dhil/phd-dissertation
1
0
Fork 0
mirror of https://github.com/dhil/phd-dissertation synced 2026-03-13 11:08:25 +00:00
Code Issues Releases Wiki Activity

Section 2.3

Browse Source
This commit is contained in:
Daniel Hillerström
2021-12-17 17:57:31 +00:00
parent 6492391ed4
commit 98784c59ab
1 changed files with 8 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
thesis.tex
View File

@@ -3094,8 +3094,12 @@ The following handler implements the environment.
The handler takes as input the current $user$ and a computation that The handler takes as input the current $user$ and a computation that
may perform the $\Ask$ operation. When an invocation of $\Ask$ occurs may perform the $\Ask$ operation. When an invocation of $\Ask$ occurs
the handler pattern matches on the $user$ parameter and resumes with a the handler pattern matches on the $user$ parameter and resumes with a
string representation of the user. With this implementation we can string representation of the user. This handler is an instance of a
interpret an application of $\whoami$. so-called \emph{tail-resumptive} handler~\cite{Leijen17b,XieBHSL20} as
each resumption invocation appears in tail position within in the
operation clause.
%
With this implementation we can interpret an application of $\whoami$.
% %
\[ \[
\environment~\Record{\Root;\whoami} \reducesto^+ \strlit{root} : \String \environment~\Record{\Root;\whoami} \reducesto^+ \strlit{root} : \String
@@ -3105,8 +3109,8 @@ It is not difficult to extend this basic environment model to support
an arbitrary number of variables. This can be done by parameterising an arbitrary number of variables. This can be done by parameterising
the $\Ask$ operation by some name representation (e.g. a string), the $\Ask$ operation by some name representation (e.g. a string),
which the environment handler can use to index into a list of string which the environment handler can use to index into a list of string
values. In case the name is unbound the environment, the handler can values. In case the name is not bound in the environment, the handler
embrace the laissez-faire attitude of \UNIX{} and resume with the can embrace the laissez-faire attitude of \UNIX{} and resume with the
empty string. empty string.
\paragraph{User session management} \paragraph{User session management}