Fix contract for lookup-typed/lexical.
Default cases for printing.
Abstract out indexing functions for Nat/Integer split.
svn: r17272
original commit: d0c8a19ce84ce1ef674c1c43e69b56ee7e0a63a2
Special handling of (letrec ([x e]) x)
Allow functions with optional keyword args to be inferred when kws not supplied.
Infer instantiations for kw functions in simple cases.
Add `Path-String' type
Fix types of `filter', `with-{input-to,output-from}-file'
Add `port->lines'
New 'metrics.ss' test
svn: r16385
original commit: 37106bd6f7241277288ad56a3c75aef53cdfc3c3
