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Wrote more about the show-mhshow merge.
author markus schnalke <meillo@marmaro.de>
date Sat, 02 Jun 2012 12:00:22 +0200
parents 4c9f4d05d90e
children bae9273b5802
comparison
equal deleted inserted replaced
68:7ca31b06b653 69:f80ced4e749b
269 Therefore they were removed. 269 Therefore they were removed.
270 270
271 271
272 .H2 "Merge of \f(CWshow\fP and \f(CWmhshow\fP 272 .H2 "Merge of \f(CWshow\fP and \f(CWmhshow\fP
273 .P 273 .P
274 Since the very beginning, already in the first concept paper, 274 Since the very beginning \(en already in the first concept paper \(en
275 .Pn show 275 .Pn show
276 had been MH's message display program. 276 had been MH's message display program.
277 .Pn show 277 .Pn show
278 found out which pathnames the relevant messages had and invoked 278 found out which pathnames the relevant messages had and invoked
279 .Pn mhl 279 .Pn mhl
285 .Pn show 's 285 .Pn show 's
286 simple approach and 286 simple approach and
287 .Pn mhl 's 287 .Pn mhl 's
288 limited display facilities couldn't cope with the task any longer. 288 limited display facilities couldn't cope with the task any longer.
289 .P 289 .P
290 Instead of extending these tools, new ones were written from scratch 290 Instead of extending these tools, additional ones were written from scratch
291 and then added to the MH tool chest. Doing so is encouraged by the 291 and then added to the MH tool chest. Doing so is encouraged by the
292 tool chest approach. The new tools could be added without interfering 292 tool chest approach. The new tools could be added without interfering
293 with the existing ones. This is great. The ease of adding new tools 293 with the existing ones. This is great. The ease of adding new tools
294 even made MH the first MUA to implement MIME. 294 even made MH the first MUA to implement MIME.
295 .P 295 .P
301 With the 1.0 release of nmh in February 1999, Richard Coleman finished 301 With the 1.0 release of nmh in February 1999, Richard Coleman finished
302 the split of 302 the split of
303 .Pn mhn 303 .Pn mhn
304 into a set of specialized programs, which together covered the 304 into a set of specialized programs, which together covered the
305 multiple aspects of MIME. One of these resulting tools was 305 multiple aspects of MIME. One of these resulting tools was
306 .Pn mhshow . 306 .Pn mhshow ,
307 .Pn mhshow 307 which replaced the
308 resembled the
309 .Cl "mhn \-show 308 .Cl "mhn \-show
310 call. 309 call.
311 .P 310 .P
311 From then on, two message display tools were part of nmh.
312 Because it should not require user actions to invoke the right tool
313 whether the message uses MIME or not,
314 .Pn show
315 was extended to automatically hand the job over to
316 .Pn mhshow
317 if displaying the message would be beyond
318 .Pn show 's
319 abilities.
320 For convenience,
321 .Pn show
322 would still display MIME messages if they contained only a single text
323 part.
324 In consequence, the user would invoke
325 .Pn show
326 (possibly through
327 .Pn next
328 or
329 .Pn prev )
330 and get the message printed with either
331 .Pn show
332 or
333 .Pn mhshow ,
334 whatever was more appropriate.
335 (There was also a switch for
336 .Pn show
337 to never invoke
338 .Pn mhshow .)
339 .P
340 Having two similar tools for essentially the same task is redundant.
341 Both programs needed to be developed syncronously as they were
342 used as a single tool by the user. Thus they needed to act in a
343 similar way to not distract the user.
344 .P
345 Today, non-MIME messages are rather seen to be a special case of
346 MIME messages, than MIME messages are seen to be an extension to
347 original mail.
348 As
349 .Pn mhshow
350 had already be able to display non-MIME messages, it was natural
351 to drop
352 .Pn show
353 in favor of using
354 .Pn mhshow
355 exclusively.
356 .Ci 4c1efdd
357 This decision follows the idea of orthogonal design.
358 .P
359 To allow this replacement,
360 .Pn mhshow
361 was reworked to behave more like
362 .Pn show
363 first.
364 Section XXX describes this rework from a different perspective.
365 Once the tools behaved similar, the replacing became a natural decision.
366 In mmh,
367 .Pn show
368 is the one single message display program again, but it handles
369 MIME messages as well as non-MIME messages.
370 There's only one program to maintain and users don't need to deal
371 with the existance of two display programs.
372 .P
373 Though, there's one reason why removing the old
374 .Pn show
375 hurts: It had been such a simple program.
376 Its lean elegance is missing to
377 .Pn mhshow ,
378 i.e. the new
379 .Pn show .
380 But there is no chance, because supporting MIME causes essentially
381 higher complexity.
312 382
313 383
314 .H2 "Removal of Configure Options 384 .H2 "Removal of Configure Options
315 .P 385 .P
316 386