First, make statement structure richer. Instead of just String, make its' parameter a list of something like this:

data SExpr = Underscore | Word String

and Stmt thus:

data Stmt = Stmt [SExpr]

This way it is easier to construct and/or combine.

Second, make graph operations to operate on bulk of data. Singleton data is a special case of bulk data and bulk operations are much more efficient in general.

So instead of addRelIdxToNode :: RelIdx -> Node -> Node create something like addRelIdxToNodes :: RelIdx -> [Node] -> [Node] (use your collection of choice instead of lists).

This will pay rather quickly (in terms of performance and brevity).

Those are my two humble suggestions.

2015-07-17 9:19 GMT+03:00 Jeffrey Brown <jeffbrown.the@gmail.com>:

I'm writing a graph class that generalizes the traditional mathematical graph: Nodes can be statements or relationships, and relationships ("edges") can involve any number of nodes, including other relationships. [1] describes the motivation in a little more detail.

[2] explains the idea behind the major types -- Graph, Node, Stmt, and Rel.

Of the .hs files in the project, at this time I believe only the primary one, Dwt.hs [3], deserves your attention. It is only about 100 lines of code.

I am interested in any kind of feedback at all, no matter how minute in detail or expansive in scope.

[4] lists what I already think might be likely problems and solutions. In particular I wonder whether I should interpret these two patterns:
"case ni of Rel -> .. Stmt -> .."
and
"if (Maybe.isJust nMb) ... else error ..."
as signs that I'm not completely solving the problem.

I suspect it might be helpful to make the graph operations Maybe or Either, and use <|> on them -- but while I can monkey those words, I don't really know what I'm saying.

[1] https://github.com/JeffreyBenjaminBrown/digraphs-with-text/blob/master/english/motivation.txt
[2] https://github.com/JeffreyBenjaminBrown/digraphs-with-text/blob/master/english/how_it_works.txt
[3] https://github.com/JeffreyBenjaminBrown/digraphs-with-text/blob/master/src/Dwt.hs
[4] https://github.com/JeffreyBenjaminBrown/digraphs-with-text/blob/master/english/todo%2Cmaybe.txt

Thank you,
Jeff

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