Align SciML Dict tuple pairs

[svchb]

Before:

algorithm_cases = Dict(
    "default search" => (),
    "with static scheduler" => (backend=StaticBackend(),),
    "with spline kernel" => (smoothing_length=1.1 *
                                              item_spacing,
                                smoothing_kernel=SplineKernel{2}())
)

After:

algorithm_cases = Dict(
    "default search"        => (),
    "with static scheduler" => (backend=StaticBackend(),),
    "with spline kernel"    => (smoothing_length=1.1 * item_spacing,
                                smoothing_kernel=SplineKernel{2}())
)

[penelopeysm]

This is another slightly nuanced one...

(1) It shouldn't join the 1.1 * item_spacing, unless join_lines_based_on_source = false. I think this is similar to previous examples we've discussed.

(2) I don't think there's any style where pair arrows are forced to align. There is the align_pair_arrow option, which you can set to true but this only aligns the pair arrows when there's pre-existing alignment. That is, if align_pair_arrow=true,

a => b
cccc => dddd

won't be converted to

a    => b
cccc => dddd

. However, if it's already in that latter format, then align_pair_arrow is supposed to make sure it doesn't revert to the former.

This does actually behave correctly (kind of) -- I've tweaked this input so that 1.1 * item_spacing is on the same line, and added a few more spaces to the default search line to enable the custom alignment heuristic

julia> s = """
       algorithm_cases = Dict(
           "default search"        => (),
           "with static scheduler" => (backend=StaticBackend(),),
           "with spline kernel" => (smoothing_length=1.1 * item_spacing,
                                       smoothing_kernel=SplineKernel{2}())
       )
       """
"algorithm_cases = Dict(\n    \"default search\"        => (),\n    \"with static scheduler\" => (backend=StaticBackend(),),\n    \"with spline kernel\" => (smoothing_length=1.1 * item_spacing,\n                                smoothing_kernel=SplineKernel{2}())\n)\n"

julia> s |> println
algorithm_cases = Dict(
    "default search"        => (),
    "with static scheduler" => (backend=StaticBackend(),),
    "with spline kernel" => (smoothing_length=1.1 * item_spacing,
                                smoothing_kernel=SplineKernel{2}())
)

julia> format_text(s, SciMLStyle(); align_pair_arrow=true) |> println
algorithm_cases = Dict(
    "default search"        => (),
    "with static scheduler" => (backend = StaticBackend(),),
    "with spline kernel"    => (smoothing_length = 1.1 * item_spacing,
    smoothing_kernel = SplineKernel{2}())
)

So the alignment is behaving correctly, although the indentation of smoothing_kernel is probably not right -- it should be indented one more level.

All in all, I think there are some bugs here, but I'm not sure they're the same bugs that the PR tries to fix.

[penelopeysm]

There could also be a flag that says "yes really force the alignment even if it's not already aligned to begin with" -- that'd be a separate config option though that would apply across all styles.