Add pipe operator support

Author: rlerdorf

TOLERANT_TODO.md

@@ -75,7 +75,7 @@ Recommended sample inputs for AST diffs (update as new fixtures are added):
 | Dynamic class const fetch | `tests/samples/dynamic_class_const.php` | 8.3 | `php ~/phan/tools/dump_ast.php --json …` | `php tools/PrintTolerantAst.php …` + `php ~/phan/internal/dump_fallback_ast.php --php-ast …` |
 | Property hooks | `tests/samples/property_hooks.php` | 8.4 | (run after `sudo newphp 84`) | same as above |
 | Asymmetric visibility props | (add fixture) | 8.4 | … | … |
-| Pipe operator | (add fixture once implemented) | 8.5 | … | … |
+| Pipe operator | `tests/samples/pipe_operator.php` | 8.5 | `php ~/phan/tools/dump_ast.php --json …` | `php tools/PrintTolerantAst.php …`, `php ~/phan/internal/dump_fallback_ast.php --php-ast …` |
 | `clone with` expressions | (add fixture) | 8.5 | … | … |
 
 ## Next Steps

src/Parser.php

@@ -2303,11 +2303,14 @@ private function parseBinaryExpressionOrHigher($precedence, $parentNode) {
             TokenKind::QuestionToken => [10, Associativity::Left],
 //            TokenKind::ColonToken => [9, Associativity::Left],
 
-            // TODO coalesce-expression (R)
-            TokenKind::QuestionQuestionToken => [9, Associativity::Right],
+        // TODO coalesce-expression (R)
+        TokenKind::QuestionQuestionToken => [9, Associativity::Right],
 
-            //logical-inc-OR-expression-1 (L)
-            TokenKind::BarBarToken => [12, Associativity::Left],
+        // pipe-expression (L)
+        TokenKind::PipeToken => [11, Associativity::Left],
+
+        //logical-inc-OR-expression-1 (L)
+        TokenKind::BarBarToken => [12, Associativity::Left],
 
             // logical-AND-expression-1 (L)
             TokenKind::AmpersandAmpersandToken => [13, Associativity::Left],

src/PhpTokenizer.php

@@ -14,6 +14,7 @@
 define(__NAMESPACE__ . '\T_MATCH', defined('T_MATCH') ? constant('T_MATCH') : 'T_MATCH');
 define(__NAMESPACE__ . '\T_NULLSAFE_OBJECT_OPERATOR', defined('T_NULLSAFE_OBJECT_OPERATOR') ? constant('T_NULLSAFE_OBJECT_OPERATOR') : 'T_NULLSAFE_OBJECT_OPERATOR');
 define(__NAMESPACE__ . '\T_ATTRIBUTE', defined('T_ATTRIBUTE') ? constant('T_ATTRIBUTE') : 'T_ATTRIBUTE');
+define(__NAMESPACE__ . '\T_PIPE', defined('T_PIPE') ? constant('T_PIPE') : 'T_PIPE');
 // If this predates PHP 8.1, T_ENUM is unavailable. The replacement value is arbitrary - it just has to be different from other values of token constants.
 define(__NAMESPACE__ . '\T_ENUM', defined('T_ENUM') ? constant('T_ENUM') : 'T_ENUM');
 define(__NAMESPACE__ . '\T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG', defined('T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG') ? constant('T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG') : 'T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG');
@@ -346,6 +347,7 @@ protected static function tokenGetAll(string $content, $parseContext): array
         T_AMPERSAND_FOLLOWED_BY_VAR_OR_VARARG => TokenKind::AmpersandToken,
         T_BOOLEAN_AND => TokenKind::AmpersandAmpersandToken,
         T_BOOLEAN_OR => TokenKind::BarBarToken,
+        T_PIPE => TokenKind::PipeToken,
         ":" => TokenKind::ColonToken,
         ";" => TokenKind::SemicolonToken,
         "=" => TokenKind::EqualsToken,

src/TokenKind.php

@@ -156,6 +156,7 @@ class TokenKind {
     const QuestionQuestionEqualsToken = 262;
     const QuestionArrowToken = 263;
     const AttributeToken = 264;
+    const PipeToken = 265;
 
     const DecimalLiteralToken = 301;
     const OctalLiteralToken = 302;

src/TokenStringMaps.php

@@ -169,6 +169,7 @@ class TokenStringMaps {
         "?->" => TokenKind::QuestionArrowToken,
         "??" => TokenKind::QuestionQuestionToken,
         "??=" => TokenKind::QuestionQuestionEqualsToken,
+        "|>" => TokenKind::PipeToken,
         "<=>" => TokenKind::LessThanEqualsGreaterThanToken,
         "<>" => TokenKind::LessThanGreaterThanToken,
         "..." => TokenKind::DotDotDotToken,

tests/samples/pipe_operator.php

@@ -0,0 +1,3 @@
+<?php
+
+$result = 1 |> fn($x) => $x + 1;