Logfmt

Logfmt provides a logfmt(object) method on String instances to easily format any input object into logfmt.

Example:

let memoryContext = ["memory":
                        ["current": ["footprint": 128,
                                     "available": 2000 - 128,
                                     "limit": 2000],
                         "peak": ["footprint": 348,
                                  "available": 2000 - 348,
                                  "limit": 2000]]]
let formatted = String.logfmt(memoryContext)
print(formatted)

will output:

memory.current.available=1872 memory.current.footprint=128 memory.current.limit=2000 memory.peak.available=1652 memory.peak.footprint=348 memory.peak.limit=2000

The Logfmt class is in progress will eventually help integrate apple's Logging framework.