Andreas Prell aprell

Approachable PL Papers for Undergrads

On September 28, 2021, I asked on Twitter:

PL Twitter:

you get to recommend one published PL paper for an undergrad to read with oversight by someone experienced. the paper should be interesting, approachable, and (mostly) self-contained.

what paper do you recommend?

This project is a tiny compiler for a very simple language consisting of boolean expression.

The language has two constants: 1 for true and 0 for false, and 4 logic gates: ! (not), & (and), | (or), and ^ (xor).

It can also use parentheses to manage priorities.

Here is its grammar in BNF format:

expr ::= "0" | "1"

Program Analysis Resources

(draft; work in progress)

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

	/*
	Compile with one of the following:
	zig cc -v -s -Os -target aarch64-linux-musl -nostdlib -flto -static shell.c -o csh
	zig cc -v -s -Os -target aarch64-linux-gnu -nostdlib -flto -static shell.c -o csh

	CLANG:
	clang -v -s -Oz -ffreestanding -nostdlib -fno-stack-protector -Wl,--entry=_start -Wl,--gc-sections -Wl,-z,now -flto -static -o csh shell.c
	musl-clang -v -s -Os -nostdlib -nostartfiles -fno-stack-protector -Wl,--entry=_start -Wl,--gc-sections -Wl,-z,now -flto -nostdinc -static -o csh shell.c

	GCC (some things DO NOT WORK like `pwd`):

	let discard _a b = b

	let rec pp lvl = function
	\| `Lam f -> "(λ" ^ pp (lvl + 1) (f (`Go lvl)) ^ ")"
	\| `Pi (a, f) -> "(Π" ^ pp lvl a ^ "." ^ pp (lvl + 1) (f (`Go lvl)) ^ ")"
	\| `Appl (m, n) -> "(" ^ pp lvl m ^ " " ^ pp lvl n ^ ")"
	\| `Ann (m, a) -> "(" ^ pp lvl m ^ " : " ^ pp lvl a ^ ")"
	\| `Go x -> string_of_int x
	\| `Star -> "*"
	\| `Box -> "☐"

	module C : sig
	type t
	val empty : t
	val one : char -> t
	val union : t -> t -> t
	val inter : t -> t -> t
	val top : t
	val mem : char -> t -> bool
	val make : (char -> bool) -> t
	val equal : t -> t -> bool

	type term =
	\| Lam of (term -> term)
	\| Pi of term * (term -> term)
	\| Appl of term * term
	\| Ann of term * term
	\| FreeVar of int
	\| Star
	\| Box

	let unfurl lvl f = f (FreeVar lvl)

	// Tails has grown a bit and moved out into its own repository: https://github.com/snej/tails/
	// Please visit it there!
	//
	// If you want to see the tiny original version from May Forth 2021, it's still here;
	// click the "Revisions" button above, or go to:
	// https://gist.github.com/snej/9ba59d90689843b22dc5be2730ef0d49/2d55f844b7622aa117b9275bbc9d189613f7ff7f

	# This isn't supposed to run as a bash script, i named it with ".sh" for syntax highlighting.

	# https://developer.nvidia.com/nsight-systems
	# https://docs.nvidia.com/nsight-systems/profiling/index.html

	# My preferred nsys (command line executable used to create profiles) commands
	#
	# In your script, write
	# torch.cuda.nvtx.range_push("region name")
	# ...