Scatter-gather documentation errors

[jmarshall]

The “Defining scatter-gather processes” documentation in docs/snakemake/rules.rst says

Thereby, scatter.split("splitted/{scatteritem}.txt") yields a list of paths "splitted/1-of-n.txt", "splitted/2-of-n.txt", …, depending on the number n of scatter items defined. Analogously, gather.split("splitted/{scatteritem}.post.txt"), yields a list of paths "splitted/0.post.txt", "splitted/1.pos.txt", …, which request the application of the rule intermediate to each scatter item.

For this to work, one assumes that both gather.split and scatter.split would need to generate the same list of filenames. So surely either both of them should be of the form 1-of-n, 2-of-n, etc or both of them should be of the form 0, 1, …, n-1.

There is also a minor typo: 1.pos.txt.

It would also be useful if the documentation noted the Snakemake version in which this facility became available, which appears to be v5.25.0.

[leonqli]

Any practical example of using scatter/gather.split? In the documentation, the "rule split" has no input file. Is it possible to split an input file into n parts, using linux command, split -n -d? Thanks!

[jmarshall]

PR #1441 fixed the minor typo, but the filename inconsistency remains.