I’ve posted some Swift code on github for generating nonsense words. The function patternedNonsense() generates pronounceable words like

1: hira-zansa
2: siqe-ratse
3: sifo-dassa
4: tixi-furse


The second, pureNonsense9() generates words like

1: gjoh-xkcri
2: xxgg-jjqfh
3: mxsv-tngwh
4: ftkm-aakif


Both functions use an extension to the String class that works like this

let alphabet = "abcdefghijklmnopqrstuvwxyz"
let digits = "0123456789"
alphabet.randString(4) + digits.randString(4)
// "njtu4428"


The first function makes use of diagrams, e.g.,

dgvc = ['in', 'er', 'an', 'at', 'on', 'es', 'en', 'ed', 'it', 'is',
'or', 'as', 'et', 'of', 'al', 'ar', 'ur']
dgcv = ['he', 're', 'ha', 'to', 'hi', 'ti', 'te', 'de', 'se', 'se',
'sa', 'si', 've', 'ra']


as well as a generic function randElement which returns a
random element of an array.