commit faba6ef9c828a6d932a0c582c280bcecc80359c4
parent 59cbe9bf97f34d4fd481362e0e77caa1d40fcb2d
Author: Georges Dupéron <georges.duperon@gmail.com>
Date: Wed, 7 Jun 2017 19:58:31 +0200
Used abbreviations for PHOAS and HOAS
Diffstat:
3 files changed, 24 insertions(+), 12 deletions(-)
diff --git a/scribblings/abbreviations.rkt b/scribblings/abbreviations.rkt
@@ -1,5 +1,6 @@
#lang at-exp racket
-(provide typedracket Typedracket csharp CAML CLOS NIT CPP DeBruijn)
+(provide typedracket Typedracket csharp CAML CLOS NIT CPP DeBruijn HOAS PHOAS
+ monocecil dotnet DLL)
(require scribble/base
scribble/core
@@ -26,3 +27,9 @@
(define NIT "NIT")
(define CPP "C++")
(define DeBruijn "De Bruijn")
+;; TODO: make it an <abbr> and give it a tooltip in HTML
+(define HOAS "HOAS")
+(define PHOAS "PHOAS")
+(define monocecil @tt{"Mono.Cecil"})
+(define dotnet ".NET")
+(define DLL "DLL")
+\ No newline at end of file
diff --git a/scribblings/introduction.scrbl b/scribblings/introduction.scrbl
@@ -176,7 +176,15 @@
bugs: name clashes can occur if the qualification chosen is not sufficient
to always distinguish nodes; @htodo{furthermore} compiler passes which
duplicate nodes (for example specialising functions) or merge them must be
- careful to correctly update identifiers.}
+ careful to correctly update identifiers.
+
+ Anecdotally, we can mention a bug in the @|monocecil| library (which allows
+ easy manipulation of @|dotnet| bytecode). When ``resolving'' a reference to
+ a primitive type, it can happen in some cases that @|monocecil| returns a
+ @tt{Type} metadata object which references a type with the correct name, but
+ exported from the wrong @|DLL| library.
+
+}
@item{Alternatively, backward references may be encoded as a form of path
from the referring node. @DeBruijn indices can be used in such an encoding,
for example.
@@ -211,21 +219,21 @@
as the computation of the various parts of the data manipulated do not occur
in an intuitive order. Among other things, accidental infinite recursion
could be triggered by an access to a value by totally unrelated code.}
- @item{Finally, Higher-Order Abstract Syntax, or HOAS for short, is a
+ @item{Finally, Higher-Order Abstract Syntax, or @|HOAS| for short, is a
technique which encodes variable bindings as anonymous functions in the host
language (whose parameters reify bindings at the level of the host
language). Variable references are then nothing more than actual uses of the
variable at the host language's level. Substitution, a common operation in
compilers and interpreters, then becomes a simple matter of calling the
- anonymous function with the desired substitute. HOAS has the additional
+ anonymous function with the desired substitute. @|HOAS| has the additional
advantage that it enforces well-scopedness, as it is impossible to refer to
a variable outside of its scope in the host language.
- Parametric HOAS, dubbed PHOAS, also allows encoding the type of the
+ Parametric @|HOAS|, dubbed @|PHOAS|, also allows encoding the type of the
variables in the representation. @todo{Can extra information other than the
type be stored?}
- There are a few drawbacks with HOAS and PHOAS:
+ There are a few drawbacks with @|HOAS| and @|PHOAS|:
The ``target'' of a backward reference must be above all uses in the tree.
This might not always be true. For example, pre/post-conditions could, in an
@@ -242,7 +250,7 @@
support this should be feasible.}
}
- @todo{PHOAS naturally lends itself to the implementation of substitutions,
+ @todo{@|PHOAS| naturally lends itself to the implementation of substitutions,
and therefore is well-suited to the writing of interpreters. However, the
representation cannot be readily traversed and accesses like would be done
with normal structures, and therefore the model could be counter-intuitive
@@ -259,9 +267,6 @@
objects), they still involve low-level mechanisms to create the graph;
furthermore code traversing the graph needs to be deal with cycles, in order
to avoid running into an infinite loop (or infinite recursion).
-
- anecdotally
-
updates: all logical pointers to an updated node must be updated too.
diff --git a/scribblings/state-of-the-art.scrbl b/scribblings/state-of-the-art.scrbl
@@ -550,8 +550,7 @@
pointers}
@item{The huet zipper@~cite["huet1997zipper"]. Implementation in untyped
Racket, but not @|typedracket|@note{
- @url{http://docs.racket-lang.org/zippers/}
- @(linebreak)
+ @url{http://docs.racket-lang.org/zippers/} and
@url{https://github.com/david-christiansen/racket-zippers}}}]
}
}
\ No newline at end of file
