Merge pull request #181 from xp-framework/feature/pipelines

Add support for pipelines with `|>` and `?|>`

Author: thekid

composer.json

@@ -8,7 +8,7 @@
   "require" : {
     "xp-framework/core": "^12.0 | ^11.6 | ^10.16",
     "xp-framework/reflection": "^3.2 | ^2.15",
-    "xp-framework/ast": "^11.5",
+    "xp-framework/ast": "^11.6",
     "php" : ">=7.4.0"
   },
   "require-dev" : {

src/main/php/lang/ast/emit/EmulatePipelines.class.php

@@ -0,0 +1,49 @@
+<?php namespace lang\ast\emit;
+
+use lang\ast\nodes\{CallableExpression, CallableNewExpression, Variable};
+
+/**
+ * Emulates pipelines / the pipe operator, including a null-safe version.
+ *
+ * @see  https://wiki.php.net/rfc/pipe-operator-v3
+ * @see  https://externals.io/message/107661#107670
+ * @test lang.ast.unittest.emit.PipelinesTest
+ */
+trait EmulatePipelines {
+
+  protected function emitPipeTarget($result, $target, $arg) {
+    if ($target instanceof CallableNewExpression) {
+      $target->type->arguments= [new Variable(substr($arg, 1))];
+      $this->emitOne($result, $target->type);
+      $target->type->arguments= null;
+    } else if ($target instanceof CallableExpression) {
+      $this->emitOne($result, $target->expression);
+      $result->out->write('('.$arg.')');
+    } else {
+      $result->out->write('(');
+      $this->emitOne($result, $target);
+      $result->out->write(')('.$arg.')');
+    }
+  }
+
+  protected function emitPipe($result, $pipe) {
+
+    // $expr |> strtoupper(...) => [$arg= $expr, strtoupper($arg)][1]
+    $t= $result->temp();
+    $result->out->write('['.$t.'=');
+    $this->emitOne($result, $pipe->expression);
+    $result->out->write(',');
+    $this->emitPipeTarget($result, $pipe->target, $t);
+    $result->out->write('][1]');
+  }
+
+  protected function emitNullsafePipe($result, $pipe) {
+
+    // $expr ?|> strtoupper(...) => null === ($arg= $expr) ? null : strtoupper($arg)
+    $t= $result->temp();
+    $result->out->write('null===('.$t.'=');
+    $this->emitOne($result, $pipe->expression);
+    $result->out->write(')?null:');
+    $this->emitPipeTarget($result, $pipe->target, $t);
+  }
+}

src/main/php/lang/ast/emit/PHP.class.php

@@ -1156,6 +1156,22 @@ protected function emitNullsafeInstance($result, $instance) {
     $this->emitOne($result, $instance->member);
   }
 
+  protected function emitPipe($result, $pipe) {
+    $this->emitOne($result, $pipe->expression);
+    $result->out->write('|>');
+    $this->emitOne($result, $pipe->target);
+  }
+
+  protected function emitNullsafePipe($result, $pipe) {
+
+    // $expr ?|> strtoupper(...) => null === ($t= $expr) ? null : $t |> strtoupper(...)
+    $t= $result->temp();
+    $result->out->write('null===('.$t.'=');
+    $this->emitOne($result, $pipe->expression);
+    $result->out->write(')?null:'.$t.'|>');
+    $this->emitOne($result, $pipe->target);
+  }
+
   protected function emitUnpack($result, $unpack) {
     $result->out->write('...');
     $this->emitOne($result, $unpack->expression);

src/main/php/lang/ast/emit/PHP74.class.php

@@ -14,6 +14,7 @@ class PHP74 extends PHP {
     AttributesAsComments,
     CallablesAsClosures,
     ChainScopeOperators,
+    EmulatePipelines,
     MatchAsTernaries,
     NonCapturingCatchVariables,
     NullsafeAsTernaries,

src/main/php/lang/ast/emit/PHP80.class.php

@@ -21,6 +21,7 @@ class PHP80 extends PHP {
   use
     ArrayUnpackUsingMerge,
     CallablesAsClosures,
+    EmulatePipelines,
     OmitConstantTypes,
     ReadonlyClasses,
     RewriteBlockLambdaExpressions,

src/main/php/lang/ast/emit/PHP81.class.php

@@ -20,6 +20,7 @@
  */
 class PHP81 extends PHP {
   use
+    EmulatePipelines,
     RewriteBlockLambdaExpressions,
     RewriteDynamicClassConstants,
     RewriteStaticVariableInitializations,

src/main/php/lang/ast/emit/PHP82.class.php

@@ -20,6 +20,7 @@
  */
 class PHP82 extends PHP {
   use
+    EmulatePipelines,
     RewriteBlockLambdaExpressions,
     RewriteDynamicClassConstants,
     RewriteStaticVariableInitializations,

src/main/php/lang/ast/emit/PHP83.class.php

@@ -15,10 +15,11 @@
 /**
  * PHP 8.3 syntax
  *
+ * @test lang.ast.unittest.emit.PHP83Test
  * @see  https://wiki.php.net/rfc#php_83
  */
 class PHP83 extends PHP {
-  use RewriteBlockLambdaExpressions, RewriteProperties;
+  use EmulatePipelines, RewriteBlockLambdaExpressions, RewriteProperties;
 
   public $targetVersion= 80300;
 

src/main/php/lang/ast/emit/PHP84.class.php

@@ -15,10 +15,11 @@
 /**
  * PHP 8.4 syntax
  *
+ * @test lang.ast.unittest.emit.PHP84Test
  * @see  https://wiki.php.net/rfc#php_84
  */
 class PHP84 extends PHP {
-  use RewriteBlockLambdaExpressions;
+  use EmulatePipelines, RewriteBlockLambdaExpressions;
 
   public $targetVersion= 80400;