NPRG075

Close look at past and today's programs

Tomáš Petříček, 309 (3rd floor)
petricek@d3s.mff.cuni.cz
https://tomasp.net | @tomaspetricek

Lectures: Monday 12:20, S7
https://d3s.mff.cuni.cz/teaching/nprg075

Close reading

Two perspectives

Two perspectives on programs

Critical code studies

Interpreting the meaning of code, software or systems
in socio-historical context

Attention to detail
Variable names

Making broad points
Labyrinths in culture

Complementary science

Use history & philosophy to answer questions science itself neglects

Attention to detail
How exactly did it work

Making those relevant
New mode of interaction


// Your first C++ program
#include <iostream>

int main()
{
  std::cout << "Hello World!\n";
  return 0;
}

Close reading

"Close reading is the careful, sustained interpretation of a brief passage of a text"

What can we learn?

Not always educational start (Java, Haskell)

Reference to a long-term hacker culture

Close reading

Programming language design

  • Understand socio-historical context
  • Design for better social & cultural use?
  • Understand lost ideas from the past
  • Recover and adapt what may be useful!

Critical code studies

Closer look at code

Hello World in Piet

Why look at esoteric languages?

We must not just observe nature in the raw, but also "twist the lion's tail" to get at hidden insights

May reveal facts about normal languages too!

The meaning of programs

>++++++++[<+++++++++>-]<
.>++++[<+++++++>-]<+.+++
++++..+++.>>++++++[<++++
+++>-]<++.------------.>
++++++[<+++++++++>-]<+.<
.+++.------.--------.>>>
++++[<++++++++>-]<+.

Speaking code

"Like all codes, [source code] is only interpretable within the context of the overall network of relations that make its operations unstable."

Meaning of code

  • Meaning for the machine
    Relies on technological context - compilers, specification
  • Meaning for a human reader
    Relies on socio-cultural context

Multiple levels of meaning

Mutual influences

Social shapes technical

Programming reflects our thinking about the world
e.g. division of labour

Technical shapes social

Abstractions define how we think about software
e.g. information hiding

Foo, bar, baz, ...

(Lennon, 2018)

Cultural pointer

Akin to programming language pointers

Marks work as belonging to a particular culture

Foo, bar, baz...

As cultural pointers

  • Metasyntactic variable / meaning placeholder
  • Variable names and comments are for humans
  • Neither \(x\) nor AbstractSingletonProxyFactoryBean
  • ARPANET and Request For Comments (RFCs)

Close look at UNIX 6

Process switching function

Close reading UNIX code

  • Variable names: i, n, p, rp
  • "set up his segmentation registers"
  • "You are not expected to understand this."

You are not expected to understand this

The real problem is that we didn't understand what was going on either.
The savu/retu mechanism (...) was fundamentally broken (...).

[It] worked on the PDP-11 because its compiler always used the same context-save mechanism (...). [Eventually we] redid the coroutine control-passing primitives altogether, and this code section,
and the comment, passed into history.

10 PRINT

Cultural context of
a BASIC one-liner

The birth of microcomputers and tinkerer culture

Randomness and variations of the pattern

Recreating the one-liner in other systems

Critical code studies

Ideas for programming

  • What socio-technical context design uses?
  • Design for hackers or non-programmers?
  • Analyse what exists, show what could exist
  • "Performative science fiction" demos

Thimbl: Performative science fiction

Federated social network (~2011)

  • Artwork, not to compete with Twitter
  • Built with a different social context
  • Can it work without investments?

How is it supposed to work?

  • Built with as little code as possible
  • Using SSH and Finger protocol (1970s)
  • Low-tech version of ActivityPub (Mastodon)

Programming system demos

Future programming

  • Imagining alternative ways
  • Often through (limited) demos
  • End-user, visual, domain-specific

Places to look at

Demo

Crosscut: Drawing Dynamic Models

Complementary science

Learning from the past

Complementary science

Contribute to scientific knowledge through historical and philosophical investigations

Effectiveness of science leads to dogmatism

Narrow focus can result in loss of knowledges

Heat reflection (1791)

Heat produced by "caloric", cold maybe by another "positive" substance.

Heat is reflected by mirror!
Cold is absence of heat?
But also reflected!

Modern physicists never talk about reflection of cold!

Complementary programming?

Dot-Com Design

(Ankerson, 2018)

Amateur can easily cobble something together

Hackability and familiarity of
graphical editors

Gives designers
full control

Complementary science

Why use it for programming

  • Feel all programming is the same?
  • Programming has brief but rich history
  • Not discarded for experimental failures
  • Ideas are (relatively) easy to recreate!

Demo

Annoying pop-ups of the 1990s

Learning from
the 1990s web

View-source, copy
and edit culture

Hosting on Geocities & creative community

Limited user protection (hacks are for fun)

Two eras of the web

2010s web

Compiled code
Minified with dependencies

Custom elements
Custom pop-ups using <div>

Opaque structure
WebAssembly & Canvas

1990s web

View source
Readable source code

Copy & paste
Self-contained scripts

Pop-up windows
Unchecked window.open

Learning from the 90s web

WebStrates project

  • Shareable dynamic media
  • Document and code in DOM
  • Synchronized across clients
  • In-page editor & dev tools

Further ideas

  • How to support reuse by copying?
  • Openness and addressability of DOM

Good old programming systems

Boxer's naive realism
You see all there is

Smalltalk's self-sustainability
Built in itself

Good old programming systems

Pygmalion's programming
By demonstration

Hypercard's usability
From user to programmer

Conclusions

Close look at programs

Close look

As evaluation
Reveals more than one may immediately see

As design tool
Think about programming from new perspectives

Reading

Are spreadsheets programming?

Why should you read this?

  • Interesting case of end-user programming
  • How to use programming ideas in new domains

Conclusions

Close reading and complementary science

  • Close look at fine coding details
  • Reveals broader cultural points
  • Close look at past programming systems
  • Reveals ideas we may have forgotten

Tomáš Petříček, 309 (3rd floor)
petricek@d3s.mff.cuni.cz
https://tomasp.net | @tomaspetricek
https://d3s.mff.cuni.cz/teaching/nprg075

References (1/2)

Critical code studies

Interesting past systems

References (2/2)

Complementary science & programming

History of UNIX

Programming demos