From e08923dadcbd9a1fc17aab44b57fc308dc9734be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Hillerstr=C3=B6m?= <daniel.hillerstrom@ed.ac.uk>
Date: Wed, 7 Oct 2020 21:16:22 +0100
Subject: [PATCH] Note on dynamic binding.

---
 thesis.bib | 40 ++++++++++++++--------------------------
 thesis.tex | 42 +++++++++++++++++++++++++++---------------
 2 files changed, 41 insertions(+), 41 deletions(-)

diff --git a/thesis.bib b/thesis.bib
index 24a03cf..d56ffdd 100644
--- a/thesis.bib
+++ b/thesis.bib
@@ -460,30 +460,6 @@
   year      = {2008}
 }
 
-# WebAssembly
-@misc{HaasRSTGWBH17,
-  author = {Andreas Haas and Andreas Rossberg and Ben L. Titzer and Dan Gohman and Luke Wagner and JF Bastien and Michael Holman},
-  title  = {Bringing the {Web} up to Speed with {WebAssembly}},
-  year   = 2017,
-  note   = {Draft},
-  howpublished = {\url{https://people.mpi-sws.org/~rossberg/papers/Haas, Rossberg, Schuff, Titzer, Gohman, Wagner, Bastien, Holman - Bringing the Web up to Speed with WebAssembly [Draft].pdf}}
-}
-
-# ECMAScript
-@misc{EMCA15,
-  author = {{Ecma International}},
-  title  = {{ECMAScript} 2015 Language Specification},
-  year = 2015,
-  url = {http://www.ecma-international.org/ecma-262/6.0/index.html}
-}
-
-@misc{EMCA17,
-  author = {{Emca International}},
-  title  = {{ECMAScript} 2017 Language Specification},
-  year = 2017,
-  url = {https://tc39.github.io/ecma262/}
-}
-
 # Hop.js
 @inproceedings{SerranoP16,
   author    = {Manuel Serrano and
@@ -646,7 +622,19 @@
   howpublished = {{ML Workshop}}
 }
 
-% fancy row typing systems that support shapes
+# Delimited Control
+@inproceedings{KiselyovSS06,
+  author    = {Oleg Kiselyov and
+               Chung{-}chieh Shan and
+               Amr Sabry},
+  title     = {Delimited dynamic binding},
+  booktitle = {{ICFP}},
+  pages     = {26--37},
+  publisher = {{ACM}},
+  year      = {2006}
+}
+
+# fancy row typing systems that support shapes
 @inproceedings{BerthomieuS95,
   author = {Bernard Berthomieu and Camille le Moniès de Sagazan},
   title = {A Calculus of Tagged Types, with applications to process languages},
@@ -663,7 +651,7 @@
 }
 
 
-
+# Zipper data structure.
 @article{Huet97,
   author    = {G{\'{e}}rard P. Huet},
   title     = {The Zipper},
diff --git a/thesis.tex b/thesis.tex
index 311d941..865f534 100644
--- a/thesis.tex
+++ b/thesis.tex
@@ -22,11 +22,11 @@
 \DeclareCaptionFormat{underlinedfigure}{#1#2#3\hrulefill}
 \captionsetup[figure]{format=underlinedfigure}
 \usepackage[T1]{fontenc}      % Fixes issues with accented characters
-\usepackage[scaled=0.85]{beramono}
 %\usepackage{libertine}
 %\usepackage{lmodern}
 %\usepackage{palatino}
 % \usepackage{newpxtext,newpxmath}
+\usepackage[scaled=0.85]{beramono}
 \usepackage[activate=true,
     final,
     tracking=true,
@@ -2204,24 +2204,36 @@ The (delimited) continuation of $\exit~1$ is effectively dead code.
 \subsection{Dynamic binding: user-specific environments}
 \label{sec:tiny-unix-env}
 
-In \UNIX{} an environment maps keys to string-values. A key-value pair is
-referred to as an \emph{environment variable}. Each user gets their
-own environment with their own set of environment variables. Some
-environment variable names are common to all environments, but their
-valuation may depend on the particular user session. For example, the
-environment variable \texttt{USER} is bound to the (string) name of
-the user; the result of querying the environment for the value of
-\texttt{USER} depends on which user session it is executed under.
+When a process is run in \UNIX{}, the operating system makes available
+to the process a collection of name-value pairs called the
+\emph{environment}.
+%
+The name of a name-value pair is known as an \emph{environment
+  variable}.
+%
+During execution the process may perform a system call to ask the
+operating system for the value of some environment variable.
+%
+The value of environment variables may change throughout process
+execution, moreover, the value of some environment variables may vary
+according to which user asks the environment.
 %
-\dhil{The value of an environment variable may also change during execution.}
+For example, an environment may contain the environment variable
+\texttt{USER} that is bound to the name of the inquiring user.
 
-An environment variable is an instance of dynamic binding. The idea of
-dynamic binding as a programming notion dates back as far as the
-original implementation of Lisp~\cite{McCarthy60}.
+An environment variable can be viewed as an instance of dynamic
+binding. The idea of dynamic binding as a binding form in programming
+dates back as far as the original implementation of
+Lisp~\cite{McCarthy60}, and still finds uses in successors such as
+Emacs Lisp~\cite{LewisLSG20}. It is well-known that dynamic binding
+can be encoded as a computational effect by using delimited
+control~\cite{KiselyovSS06}.
 %
-We will use dynamic binding to implement user-specific environments.
+Unsurprisingly, we will use this insight to simulate user-specific
+environments using effect handlers.
 
-For simplicity we will fix the users to be root, Alice, and Bob.
+For simplicity we fix the users of the operating system to be root,
+Alice, and Bob.
 %
 \[
   \User \defas [\Alice;\Bob;\Root]