Fooling around with using Python's parsley to generate Swift code.

ab.py

#!/usr/bin/env python

# fooling around with using parsley to generate swift.

import parsley

x = parsley.makeGrammar("""
ab = <'a'+>:a <'b'+>:b -> (a,b)
""", {})

print """
struct AB {
    let a: String
    let b: String
}
"""

# output: let ab1 = AB(a: "a", b: "b")
ab = x("ab").ab()
print 'let ab1 = AB(a: "%s", b: "%s")' % (ab[0], ab[1])

# output: let ab2 = AB(a: "aaa", b: "bbb")
ab = x("aaabbb").ab()
print 'let ab2 = AB(a: "%s", b: "%s")' % (ab[0], ab[1])