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--- rfc:flexible_heredoc_nowdoc_syntaxes [2017/09/16 16:26] – created tpunt
+++ rfc:flexible_heredoc_nowdoc_syntaxes [2017/09/27 10:43] – tpunt
@@ Line 39: / Line 39: @@
 // no indentation
 echo <<<END
-   a
+      a
-  b
+     b
- c
+    c
 END;
 /*
-   a
+      a
-  b
+     b
- c
+    c
 */
-// 1 space of indentation
+// 4 spaces of indentation
 echo <<<END
-   a
+      a
-  b
+     b
- c
+    c
- END;
+    END;
 /*
   a
  b
-c
-*/
-// 2 spaces of indentation
-echo <<<END
-   a
-  b
- c
-  END;
-/*
- a
-b
-c
-*/
-// 3 (or more) spaces of indentation
-echo <<<END
-   a
-  b
- c
-   END;
-/*
-a
-b
 c
 */
 </code>
-Tabs are supported as well. If tabs and spaces are intermixed (for whatever reason...), then each space and each tab is considered as 1 indentation. So if the closing marker is indented by 1 tab, and the heredoc/nowdoc body is indented by spaces, then regardless of the closing marked *looking* further indented, only 1 bit of whitespace will still be stripped from each line:
+If the closing marker is indented further than any lines of the body, then a ''ParseError'' will be thrown:
 <code php>
-// 1 tab indentation
 echo <<<END
-   a
-  b
- c
-	END;
-/*
   a
  b
 c
-*/
+ END;
+// Parse error: Invalid body indentation level (expecting an indentation at least 5) in %s on line %d
 </code>
-Moral of the story: don't mix tabs and spaces...
+Tabs are supported as well, however, tabs and spaces **must not** be intermixed regarding the indentation of the closing marker and the indentation of the body (up to the closing marker). In any of these cases, a ''ParseError'' will be thrown:
+<code php>
+// different indentation for body (spaces) ending marker (tabs)
+{
+	echo <<<END
+	 a
+		END;
+}
+// mixing spaces and tabs in body
+{
+    echo <<<END
+    	a
+     END;
+}
+// mixing spaces and tabs in ending marker
+{
+	echo <<<END
+		 a
+		 END;
+}
+</code>
+These whitespace constraints have been included because mixing tabs and spaces for indentation is harmful to legibility.
 ==== Closing Marker New Line ====
+Currently, in order to terminate a heredoc or nowdoc, a new line **must** be used after the closing marker (with the option
 Removing the closing marker requirement will change code from:
 <code php>
@@ Line 151: / Line 149: @@
 The implementation I am proposing avoids this problem by checking to see if a continuation of the found marker exists, and if so, then if it forms a valid identifier. This means that the terminating marker string will only be considered as such if it is matched exactly as a standalone, valid symbol (that is also found at the start of the line). This enables for the above snippet to now work.
-Something such as the following will still not work, however:
+Examples such as the following will still not work, however:
 <code php>
 $values = [<<<END
@@ Line 160: / Line 158: @@
 /*
 Parse error: syntax error, unexpected 'ING' (T_STRING), expecting ']' in %s on line %d
+*/
+echo <<<END
+END{$var}
+END;
+/*
+Parse error: syntax error, unexpected '$var' (T_VARIABLE) in %s on line %d
 */
 </code>
-(Notice the space after the first ''END''.) There is not a great deal that can be done about this. So the simple rule is: **do not choose a marker that appears in the body of the text** (though it would specifically have to occur at the start of a line in the text to cause problems).
+There is not a great deal that can be done about this. So the simple rule is: **do not choose a marker that appears in the body of the text** (though it would specifically have to occur at the start of a line in the text to cause problems).
 ===== Backward Incompatible Changes =====
@@ Line 181: / Line 186: @@
 {
     stringManipulator(<<<END
-       a
+   a
-      b
+  b
-     c
+ c
 END
 );

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