Issue 11279: Whitespace handling rules unclear                                                                                                                                                                       (mtt-ftf)
Source: TCS (Mr. Sreedhar Reddy, sreedhar.reddy@tcs.com)
Nature: Uncategorized Issue
Severity: 
Summary: Whitespace handling rules are not clear: 
1. Is whitespace preceding multi-line block expressions (such as for, if, etc) included in  the text output? Examples 
given in the appendix do not seem to include it. 
2. Whitespace handling rule 3 says: "Indentation of the text produced for the invoked template starts at the indentation at the point of the template invocation." Should this be the case even for an embedded template invocation, i.e. a template 
invocation that is surrounded by other expressions on the same line? 
E.g. 
[template printClass(c:Class)] 
class [c.name/] implements [printInterfaceName(c.implementsInterface) sep(',')] 
[/template] 
[template printInterfaceName(i:Interface)] 
[i.name/] 
[/template] 
Here printInterface is invoked iteratively for each interface implemented by the class. 
One would expect following kind of output from this: 
class myClass implements myIntf1, myIntf2, myIntf3,... 

But the rule seems to say that the output of each template invocation starts at the same indentation level. 
This is probably not the intended behaviour, atleast for embedded template invocations (like the one above). 

Resolution: Replace existing text in the section discussing whitespace handling with the text given
below,
Text production rules will be easier to specify by viewing the body of a template (or a
block expression) as follows:
<block-body> ::= <body-element>*
<body-element> ::= <literalString> | <whitespace> | <expression> | <BOL-indicator>
<whitespace> ::= space | tab | newline
<expression> ::= <stand-alone-block-expression> | <embedded-block-expression> |
<stand-alone-template-invocation> | <embedded-template-invocation> |
<other-expression>
<BOL-indicator> ::= ‘^’
<stand-alone-block-expression> is a block expression (single or multi-line) that is not
surrounded by other body elements on the lines where the block head and the tail occur.
<embedded-block-expression> is a block expression that is surrounded by other nonwhitespace
body elements on the lines where block head or tail occur.
<stand-alone-template-invocation> is a template invocation expression that stands on a
line all by itself.
<embedded-template-invocation> is a template invocation that is surrounded by other
body elements on the same line.
<other-expression> refers to all expressions other than the block and template invocation
expressions.
Text production rules:
- All body elements produce text
- The text output of a block-body is the sequential concatenation of the text outputs of
its body elements
- Rules for identifying starting and ending of block body:
o template: body starts at the beginning of the next line after the template head,
and ends on the last character (excluding the new line) of the line previous to
the template tail.
o multi-line-block: body starts at the beginning of the next line after the block
head, and ends on the last character (excluding the new line) of the line
previous to the block tail.
o single-line-block: body starts after the closing bracket of the block head and
ends before the starting bracket of the block tail.
- Text outputs of different body elements:
o A literal string is output as is.
o A whitespace character is output as is. The text produced by the execution of <other-expression> is output as is.
o The text produced by the execution of <embedded-block-expression> is
output as is.
o The text produced by the execution of <embedded-template-invocation> is
output as is.
o <stand-alone-block-expression> needs special handling:
.. Ignore the whitespace characters occurring before the beginning of the
head.
.. In the case of a multi-line 'for block', when a separator character is not
specified, use 'new line' as the default separator between the outputs
produced by successive iterations.
o <stand-alone-template-invocation> needs special handling:
.. Add the whitespace preceding the invocation expression before each
line of the text produced by the invoked template.
.. In the case of an iterative template invocation (e.g. when the argument
is a collection), if a separator character is not specified, use 'new line'
as the default separator between the outputs produced by successive
iterations.
<BOL-indicator> is a special character (‘^’) that marks the beginning of a line – i.e. on
the line on which this character appears, the whitespace preceding the character should be
excluded from the text output.
In code-explicit mode, all whitespace must be explicitly specified.
Move this section after the section describing concrete syntax.
Revised Text: 
Actions taken:
August 13, 2007: received issue
January 15, 2008: closed issue
Discussion: 

End of Annotations:=====
ronPort-AV: E=Sophos;i="4.19,254,1183314600"; 
   d="scan'208";a="108407831"
To: mtt-ftf@omg.org
Cc: juergen@omg.org
Subject: Whitespace handling rules unclear 
X-Mailer: Lotus Notes Release 6.5.4 March 27, 2005
From: Sreedhar Reddy <sreedhar.reddy@tcs.com>
Date: Mon, 13 Aug 2007 16:36:48 +0530
X-MIMETrack: Serialize by Router on InMumM01/TCS(Release 6.5.5FP2HF415 | June 20, 2007) at
 08/13/2007 16:36:49,
        Serialize complete at 08/13/2007 16:36:49



Whitespace handling rules are not clear: 
1. Is whitespace preceding multi-line block expressions (such as for, if, etc) included in  the text output? Examples 
given in the appendix do not seem to include it. 
2. Whitespace handling rule 3 says: "Indentation of the text produced for the invoked template starts at the indentation at the point of the template invocation." Should this be the case even for an embedded template invocation, i.e. a template 
invocation that is surrounded by other expressions on the same line? 
E.g. 
[template printClass(c:Class)] 
class [c.name/] implements [printInterfaceName(c.implementsInterface) sep(',')] 
[/template] 
[template printInterfaceName(i:Interface)] 
[i.name/] 
[/template] 
Here printInterface is invoked iteratively for each interface implemented by the class. 
One would expect following kind of output from this: 
class myClass implements myIntf1, myIntf2, myIntf3,... 

But the rule seems to say that the output of each template invocation starts at the same indentation level. 
This is probably not the intended behaviour, atleast for embedded template invocations (like the one above). 

Sreedhar 

Sreedhar S Reddy
Tata Consultancy Services
Mailto: sreedhar.reddy@tcs.com
Website: http://www.tcs.com
____________________________________________
Experience certainty.        IT Services
                       Business Solutions
                       Outsourcing
____________________________________________
=====-----=====-----=====
Notice: The information contained in this e-mail
message and/or attachments to it may contain 
confidential or privileged information. If you are 
not the intended recipient, any dissemination, use, 
review, distribution, printing or copying of the 
information contained in this e-mail message 
and/or attachments to it are strictly prohibited. If 
you have received this communication in error, 
please notify us by reply e-mail or telephone and 
immediately and permanently delete the message 
and any attachments. Thank you