Paper announcement: Flexible Type Analysis

We would like to announce the availability of the following paper at URL 
http://www.cs.cmu.edu/~crary/papers/index.html or 

Stephanie Weirich
Karl Crary


Flexible Type Analysis

Karl Crary		Stephanie Weirich

Run-time type dispatch enables a variety of advanced optimization
techniques for polymorphic languages, including tag-free garbage
collection, unboxed function arguments, and flattened data structures.
However, modern type-preserving compilers transform types between
stages of compilation, making type dispatch prohibitively complex at
low levels of typed compilation. It is crucial therefore for type
analysis at these low levels to refer to the types of previous
stages. Unfortunately, no current intermediate language supports this

To fill this gap, we present the language LX, which provides
a rich language of type constructors supporting type analysis (possibly
of previous-stage types) as a programming idiom. This language is
quite flexible, supporting a variety of other applications such as analysis
of quantified types, analysis with incomplete type information, and type
classes. We also show that LX is compatible with a type-erasure