From 8ec0a2193fa53fd7bc15c2118e676f82e904f493 Mon Sep 17 00:00:00 2001
From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Fri, 4 Dec 2009 22:56:15 +0100
Subject: [PATCH] Add section on EDSLs.

---
 Chapters/Context.tex | 37 ++++++++++++++++++++++++++++++++++---
 Utils/Lambda.tex     | 13 +++++++++++++
 2 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/Chapters/Context.tex b/Chapters/Context.tex
index 9213c55..3c09d95 100644
--- a/Chapters/Context.tex
+++ b/Chapters/Context.tex
@@ -20,8 +20,6 @@
   language (you can't use case statements in Lava, since they would be
   executed only once during circuit generation) and extra notational overhead.
 
-\fxnote{There should be a section on DSLs here}
-
   We will now have a look at the existing hardware description languages,
   both conventional and functional to see the fields in which Cλash is
   operating.
@@ -45,7 +43,40 @@
       simplify program verification.
     \stopitemize
   
-  \section{Existing functional hardware description languages}
+    \placeintermezzo{}{
+      \defref{EDSL}
+      \startframedtext[width=8.5cm,background=box,frame=no]
+      \startalignment[center]
+        {\tfa Embedded domain-specific languages (\small{EDSL})}
+      \stopalignment
+      \blank[medium]
+     
+      \startcitedquotation[hudak96]
+      A domain-specific language (\small{DSL}) is a program-
+      ming language or executable specification language
+      that offers, through appropriate notations and ab-
+      stractions, expressive power focused on, and usu-
+      ally restricted to, a particular problem domain.
+      \stopcitedquotation
+
+      \todo{ref: http://portal.acm.org/citation.cfm?id=352035\&dl=}
+      
+      An embedded \small{DSL} is a \small{DSL} that is embedded in
+      another language. Haskell is commonly used to embed \small{DSL}s
+      in, which typically means a number of Haskell functions and types
+      are made available that can be called to construct a large value
+      of some domain-specific datatype (\eg, a circuit datatype). This
+      generated datatype can then be processed further by the
+      \small{EDSL} \quote{compiler} (which runs in the same environment
+      as the \small{EDSL} itself. The embedded language is then a, mostly
+      applicative, subset of Haskell where the library functions are the
+      primitives. Sometimes advanced haskell features such as
+      polymorphism, higher order values or type classes can be used in
+      the embedded language.
+      \stopframedtext
+    }
+
+  \section[sec:context:fhdls]{Existing functional hardware description languages}
     As noted above, we're not the first to walk this path. However, current
     embedded functional hardware description languages (in particular those
     using Haskell) are limited by:\todo{Separate TH and EDSL approaches
diff --git a/Utils/Lambda.tex b/Utils/Lambda.tex
index 319b424..f88dfb4 100644
--- a/Utils/Lambda.tex
+++ b/Utils/Lambda.tex
@@ -138,4 +138,17 @@ draw b;
 \setupcaption[intermezzo][location=top,number=no] % Put captions on top
 
 \setupheads[aligntitle=float]
+
+% A variant of \startquotation that puts a citation directly after the
+% quote.
+\long\def\startcitedquotation[#1]#2\stopcitedquotation
+    {\bgroup \par
+     \startnarrower
+       \symbol[leftquotation]%
+       #2\removeunwantedspaces
+       \symbol[rightquotation]%
+       \mbox{ }\cite[#1]
+     \stopnarrower
+     \par \egroup}
+
 % vim: set sw=2 sts=2 expandtab:
-- 
2.30.2