`TREMLEntities.MapToEntity` doesn't perform per description

[delphidabbler]

codesnip/Src/UREMLDataIO.pas

Line 904 in 02656b8

class function TREMLEntities.MapToEntity(const Ch: Char): string;

Description says this function returns the character itself if it is printable ASCII, but it returns the empty string in this case.

[delphidabbler]

Need to check how this method is used. If calling code depends on out of spec behaviour then update comments else correct the code.

[delphidabbler]

TREMLEntities.MapToEntity gets called from this method:

codesnip/Src/UREMLDataIO.pas

Line 655 in 02656b8

function TREMLWriter.TextToREMLText(const Text: string): string;

This code tests the method's return value against the empty string, so this is what it is expecting.

So, it looks like the method acts as expected and the comments are wrong.

I think the actual behaviour is reasonable because the code is supposed to be return an entity if one exists. Furthermore, the calling code has to wrap the entity between & and ; characters, so the empty string result is useful to help deciding if this should be done.

Maybe renaming to MapToEntityIfExists would clarify.

[delphidabbler]

The comments for both TREMLEntities.MapToEntity and the private TREMLEntities.CharToMnemonicEntity methods were changed to reflect their actual functions.