Escape handling Mk II (new code committed)

["Geir Magnusson Jr." <ge...@optonline.net>]

Symmetry be damned, indeed.

The code for escape handling v2 is now in.  Thanks to all for the
comments and discussion.  I hope that this will be satisfactory to
everyone.  If not, I am sure that y'all will speak up.

To review, the point of this is to make Velocity / VTL as non-invasive
to the schmoo, the non-VTL content in the template.

Simply put :

1) The '\' character acts as a conventional bind-from-the-left escape
character if and only if it appears on the left side of a VTL reference
or directive.

2) In all other cases, it is just a '\'

VTL reference := a syntax element $<name> such that a <name>,Object pair
is found in the Context.

VTL directive := a control directive or a pluggable directive, currently
including #set, #if, #else, #elsif, #end, #foreach, #include, #parse,
#macro and #stop. 


Examples :

With $foo in the Context, it is 'active':

$foo renders as <foo>
\$foo renders as \$foo
\\$foo renders as \<foo>  (because it binds from the left)
\\\$foo renders as \\$foo

With $foo NOT in the context, it's just text:

$foo renders as $foo
\$foo renders as  \$foo
\\$foo renders as \\$foo 

Directives :

#include("a.txt") renders as <contents of a.txt>
\#include("a.txt") renders as \#include("a.txt")
\\#include("a.txt") renders as \<contents of a.txt>
etc

\#if(true) hi \#end  renders as #if(true) hi #end
\\#if(true) hi \\#end renders as \ hi \
\\\#if(true) hi \\#end is a parsing error after 'hi' :) (because the #if
is escaped, so there is a #end just sitting there )

Take a look at test/templates/escape2.vm for more good examples.

geir

-- 
Geir Magnusson Jr.                               geirm@optonline.com
Dakota tribal wisdom: "when you discover you are riding a dead horse,
the best strategy is to dismount."