I agree that something like arrow_size and arrowsize shouldn't coexist. I'm not sure if I agree with having underscores everywhere or nowhere. I think there are some cases where underscores help readability and others where it's better without. That being said I also find myself wondering sometimes whether there is an underscore in an attribute name or not. Maybe we could keep it to a select few prefixes without underscore (like is, has, min, max, single characters) and use underscores consistently otherwise?

The Julia style guide also suggests having no underscores for simple names. Though that is rather subjective...

functions are lowercase (maximum, convert) and, when readable, with multiple words squashed together (isequal, haskey). When necessary, use underscores as word separators. Underscores are also used to indicate a combination of concepts (remotecall_fetch as a more efficient implementation of fetch(remotecall(...))) or as modifiers.

I think we followed that rule that underscores come in only when they are needed for readability. What could help additionally would be erroring on nonexistent keyword attributes and giving suggestions. Then one could quickly find misspelled variants.

I think we followed that rule that underscores come in only when they are needed for readability.

Right but I'm not sure it works in practice because "needed for readability" is so subjective. So now the result is that it's difficult to guess when there should be an underscore. Who would guess that patchstrokecolor needs no underscore but nan_color does? Or roundedrectpoints vs t_segments, or notchmin vs k_min?

It would be great to make this more predictable.

Maybe we could keep it to a select few prefixes without underscore (like is, has, min, max, single characters) and use underscores consistently otherwise?

Yes I think something in this direction is a good idea: identify some "grammar" rules that work well. Looking at the existing keywords, it seems that underscores are most often used in the following cases:

1. Around verbs and prepositions
2. To separate plot elements from other-level things such as "mouse" and "key".

I think both rules make a lot of sense:

1. The first rule is often required to make things readable: the least readable keywords are often due to mixing nouns with verbs and prepositions without delimiters. For example fliplabelsat reads much worse than the current flip_labels_at.
2. The second rule is quite intuitive (more strongly separating things that are on a different level). It's also consistent with the style guide quoted by @jkrumbiegel (_ to indicate a "combination of concepts").

Let's see what happens if we apply the suggested rules: use underscores systematically around verbs and prepositions and other-level things (like "mouse"), and never otherwise.

Click to expand the list at the bottom to see all the Makie keywords (probably not an exact list) with

• the result of the rules in the left column,
• the original keyword in the right column (empty when the original already agrees with the rules).

I think the suggested list really makes things more consistent and predictable without hurting readability. In a couple of cases it would make things worse, but then it can make sense to further change the keyword:

• k_ideal should become kideal, maybe a bit odd but we could use kbest instead.
• For marker_neg, marker_pos I propose markernegative and markerpositive (it also removes the ambiguity that "pos" could mean "position").
• For ranges_labels maybe use ranges_and_labels.

Note: I removed over_background_color and over_bar_color which are listed in hist.jl but look like bugs (it should be color_over_background and color_over_bar as in barplot.jl).

What do you think?

This just tripped me up as well. Furthermore it seems, that e.g. for Legend no keyword checks are in place. So having label_font like in Figure just changes nothing...

Related: #2519, #2520

Ok, since this has been converted to a discussion, let's discuss. I like the proposed changes and have only four points: 1) Keep flip_vertical_label as is or remove all underscores, flip_verticallabel looks odd to me. 2) Keep selectionbutton. 3) Remove underscores for show*. 4) One might consider outlinestyle and outlinewidth instead of the double outlineline*.