[bug] Pin case sensitivity.

[zombielinux]

I'm looking at implementing this but I use a lot of mil-circ connectors.

As such, they typically run A-Z, then a-z, then I think aa-zz.

As it stands, defining the template:

   - &MS3126F18-32P
     type: MS3126F18-32P
     pins: [A, B, C, D, E, F, G, H, J, K, L, M, N, P, R, S, T, U, V, W, X, Y, Z, a, b, c, d, e, f, g, h, j]

And then using pin "a" actually connects pin "A". In my case, these are VERY different pins. This is with the latest dev branch.

[kvid]

Thank you for reporting this bug. It seems WireViz is case sensitive about identifiers, but unfortunately Graphviz is not. This also means that a similar identifier problem might occur when a connector/cable name is not case insensitive unique.

I suggest keeping WireViz case sensitive to allow use cases like yours, and use pin index instead of pin name in all connector port identifiers to ensure their uniqueness. If it is really important to keep the pin name in the port identifier, then it might be appended as a suffix to the pin index when different from it.

[formatc1702]

Here's a quick test that displays the observed behavior:

connectors:
  X1:
    pins: [AA, Aa, aA, aa]
  X2:
    pins: [ZZ, Zz, zZ, zz]

cables:
  W1:
    wirecount: 4
    color_code: DIN

connections:
  -
    - X1: [AA, Aa, aA, aa]
    - W1: [1-4]
    - X2: [zz, ZZ, Zz, zZ]

Expected result:

Actual result:

Workaround to display expected result:
Replace A with _A_ and Z with _Z_ in GraphViz file.
This is obviously not the solution to the underlying issue; just leaving this here for reference.

[formatc1702]

I suggest keeping WireViz case sensitive to allow use cases like yours, and use pin index instead of pin name in all connector port identifiers to ensure their uniqueness.

+1 👍

[formatc1702]

The safest approach is to use an internally assigned, numerical, auto-incremented ID to every pin (analogously, assign a similar ID to every wire in a cable to iterate over) and map the user-specified pin ID to this internal one.

In the typical case where a user does not specify a connector's pins directly, and they are thus auto-numbered, the internal ID and the "user-visible" ID used when defining a connection will simply be the same.

In the above mentioned case, Python/WireViz will case-sensitively match the user-provided pins to their respective unambiguous numerical IDs.

This also solves a semi-related issue:
When using pins with unusual characters (<,> and others), GraphViz is unable to draw the edges because the port names it uses to attach the edge to a node currently contain the pins attribute, causing issues with GraphViz' internal HTML when pins contains such illegal characters.
See #230 for this issue.