Re: Document projects header

[Lars H. <Lar...@re...>]

Joachim Kock skrev:
> On 06/07/09 14:17, Richard M. wrote:
>> In AlphaX 8.2b13, trying Electrics menu ->  Standard templates ->
>> createHeader
>> yields:
>>
>> [docProj::topHeader] error!
>> can't read "info(ctime)": no such variable
> 
> Hello Richard,
> 
> thanks for catching this.  I have looked into this, and it
> seems it involves some very strange bugs.  I don't expect
> you to have any interest in the remaining explanations,
> really addressed at the developers list.
> 
[snip]
> 
> In summary there are two strange bugs:
> 
> 1: file stat only works as expected if the variable is
>     fully qualified

This is because our [file] is a proc wrapper around the real thing. 
[info body file] returns:


		if {[lindex $args 0] eq "normalize"} {
			set result [::__file {*}$args]
			return [unicodeNormalize FormC $result]
		} else {
			return [::__file {*}$args]
		}
	
The calls to [__file] (Tcl core command) should really be [uplevel]ed, 
so that subcommands like [file stat] can access local variables from 
the calling context, rather than the context of the [file] proc. In 
other words, [file stat "/path/to/some/existing/file" AA] really filled 
in the AA array, although it was the AA array in [file]...

A nicer way to fix this could however be to turn [file] into a an 
ensemble, and do the patching at that level. (I wouldn't be surprised 
if [file] becomes an ensemble in Tcl 8.6.0 -- [info], [string], and 
[clock] already are -- but at least in 8.6b1 it's still a simple 
command.) In that case, the patching can be done as follows:

   rename file __file
   proc file_normalize {name} {
      unicodeNormalize FormC [__file normalize $name]
   }
   namespace ensemble create -command ::file -map {
      normalize ::file_normalize
   } -unknown {::apply {{file subcmd args} {list ::__file $subcmd} ::}}

Explanation:

1. As usual, the core [file] is renamed [__file].

2. A proc [file_normalize] is created to perform the patched [file 
normalize] operation.

3. An ensemble [file] is created. This maps the subcommand "normalize" 
to the [file_normalize] command. No other subcommands are defined, so 
everything else is passed on to the -unknown handler, which translates 
any [file] call to the corresponding [__file] call.


Lars Hellström