Introduce Stmt\Block

Stmt\Block will be created for { $a; } style blocks, unless these
occur directly inside some structure that is usually combined
with a block.

For example if ($a) { $b; } will continue to use the old
representation (plain array in in If_::$stmts), but a free-standing
{ $b; } will become a Stmt\Block.

Fixes #590.

grammar/php.y

@@ -366,21 +366,13 @@ inner_statement:
 ;
 
 non_empty_statement:
-      '{' inner_statement_list '}'
-    {
-        if ($2) {
-            $$ = $2; prependLeadingComments($$);
-        } else {
-            makeNop($$);
-            if (null === $$) { $$ = array(); }
-        }
-    }
-    | T_IF '(' expr ')' statement elseif_list else_single
-          { $$ = Stmt\If_[$3, ['stmts' => toArray($5), 'elseifs' => $6, 'else' => $7]]; }
+      '{' inner_statement_list '}'                          { $$ = Stmt\Block[$2]; }
+    | T_IF '(' expr ')' blocklike_statement elseif_list else_single
+          { $$ = Stmt\If_[$3, ['stmts' => $5, 'elseifs' => $6, 'else' => $7]]; }
     | T_IF '(' expr ')' ':' inner_statement_list new_elseif_list new_else_single T_ENDIF ';'
           { $$ = Stmt\If_[$3, ['stmts' => $6, 'elseifs' => $7, 'else' => $8]]; }
     | T_WHILE '(' expr ')' while_statement                  { $$ = Stmt\While_[$3, $5]; }
-    | T_DO statement T_WHILE '(' expr ')' ';'               { $$ = Stmt\Do_   [$5, toArray($2)]; }
+    | T_DO blocklike_statement T_WHILE '(' expr ')' ';'     { $$ = Stmt\Do_   [$5, $2]; }
     | T_FOR '(' for_expr ';'  for_expr ';' for_expr ')' for_statement
           { $$ = Stmt\For_[['init' => $3, 'cond' => $5, 'loop' => $7, 'stmts' => $9]]; }
     | T_SWITCH '(' expr ')' switch_case_list                { $$ = Stmt\Switch_[$3, $5]; }
@@ -416,14 +408,16 @@ non_empty_statement:
           { $$ = Stmt\TryCatch[$3, $5, $6]; $this->checkTryCatch($$); }
     | T_GOTO identifier_not_reserved semi                   { $$ = Stmt\Goto_[$2]; }
     | identifier_not_reserved ':'                           { $$ = Stmt\Label[$1]; }
-    | error                                                 { $$ = array(); /* means: no statement */ }
+    | error                                                 { $$ = null; /* means: no statement */ }
 ;
 
 statement:
       non_empty_statement
-    | ';'
-          { makeNop($$);
-            if ($$ === null) $$ = array(); /* means: no statement */ }
+    | ';'                                                   { makeNop($$); }
+;
+
+blocklike_statement:
+     statement                                              { toBlock($1); }
 ;
 
 catches:
@@ -554,17 +548,17 @@ non_empty_class_name_list:
 ;
 
 for_statement:
-      statement                                             { $$ = toArray($1); }
+      blocklike_statement
     | ':' inner_statement_list T_ENDFOR ';'                 { $$ = $2; }
 ;
 
 foreach_statement:
-      statement                                             { $$ = toArray($1); }
+      blocklike_statement
     | ':' inner_statement_list T_ENDFOREACH ';'             { $$ = $2; }
 ;
 
 declare_statement:
-      non_empty_statement                                   { $$ = toArray($1); }
+      non_empty_statement                                   { toBlock($1); }
     | ';'                                                   { $$ = null; }
     | ':' inner_statement_list T_ENDDECLARE ';'             { $$ = $2; }
 ;
@@ -624,7 +618,7 @@ match_arm:
 ;
 
 while_statement:
-      statement                                             { $$ = toArray($1); }
+      blocklike_statement                                   { $$ = $1; }
     | ':' inner_statement_list T_ENDWHILE ';'               { $$ = $2; }
 ;
 
@@ -634,7 +628,7 @@ elseif_list:
 ;
 
 elseif:
-      T_ELSEIF '(' expr ')' statement                       { $$ = Stmt\ElseIf_[$3, toArray($5)]; }
+      T_ELSEIF '(' expr ')' blocklike_statement             { $$ = Stmt\ElseIf_[$3, $5]; }
 ;
 
 new_elseif_list:
@@ -649,7 +643,7 @@ new_elseif:
 
 else_single:
       /* empty */                                           { $$ = null; }
-    | T_ELSE statement                                      { $$ = Stmt\Else_[toArray($2)]; }
+    | T_ELSE blocklike_statement                            { $$ = Stmt\Else_[$2]; }
 ;
 
 new_else_single:

grammar/phpyLang.php

@@ -87,14 +87,15 @@ function ($matches) {
             if ('pushNormalizing' === $name) {
                 assertArgs(2, $args, $name);
 
-                return 'if (is_array(' . $args[1] . ')) { $$ = array_merge(' . $args[0] . ', ' . $args[1] . '); }'
-                       . ' else { ' . $args[0] . '[] = ' . $args[1] . '; $$ = ' . $args[0] . '; }';
+                return 'if (' . $args[1] . ' !== null) { ' . $args[0] . '[] = ' . $args[1] . '; } $$ = ' . $args[0] . ';';
             }
 
-            if ('toArray' == $name) {
+            if ('toBlock' == $name) {
                 assertArgs(1, $args, $name);
 
-                return 'is_array(' . $args[0] . ') ? ' . $args[0] . ' : array(' . $args[0] . ')';
+                return 'if (' . $args[0] . ' instanceof Stmt\Block) { $$ = ' . $args[0] . '->stmts; } '
+                     . 'else if (' . $args[0] . ' === null) { $$ = []; } '
+                     . 'else { $$ = [' . $args[0] . ']; }';
             }
 
             if ('parseVar' === $name) {
@@ -122,15 +123,6 @@ function ($matches) {
                 return $args[0] . ' = $this->maybeCreateZeroLengthNop($this->tokenPos);';
             }
 
-            if ('prependLeadingComments' === $name) {
-                assertArgs(1, $args, $name);
-
-                return '$comments = $this->getCommentsBeforeToken($this->tokenStartStack[#1]); $stmts = ' . $args[0] . '; '
-                       . 'if (!empty($comments)) {'
-                       . '$stmts[0]->setAttribute(\'comments\', '
-                       . 'array_merge($comments, $stmts[0]->getAttribute(\'comments\', []))); }';
-            }
-
             return $matches[0];
         },
         $code

lib/PhpParser/Internal/TokenStream.php

@@ -195,12 +195,6 @@ public function haveTokenInRange(int $startPos, int $endPos, $tokenType): bool {
         return false;
     }
 
-    public function haveBracesInRange(int $startPos, int $endPos): bool {
-        return $this->haveTokenInRange($startPos, $endPos, '{')
-            || $this->haveTokenInRange($startPos, $endPos, T_CURLY_OPEN)
-            || $this->haveTokenInRange($startPos, $endPos, '}');
-    }
-
     public function haveTagInRange(int $startPos, int $endPos): bool {
         return $this->haveTokenInRange($startPos, $endPos, \T_OPEN_TAG)
             || $this->haveTokenInRange($startPos, $endPos, \T_CLOSE_TAG);

lib/PhpParser/Node/Stmt/Block.php

@@ -0,0 +1,29 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\Node\Stmt;
+
+use PhpParser\Node\Stmt;
+
+class Block extends Stmt {
+    /** @var Stmt[] Statements */
+    public array $stmts;
+
+    /**
+     * A block of statements.
+     *
+     * @param Stmt[] $stmts Statements
+     * @param array<string, mixed> $attributes Additional attributes
+     */
+    public function __construct(array $stmts, array $attributes = []) {
+        $this->attributes = $attributes;
+        $this->stmts = $stmts;
+    }
+
+    public function getType(): string {
+        return 'Stmt_Block';
+    }
+
+    public function getSubNodeNames(): array {
+        return ['stmts'];
+    }
+}