Chaitanya Koparkar ckoparkar

Lightweight region memory management in a two-stage language

Intro
Basics
- Stage inference
Regions
- Bit-stealing
- Using regions
Eager regions

Flamegraphing in Rust can now be done with a new cargo subcommand. Please check this out before embarking on the legacy journey below: https://github.com/flamegraph-rs/flamegraph

flamegraphing rust binaries' cpu usage with perf

One-time setup

Install perf, using Brendan Gregg's guide: http://www.brendangregg.com/perf.html#Prerequisites
Install flamegraph from repo:

Profiling performance

Using perf:

$ perf record -g binary
$ perf script | stackcollapse-perf.pl | rust-unmangle | flamegraph.pl > flame.svg

NOTE: See @GabrielMajeri's comments below about the -g option.

Get Git log in JSON format

git log --pretty=format:'{%n  "commit": "%H",%n  "abbreviated_commit": "%h",%n  "tree": "%T",%n  "abbreviated_tree": "%t",%n  "parent": "%P",%n  "abbreviated_parent": "%p",%n  "refs": "%D",%n  "encoding": "%e",%n  "subject": "%s",%n  "sanitized_subject_line": "%f",%n  "body": "%b",%n  "commit_notes": "%N",%n  "verification_flag": "%G?",%n  "signer": "%GS",%n  "signer_key": "%GK",%n  "author": {%n    "name": "%aN",%n    "email": "%aE",%n    "date": "%aD"%n  },%n  "commiter": {%n    "name": "%cN",%n    "email": "%cE",%n    "date": "%cD"%n  }%n},'

The only information that aren't fetched are:

%B: raw body (unwrapped subject and body)
%GG: raw verification message from GPG for a signed commit

Simpler, Easier!

Lennart Augustsson, Oct 25, 2007

In a recent paper, Simply Easy! (An Implementation of a Dependently Typed Lambda Calculus), the authors argue that type checking a dependently typed language is easy. I agree whole-heartedly, it doesn't have to be difficult at all. But I don't think the paper presents the easiest way to do it. So here is my take on how to write a simple dependent type checker. (There's nothing new here, and the authors of the paper are undoubtedly familiar with all of it.)

First, the untyped lambda calculus.

I'll start by implementing the untyped lambda calculus. It's a very simple language with just three constructs: variables, applications, and lambda expressions, i.e.,

Simpler, Easier!

Lennart Augustsson, Oct 25, 2007

In a recent paper, Simply Easy! (An Implementation of a Dependently Typed Lambda Calculus), the authors argue that type checking a dependently typed language is easy. I agree whole-heartedly, it doesn't have to be difficult at all. But I don't think the paper presents the easiest way to do it. So here is my take on how to write a simple dependent type checker. (There's nothing new here, and the authors of the paper are undoubtedly familiar with all of it.)

First, the untyped lambda calculus.

I'll start by implementing the untyped lambda calculus. It's a very simple language with just three constructs: variables, applications, and lambda expressions, i.e.,

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

	module Main where

	import LLVM.AST
	import qualified LLVM.AST as AST
	import LLVM.AST.AddrSpace
	import qualified LLVM.AST.CallingConvention as CC
	import qualified LLVM.AST.Constant as C
	import LLVM.AST.Global
	import LLVM.AST.Linkage
	import LLVM.Context

	# Install tmux on Centos release 6.5

	# install deps
	yum install gcc kernel-devel make ncurses-devel

	# DOWNLOAD SOURCES FOR LIBEVENT AND MAKE AND INSTALL
	curl -OL https://github.com/downloads/libevent/libevent/libevent-2.0.21-stable.tar.gz
	tar -xvzf libevent-2.0.21-stable.tar.gz
	cd libevent-2.0.21-stable
	./configure --prefix=/usr/local

	(ns create-draw.opencv
	(:import
	org.opencv.core.Core
	org.opencv.core.Mat
	org.opencv.core.MatOfRect
	org.opencv.core.Point
	org.opencv.core.Rect
	org.opencv.core.Scalar
	org.opencv.highgui.Highgui
	org.opencv.objdetect.CascadeClassifier))