consistency.md

Data Intellect KDB-X Module Consistency Guide

module Contents

Every module must have:

1. The code
2. Documentation in a .md file
3. Tests, conforming to k4unit

The tests should be runnable as

q)k4unit:use`k4unit
q)k4unit.moduletest`module_to_test

Paths

Use module local paths for loading and file references

/ local loading
\l ::local/path/to/file.q

/ local path
get`:::local/path/to/datafile

Export

Only export the functions which should be called externally.

Namespaces

Avoid \d namespace switches.

Injectable Dependencies

Pass dependencies as a single dict to init — this keeps the signature stable as more injectables are added. All dependencies are required; init must error immediately with a clear message if any are absent. Store each injected function in .z.m and always call it through .z.m at call sites.

/ mymodule.q
init:{[deps]
  / deps - `log!(logdict) or `log`timer!(logdict;timerdict)
  /   `log: `info`warn`error!({[c;m]};{[c;m]};{[c;m]}) - required
  / examples:
  /   mymodule.init[enlist[`log]!enlist logdep]
  logdict:$[99h=type deps;$[(`log in key deps) and not (::)~deps`log;deps`log;()!()];()!()];
  if[not count logdict;
    '"di.mymodule: log dependency is required; pass `info`warn`error functions - see di.log or refer to confluence documentation";
  ];
  .z.m.loginfo:logdict`info;
  .z.m.logwarn:logdict`warn;
  .z.m.logerr:logdict`error;
  };

myfunc:{[x]
  .z.m.loginfo[`mymodule;"processing ",string x];
  };

Callers provide a dict of functions. Use di.log if no custom logger is needed:

log:use`di.log
logdep:`info`warn`error!(log.info;log.warn;log.error)
mymodule.init[enlist[`log]!enlist logdep]