caster contractions

        "contraction <text> will":
            R(Text("%(text)s'll ")),
        "cap contraction <text> will":
            R(Function(lambda text:Text(text.capitalize() + "'ll ").execute())),
        "contraction <text> have":
            R(Text("%(text)s've ")),
        "cap contraction <text> have":
            R(Function(lambda text:Text(text.capitalize() + "'ve ").execute())),
        "contraction <text> are":
            R(Text("%(text)s're ")),
        "cap contraction <text> are":
            R(Function(lambda text:Text(text.capitalize() + "'re ").execute())),
        "contraction <text> is":
            R(Text("%(text)s's ")),
        "cap contraction <text> is":
            R(Function(lambda text:Text(text.capitalize() + "'s ").execute())),
        "contraction <text> not":
            R(Text("%(text)s't ")),
        "cap contraction <text> not":
            R(Function(lambda text:Text(text.capitalize() + "'t ").execute())),
        "contraction <text> (do|would)":
            R(Text("%(text)s'd ")),
        "cap contraction <text> (do|would)":
            R(Function(lambda text:Text(text.capitalize() + "'d ").execute())),

Thanks for sharing, Just a small suggestion,in order to avoid having many specs, you could try to have a Choice element, say "continuation" or what ever you want to name it that would be like

Choice("continuation", {
    "(do|would)":"'d",
    "not":"'nt",
...
}

And you could do like

"contraction <text> <continuation>":R(Text("%(text)s%(continuation)"))

That's cool, I didn't know I could do that.

"contraction <text> <continuation>":R(Text("%(text)s%(continuation)"))

Should this have an s before the end quote?

Yes it does! sr for typo