Rosetta Commatizing numbers

[Ivan Kazmenko via Digitalmars-d-learn]

On Wednesday, 31 May 2017 at 13:27:24 UTC, Solomon E wrote:

Fine, by the numbers:

> 1. pi has the commas start at the wrong digit, and doesn't 
> follow the explicit instructions to use spaces as the separator 
> and a grouping of 5

Can be solved by calling the function with a right set of 
parameters: start = 6 and step = 5.  That's what function 
parameters are for.

Here, I understand that a real-world solution would try to center 
around the decimal point.  There are, however, two reasons not to 
do so.  First, it is not required in the problem statement.  
Second, the solutions in other languages don't interpret the 
statement like that, and instead, just add a parameter to start 
reading from a certain point.  Remember that one of the main 
purposes of Rosettacode is to provide a translation from one 
language to another.  There are other places on the web for 
solving the problems in the best possible way.

> 2. There are no newlines (although the input is the list of 
> lines to be "commatized" not concatenated.)

write -> writeln

> 3. Zimbabwe dollars are given commas, against the explicit 
> request to have dots. (That would be undesirable in the real 
> world, not just in this silly example, because comma is used as 
> a decimal point in the Zimbabwe press, and spaces for thousands 
> separators.)

Can be solved by calling the function with a right set of 
parameters: ins = '.'.  That's what function parameters are for.

> 4. The second number in the line
> ===US$0017,440 millions=== (in 2,000 dollars)
> is "commatized" which is against the explicit instructions to 
> "commatize" the first number only, given in the task 
> description and explained on the task's talk page.

replaceAll -> replaceFirst

> 5. The exponent in 123.e8000 is "commatized" which is against 
> explicit and repeated instructions not to "commatize" exponents.

replaceAll -> replaceFirst

> 6. (The commas in the Eddington number are acceptable enough.)

OK.

> 7. The year in 6/9/1946 is "commatized" against explicit 
> instructions to "commatize" only the first number field. It was 
> discussed in the task's talk page that years shouldn't be 
> commatized, and that's easy to avoid by never "commatizing" 
> past the first number.

replaceAll -> replaceFirst

So, two custom calls, two minor changes, no sweat.  Is everything 
right now?  Even if not: that was fast, we can do another 
iteration.  When we have a short readable solution with no 
special cases, the first few changes are going to be easy.

> For the Eddington number, the task didn't explicitly state to 
> use spaces in that long a number, but the task does say there 
> should be spaces in the digits of pi, which leaves open to 
> interpretation whether that's a special request or a rule that 
> could apply to any sufficiently long number, AND the task 
> includes a reference to a Wikipedia page on the number that 
> does use spaces.

Here, I'd say you are greatly overthinking the problem.

> The other language solutions to Rosetta tasks may be 
> "inspirational" in some ways, but there are also errors in 
> them, at least for this task, that would be found if they were 
> fully tested. They're made by human beings, and Rosetta code is 
> just a game. It's not something that's been around as long as 
> the older languages used there have existed, to look up to 
> solutions in old languages with awe as time-worn and carved in 
> stone.

If you see a problem, ~10 solutions, and think all of them have 
serious issues, you may well be right.  But it is also likely 
that all other solution authors read the problem differently.  
Which leaves an open formal question whether you are reading it 
correctly.  As well as an open informal question whether 
enforcing your reading is a good goal, keeping in mind that 
Rosettacode is a collection of translations.

-----

If you still insist you are doing the right thing and all others 
are wrong, let's agree to disagree on that, and please just leave 
the original solution there by introducing two versions.

Ivan Kazmenko.