LambdaFree - MLton Standard ML Compiler (SML Compiler)

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LambdaFree is an analysis pass for the SXML IntermediateLanguage, invoked from ClosureConvert.

## Description

This pass descends the entire SXML program and attaches a property to each `Lambda` `PrimExp.t` in the program. Then, you can use `lambdaFree` and `lambdaRec` to get free variables of that `Lambda`.

## Implementation

lambda-free.sig lambda-free.fun

## Details and Notes

For `Lambda`s bound in a `Fun` dec, `lambdaFree` gives the union of the frees of the entire group of mutually recursive functions. Hence, `lambdaFree` for every `Lambda` in a single `Fun` dec is the same. Furthermore, for a `Lambda` bound in a `Fun` dec, `lambdaRec` gives the list of other functions bound in the same dec defining that `Lambda`. For example:

    val rec f = fn x => ... y ... g ... f ...
    and g = fn z => ... f ... w ...

     * lambdaFree(fn x =>) = [y, w]
     * lambdaFree(fn z =>) = [y, w]
     * lambdaRec(fn x =>) = [g, f]
     * lambdaRec(fn z =>) = [f]

Last edited on 2006-11-02 17:37:38 by MatthewFluet.