This is a partial re-implementation of #59645
oranges has expressed a desire for the span_ procs to instead be macros.
I agree. Even though it's a small micro-optimisation, a well contained macro can be self-linting. I've already caught one edge case thanks to this in launch_pad.dm
Similarly, there was an edge case where a [ was escaped inappropriately (that errored out) in watercloset.dm and a case where a ] that should probably have been escaped actually wasn't in robot_defense.dm
I have opted to make an exception to the ALLCAPS convention for these macros.
I have guaraded these macros in parenthesis. In doing so, additional error states can be captured as part of the build process as malformed inputs will then cause errors and prompt further investigation.
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