Skip to main content

elizabeth wei's blog

Search This Blog

Firebase Presentation

on September 20, 2016

Get link
Facebook
Twitter
Pinterest
Email
Other Apps

Posting the slides from my presentation about Firebase to the Haystack Group here!

Get link
Facebook
Twitter
Pinterest
Email
Other Apps

Popular Posts

Building A Toy Language Interpreter in Go

In this post, I'll be giving a high-level overview of interpreters, why they're interesting, and how they work. I'll be referencing my repo, go_interpreter, which is a simple interpreter written in Go for a toy language. The figure below shows the structure of our interpreter with an example input:
What is an interpreter? An interpreter is a language processor that seems to directly execute the source program on user input:
In contrast, a compiler first takes in a source program and translates it to an executable machine code target program. Then, the user can pass in inputs to this target program and get outputs.
In general, an interpreter is better at reporting errors since it's processing statements one at a time, and a compiler is faster at generating outputs from inputs.

In this post, we're going to go over a simple interpreter that is capable of supporting:
integers, booleans, strings, arrays, hashmapsprefix, infix operatorsindex operatorsconditionalsglobal a…

tldr: Concurrency Control & Recovery

Part of the tldr series, which summarizes papers I'm currently reading. Inspired by the morning paper.
tldr: Concurrency Control & RecoveryFranklin

Concurrency control makes sure that users see consistent states of the database even though users' operations may be concurrent. Recovery makes sure that software or hardware failures don't corrupt the database state. Together, these DBMS components make things easier for developers who create applications on top of a database.
Transactions A transaction groups a set of logical operations into a unit, that all abort or all commit as one. If a transaction commits, all its updates become permanent and visible to other transactions. If a transaction aborts, all its updates are erased. The properties that a transaction should have are:
Atomicity: all or none of the operations in a transaction succeed.Consistency: the transaction leaves the database in a consistent* state. *A circular definition, but consistent means that the data…

board2board

This winter break, Andrew (my brother) and I worked on board2board, a collaborative drawing web app that uses a computer's webcam for object detection. We were inspired to create this after realizing that at least on our Macs, it was annoying to draw on the trackpad or having to switch back and forth to our iPads. Why not draw in the air instead?

Features include using the space bar to toggle between drawing/not drawing...

...pressing the "c" key to clear everything...
...multiple users collaborating in the same session (hover over avatars to see full usernames)...

...and being able to choose between detecting green or blue drawing objects. For example, in the gif below, using a green marker is much more accurate. We added this feature after finding that object detection accuracy heavily depends on where the user is. If there's a lot of other blue, then a blue marker wouldn't be as easily tracked.

Check out my brother's blog post for more details, including…

Powered by Blogger

Theme images by A330Pilot