE) {
Chris@13:             return $pos;
Chris@13:         }
Chris@13: 
Chris@13:         if ($tokens[$pos][0] !== $skipTokenType) {
Chris@13:             // Shouldn't happen. The skip token MUST be there
Chris@13:             throw new \Exception('Encountered unexpected token');
Chris@13:         }
Chris@13:         $pos++;
Chris@13: 
Chris@13:         return $this->skipRightWhitespace($pos);
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Return first non-whitespace token position smaller or equal to passed position.
Chris@13:      *
Chris@13:      * @param int $pos Token position
Chris@13:      * @return int Non-whitespace token position
Chris@13:      */
Chris@13:     public function skipLeftWhitespace(int $pos) {
Chris@13:         $tokens = $this->tokens;
Chris@13:         for (; $pos >= 0; $pos--) {
Chris@13:             $type = $tokens[$pos][0];
Chris@13:             if ($type !== \T_WHITESPACE && $type !== \T_COMMENT && $type !== \T_DOC_COMMENT) {
Chris@13:                 break;
Chris@13:             }
Chris@13:         }
Chris@13:         return $pos;
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Return first non-whitespace position greater or equal to passed position.
Chris@13:      *
Chris@13:      * @param int $pos Token position
Chris@13:      * @return int Non-whitespace token position
Chris@13:      */
Chris@13:     public function skipRightWhitespace(int $pos) {
Chris@13:         $tokens = $this->tokens;
Chris@13:         for ($count = \count($tokens); $pos < $count; $pos++) {
Chris@13:             $type = $tokens[$pos][0];
Chris@13:             if ($type !== \T_WHITESPACE && $type !== \T_COMMENT && $type !== \T_DOC_COMMENT) {
Chris@13:                 break;
Chris@13:             }
Chris@13:         }
Chris@13:         return $pos;
Chris@13:     }
Chris@13: 
Chris@13:     public function findRight($pos, $findTokenType) {
Chris@13:         $tokens = $this->tokens;
Chris@13:         for ($count = \count($tokens); $pos < $count; $pos++) {
Chris@13:             $type = $tokens[$pos][0];
Chris@13:             if ($type === $findTokenType) {
Chris@13:                 return $pos;
Chris@13:             }
Chris@13:         }
Chris@13:         return -1;
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Get indentation before token position.
Chris@13:      *
Chris@13:      * @param int $pos Token position
Chris@13:      *
Chris@13:      * @return int Indentation depth (in spaces)
Chris@13:      */
Chris@13:     public function getIndentationBefore(int $pos) : int {
Chris@13:         return $this->indentMap[$pos];
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Get the code corresponding to a token offset range, optionally adjusted for indentation.
Chris@13:      *
Chris@13:      * @param int $from   Token start position (inclusive)
Chris@13:      * @param int $to     Token end position (exclusive)
Chris@13:      * @param int $indent By how much the code should be indented (can be negative as well)
Chris@13:      *
Chris@13:      * @return string Code corresponding to token range, adjusted for indentation
Chris@13:      */
Chris@13:     public function getTokenCode(int $from, int $to, int $indent) : string {
Chris@13:         $tokens = $this->tokens;
Chris@13:         $result = '';
Chris@13:         for ($pos = $from; $pos < $to; $pos++) {
Chris@13:             $token = $tokens[$pos];
Chris@13:             if (\is_array($token)) {
Chris@13:                 $type = $token[0];
Chris@13:                 $content = $token[1];
Chris@13:                 if ($type === \T_CONSTANT_ENCAPSED_STRING || $type === \T_ENCAPSED_AND_WHITESPACE) {
Chris@13:                     $result .= $content;
Chris@13:                 } else {
Chris@13:                     // TODO Handle non-space indentation
Chris@13:                     if ($indent < 0) {
Chris@13:                         $result .= str_replace("\n" . str_repeat(" ", -$indent), "\n", $content);
Chris@13:                     } elseif ($indent > 0) {
Chris@13:                         $result .= str_replace("\n", "\n" . str_repeat(" ", $indent), $content);
Chris@13:                     } else {
Chris@13:                         $result .= $content;
Chris@13:                     }
Chris@13:                 }
Chris@13:             } else {
Chris@13:                 $result .= $token;
Chris@13:             }
Chris@13:         }
Chris@13:         return $result;
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Precalculate the indentation at every token position.
Chris@13:      *
Chris@13:      * @return int[] Token position to indentation map
Chris@13:      */
Chris@13:     private function calcIndentMap() {
Chris@13:         $indentMap = [];
Chris@13:         $indent = 0;
Chris@13:         foreach ($this->tokens as $token) {
Chris@13:             $indentMap[] = $indent;
Chris@13: 
Chris@13:             if ($token[0] === \T_WHITESPACE) {
Chris@13:                 $content = $token[1];
Chris@13:                 $newlinePos = \strrpos($content, "\n");
Chris@13:                 if (false !== $newlinePos) {
Chris@13:                     $indent = \strlen($content) - $newlinePos - 1;
Chris@13:                 }
Chris@13:             }
Chris@13:         }
Chris@13: 
Chris@13:         // Add a sentinel for one past end of the file
Chris@13:         $indentMap[] = $indent;
Chris@13: 
Chris@13:         return $indentMap;
Chris@13:     }
Chris@13: }