If I just had the HouseSize enum, then I could simplify the levels to SMALL, MEDIUM, and LARGE, but since I also have HouseEfficiency, I need to disambiguate the MEDIUM levels. Anyhow, for use in plot titles I’ve implemented a String constructor as follows:
if hs == SMALL_HOUSE
elseif hs == MEDIUM_HOUSE
I’m also aware of the string function, which turns arbitrary objects into strings by using their print methods. Should I be overloading print instead of String?
Best practice is probably to overload show instead. I’m not entirely sure how you’re using this in plot titles, but in general if you’re just interested in displaying something rather than getting a String to do further processing on, it’s probably better to use the show/display machinery.
As an additional note, any reason you can’t substitute a single enum for your two as shown below? Seems cleaner to me since the enums are representing relatively similar things. I guess if you’re really attached to displaying “small” for sizes and “low” for efficiency, that wouldn’t work.
Actually, this is a perfect use-case for defining a show method, and you almost never want to overload print (the standard definition of print is basically print(io::IO, x) = show(io, x) with error handling).
If you define Base.show(io::IO, hs::HouseSize), you can directly do plot(..., title="blah blah $size").
EDIT: As for when you might want to define print rather than show, the docstring of print says:
print falls back to calling show, so most types should just define show. Define print if your type has a separate “plain” representation.
For example, show displays strings with quotes, and print displays strings
Oh yeah, good point about the interpolation! I had a brain fart there. Though that interpolation syntax also works properly if you overload print instead of show.
To add to your quote from the docstring:
The representation used by print includes minimal formatting and tries to avoid Julia-specific details.
So it all comes down to whether I think the print/show method that I’m defining is a separate “plain” representation that avoids Julia-specific details. That’s a bit of a grey area, but in this case it seems to me that I’m defining the “plain” representation of my enum levels.
Also, of course, if I overload show it will affect printing at the REPL. In this case, I would prefer REPL printing to fall back to the show method for Enum. That won’t happen if I overload show: