Compiling with Continuations by Andrew W. Appel, published by Cambridge University Press, 1992, is a classic text in the area of compiler construction. It describes the backend of the Standard ML of New Jersey compiler, which uses the continuation passing style (CPS) compilation strategy.
The implementation language used in the book is also ML. This repository is an alternative implementation in Rust. Effort was made to stay as close to the book as was reasonable. Because Rust is in some sense a strict superset of ML, most of the data structures translated with only minor syntactic changes. Some of the names have been changed for increased clarity.
Some notes on analogous types and data structures between this code and [Appel] are collected here.
| Name | ML Item | ML Type | Rust Item | Rust Type |
|---|---|---|---|---|
| Value | Value | datatype value = VAR of var |
LABEL of var |
INT of int |
| Values | - | - | ValueList |
Vec<Value> |
| Continuation | Continuation Expression | CExp |
CExp |
|
| Name | ML item | ML type | Rust item | Rust type |
|---|---|---|---|---|
| Denotable Values | dvalue list |
dvalue list |
DValueList / DenotableValueList |
Vec<DenotableValue> |
| Parameters | - | - | Parameters, wrapper for DValueList |
Rc<DValueList> |
| Store | store: (next unused, value store, integer store) |
loc * (loc -> dvalue) * (loc -> int) |
Store |
struct Store{ next_unused_address: Location, current_exception_handler: Location, values: DenotableValueList, integer_values: IntegerList } |
| Continuation | dvalue FUNC |
dvalue list -> store -> answer |
RawContinuation |
dyn Fn(Parameters, Store) -> Answer |
| Continuation | - | - | Continuation / DenotableFunction, wrapper for RawContinuation |
pub struct Continuation{pub f: Rc<RawContinuation>} |
| Answer | Curried continuation: f [p1 p2 ...] (no store) |
store -> answer |
Answer |
pub struct Answer {f: Rc<RawContinuation>, parameters: Parameters} |
| Current Exception Handler | Global variable | val handler_ref : loc |
Member of Store |
struct Store{ current_exception_handler: Location, ... } |
ContinuationExpression evaluates to Continuation (DenotableFunction) evaluates to Answer.
Copyright (C) 2022 Robert Jacobson. This software is distributed under the MIT license or the Apache license at your option. See MIT.txt and APACHE.txt.
The book Compiling with Continuations by Andrew W. Appel is Copyright (C) 1992 Cambridge University Press. Quotations from this work are included herein under the "fair use" exceptions of Section 107 of the Copyright Act.
Standard ML of New Jersey is Copyright (c) 2001-2020 by The Fellowship of SML/NJ and Copyright (c) 1989-2001 by Lucent Technologies. No code from Standard ML of New Jersey was used in this project.