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Design #476

Review utility of package IO

Added by John Abbott about 10 years ago. Updated about 2 years ago.

Status:
In Progress
Priority:
Low
Assignee:
Anna Maria Bigatti
Category:
Cleaning
Target version:
CoCoA-5.4.2
Start date:
14 Mar 2014
Due date:
% Done:

40%

Estimated time:
Spent time:
2.65 h

Description

Package io does not do much currently; can we eliminate it?

History

#1 Updated by Anna Maria Bigatti about 10 years ago

  • Target version set to CoCoA-5.1.0 Easter14

#2 Updated by John Abbott about 10 years ago

  • Target version changed from CoCoA-5.1.0 Easter14 to CoCoA-5.1.1 Seoul14

#3 Updated by Anna Maria Bigatti almost 10 years ago

  • % Done changed from 0 to 10

At the moment it is only exporting format (which I find quite useful).
I updated Format/format and checked the manual.

Another function defined there is StarPrintFold: now StarPrint is no longer needed, but the Fold part can still be useful.

#4 Updated by Anna Maria Bigatti over 9 years ago

  • Assignee set to Anna Maria Bigatti
  • Priority changed from Normal to Low
  • Target version changed from CoCoA-5.1.1 Seoul14 to CoCoA-5.?.?

I don't think we should eliminate it.
In time, we can see what can be useful and advertized (low priority)

#5 Updated by John Abbott over 6 years ago

  • Status changed from New to In Progress

Indeed some form of "folded" printing could be useful for large outputs (especially inside emacs which has problems with long lines).

Currently StarPrintFold does not work, but the manual suggests that it should work.
Anna correctly points out that the fn is not exported from the package, but attempting to call StarPrintFold does indeed produce the suggestion to use the name $io.StarPrintFold

It should not be too hard to revise the package so that StarPrintFold works. I wonder what the name of the fn should be; the Star part is no longer necessary.

#6 Updated by John Abbott about 5 years ago

  • Target version changed from CoCoA-5.?.? to CoCoA-5.3.0

JAA thinks we can remove StarPrint and StarPrintFold from the CoCoA-5 manual (and also from io.cpkg5)

It might be useful to have a fold function for a string: it would take a string and a width, and then
print out the string trying not to exceed the given width (I'm not yet clear what the semantics should be).

#7 Updated by Anna Maria Bigatti about 5 years ago

John Abbott wrote:

JAA thinks we can remove StarPrint and StarPrintFold from the CoCoA-5 manual (and also from io.cpkg5)

It might be useful to have a fold function for a string: it would take a string and a width, and then
print out the string trying not to exceed the given width (I'm not yet clear what the semantics should be).

I agree.
Indeed StarPrint appears as "not yet implemented", so we could just remove it.
And I also agree that the fold function could be useful.
I'll have a look.

#8 Updated by John Abbott about 5 years ago

I have just looked quickly on internet for information about the unix command fold:
  • it seems there are three similar utilities: fold which inserts newlines after every K characters, fmt which inserts newlines next to whitespace, and par which is purportedly "smarter" than fmt
  • at the moment my preference is for a function which takes a string and returns a string (rather than a procedure which takes a string and prints directly); a user who calls the function at top-level will probably not notice a difference (unless the string is very long).

I think it may be reasonable to offer two functions: one like fold (simple, easy to understand, but may insert newlines in "funny places"), and one like fmt (or par) which inserts newlines only in "nice" places (e.g. next to whitespace). The latter function might be useful for printing out large polynomials in a slightly more readable way (but who want to read such a large poly anyway?)

The two functions might even have the same name:
  • perhaps with an extra parameter saying what strategy to use for inserting spaces?
  • perhaps it works like fold if the arg is a string, and works like fmt if the arg is ringelem (or list or matrix or ???)

#9 Updated by John Abbott about 5 years ago

What about the other junk in io.cpkg?

  • format is exported
  • SprintTrunc appears in the CoCoA-5 manual, but it is not exported, and does not seem to be used in any package... Delete it?
  • Print_Aliases is obsolete?
  • Print_Table seems like a nice function (but old-fashioned name)
  • Print_Matrix looks dodgy to me
  • Tagged !! shouldn't this give a syntax error?

#10 Updated by Anna Maria Bigatti about 5 years ago

  • % Done changed from 10 to 30

John Abbott wrote:

What about the other junk in io.cpkg?

  • format is exported

and is used

  • SprintTrunc appears in the CoCoA-5 manual, but it is no exported, and does not seem to be used in any package... Delete it?

In the manual, but "NOT YET IMPLEMENTED", and indeed does not work.

  • Print_Aliases is obsolete?

I'd say yes.

  • Print_Table seems like a nice function (but old-fashioned name)

We wrote a PrintTable for a matrix in experimental.cpkg.
Should we move it to io.cpkg5? to mat.cpkg5?

/**/ PrintTable(StdDegRevLexMat(4));
/**/ PrintTable(StdDegRevLexMat(4), 1);

  • Print_Matrix looks dodgy to me

I agree, and the new one is more flexible.

  • Tagged !! shouldn't this give a syntax error?

no, it is not exported.
(that was our choice in the cocoa5 language for making packages less painful than cocoa4).
This was common in packages with tags to avoid overwriting them.
Pointless now, as we changed the printing philosophy (see PrintRes, PrintBettiMatrix,..).

Instead, if you think of the recursion, it does say "Too many nested scopes" (after fixing other things)

#11 Updated by John Abbott over 4 years ago

  • Target version changed from CoCoA-5.3.0 to CoCoA-5.4.0

If the package exports only format, perhaps that package name should be changed to format?

#12 Updated by John Abbott about 4 years ago

  • % Done changed from 30 to 40

I have implemented a fold function in CoCoALib, and exported it to CoCoA-5.

I have not implemented a "smart" fold fn; it would be considerably more complicated, and I'm not sure it would really be that much more useful.

#13 Updated by John Abbott about 2 years ago

  • Target version changed from CoCoA-5.4.0 to CoCoA-5.4.2

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