1. 11/16/2018
The PL Part of CS Dan Grossman Department of Computer Science & Engineering University of Washington SPLASH-E October 28, 2013

2. Before we dive in…
History in 1 line: CS2001 generally reviled by the PL community
Much work by others to lay groundwork to “fix it”
If you don’t like CS2013, it’s my fault 
Don’t fret over “what is PL” in “Body of Knowledge”
“PL” includes lots of “programming” and all of “compilers and run-time systems”…
That’s “good” if selfish about the writing
Less “good” if selfish about the hours
But the steering committee was thankfully not selfish
Experts will never be happy 
Imagine a department with 5 CS faculty, none in PL
Curriculum must be implementable and [only] a bit forward-looking
October 28, 2013
Grossman: PL in CS2013

3. Acknoweldgements, part 1
Started early with a diverse committee of reasonable size
Result much better than I could have done alone
Kim Bruce
Curt Clifton
Ernesto Cuadros-Vargas
Kathi Fisler
Kathleen Fisher
Stephen Freund
Matthew Hertz
Johan Jeuring
Doug Lea
Simon Thompson
October 28, 2013
Grossman: PL in CS2013

4. Acknowledgments, part 2
Then many fresh eyes to avoid (?) committee-speak
Guilt-trip s from me and public-comment periods
Alex Aiken
Ron Cytron
Tony Hosking
James Noble
Jens Palsberg
Benjamin Pierce
Michael Scott
Michelle Strout
Stephanie Weirich
Steve Zdancewic …
October 28, 2013
Grossman: PL in CS2013

5. High-level goals Language design, use, and semantics side:
Less OO-focused
Encapsulation not only a sub-topic of OOP
Benefits of avoiding side-effects, using closures
Modern parlance, understanding, and breadth
No “compiled vs. interpreted languages”
Rational arguments on static vs. dynamic typing
Language implementation side:
Program analysis for more than compiler optimization
Increasing importance/sophistication of run-time systems
Matter of principle + inclusiveness + timeliness:
No PL mentioned by name in Body of Knowledge
October 28, 2013
Grossman: PL in CS2013

6. Interactions All of OOP, FP, and Event-Driven is in PL
But recursion, decomposition, abstraction is in SDF
Because Body of Knowledge won’t “pick a paradigm for CS1”
Concurrency and parallelism mostly elsewhere (PD and SF)
Committee convinced me to add a PL unit for things like actors
Of course, PL touches in everything in computer science 
October 28, 2013
Grossman: PL in CS2013

7. The “core” pieces FP
First-class functions + lexically scoped environments
Mutation-free programming
OOP
As an abstraction mechanism
Subclassing
Event-driven
Program Representation: Code is data
“Basic Type Systems”: what they do [not] do
“Basic Translation Execution”: What a compiler/interpreter/run-time does, but not how to implement one
Key details like how recursion is implemented
October 28, 2013
Grossman: PL in CS2013

8. My one axe to grind Matrix of operations and data variants
Cf. “the expression problem”
Apologies if this came out “how Grossman teaches it”
eval
toString
hasZero …
Int
Add
Negate
October 28, 2013
Grossman: PL in CS2013

9. Elective != unimportant, part 1
Help modernize “the compilers course”
While acknowledging lexing/parsing still exists
Separate code generation from static analysis
New run-time system unit with GC, JITs, VMs
Mostly aspirational at this point??
Would love to discuss how to make this happen
October 28, 2013
Grossman: PL in CS2013

10. Elective != unimportant, part 2
“PL side” has units that justify foundational treatment…
Formal semantics, type systems, etc.
… and units that justify “advanced programming”…
Control operators, laziness, macros, mixins, …
Reflects a big-tent there-are-many-good-courses view
Now let’s fight over “better” with course exemplars and reusable materials
October 28, 2013
Grossman: PL in CS2013

11. In the end… SIGPLAN written SIGPLAN and broader community approved
Surely not perfect
Don’t ask the cook how the soup tastes 
How can we use this to best influence courses/curricula?
How can we best prepare the field for an even better curriculum in 2023?
Need to successfully connect advances to the classroom!
October 28, 2013
Grossman: PL in CS2013