[fpc-pascal] Read lines into UnicodeString variable from UCS2 (UTF-16) encoded text file

[Tomas Hajny]

On 2019-09-16 00:29, DougC wrote:


Doug,

  .
  .
> I do not like item 3 in that the function, as described, is named
> DetectUtfBom but does more than detect. Side effects of functions are
> generally not good. I would at least rename it something like
> DetectAndHandleUtfBom.

Take the provided names just as my proposal, I can imagine that there 
may be better alternatives.


> But to fully correct the situation, I would also change it to a
> procedure since leaving it as a function still suggests it only
> returns a result and has no other side effects.

No, changing it to a procedure would not work - the information whether 
BOM was found and thus the codepage in the text file record was set 
accordingly, or whether the information was not available, is very 
important for further processing (as an example, the programmer may ask 
the end user to provide information about the text file encoding in such 
a case). Purely from technical point of view, it would be possible to 
change it to a procedure and move the return value to a new actual 
parameter, but it doesn't make much sense from my point of view.

Tomas



> ---- On Sun, 15 Sep 2019 18:20:22 -0400 Tomas Hajny
> <XHajT03 at hajny.biz> wrote ----
> 
> 
> 3) New function 'DetectUtfBom (var T: text): boolean' will be added.
> This function may be called after the call to 'Reset (T: text)' to 
> check
> for existence of BOM at the beginning of the text file. If it is found
> (Result=true), SetTextCodePage is invoked automatically from
> DetectUtfBom with the codepage value corresponding to the found BOM and
> encoding variant. If BOM is not found (Result=false), nothing changes.