Wednesday, February 10, 2021

Show HN: A 'cable scrambler' for live streaming video https://ift.tt/3q7yz8g

Show HN: A 'cable scrambler' for live streaming video https://ift.tt/3qJyNT2 February 10, 2021 at 11:03PM

Show HN: I've built a Python and FastAPI project to mock APIs during development https://ift.tt/3rFDYUn

Show HN: I've built a Python and FastAPI project to mock APIs during development https://ift.tt/3rED4HR February 10, 2021 at 10:51PM

Launch HN: Wasp (YC W21) – DSL for building full-stack web apps https://ift.tt/3qaJXQK

Launch HN: Wasp (YC W21) – DSL for building full-stack web apps Hi HN! We are Martin and Matija, twin brothers and creators of Wasp ( https://wasp-lang.dev ). Wasp is a declarative language that makes it really easy to build full-stack web apps while still using the latest technologies such as React, Node.js and Prisma. Martin and I both studied computer science where we mostly focused on algorithms for bioinformatics. Afterwards we led engineering teams in several SaaS companies, on the way gaining plenty of experience in building web apps. Moving from one project to another, we used various technologies: JQuery -> Backbone -> Angular -> React, own scripts / makefile -> Grunt -> Gulp -> Webpack, PHP -> Java -> Node.js, … , and we always felt that things are harder than they should be. We were spending a lot of time adopting the latest tech stack and figuring out the best practices: how to make the web app performant, scalable, economical and secure and also how to connect all the pieces of the stack together. While the tech stack kept advancing rapidly, the core requirements of the apps we were building changed very little (auth, routing, data model CRUD, ACL, …). That is why about 1.5 years ago we started thinking about separating web app specification (what it should do) from its implementation (how it should do it). This led us to the idea of extracting common web app features and concepts into a special specification language from which we could generate code in the currently popular technologies. We don’t think it is feasible to replace everything with a single language so that is why we went with a DSL which integrates with the modern stack (right now React, NodeJS, Prisma). Wasp lets you define high-level aspects of your web app (auth, routing, ACL, data models, CRUD) via a simple specification language and then write your specific logic in React and Node.js. The majority of the code is still being written in React and Node.js, with Wasp serving as the backbone of your whole application. To see some examples of what the language looks like in practice, take a look here: https://ift.tt/3jD007v... The main difference between Wasp and frameworks (e.g. Meteor, Blitz, Redwood) is that Wasp is a language, not a library. One benefit of that is a simpler and cleaner, declarative syntax, focused on the requirements and detached from the implementation details. Another benefit of a DSL is that it allows Wasp to understand the web app’s requirements during the build time and reason about it before generating the final code. For example, when generating code to be deployed to production, it could pick the most appropriate architecture based on its understanding of the web app and deploy it to serverless or another type of architecture (or even a combination). Another example would be reusing your data model logic through all the parts of the stack while defining it just once in Wasp. DSL opens the potential for optimisations, static analysis and extensibility. Wasp’s compiler is built in Haskell and it compiles the source code in Wasp + React/Node.js into the target code in just React and Node.js (currently in Javascript, but we plan to move to Typescript soon). The generated code is human readable and can easily be inspected and even ejected if Wasp becomes too limiting. We are currently in Alpha and many features are still rough or missing, but you can try it out and build and deploy web apps! There are things we haven’t solved yet and others that will probably change as we progress. You can check out our repo at https://ift.tt/2SIi9DY and give it a try at https://ift.tt/370R06Z . Thank you for reading! We would love to get your feedback and also hear about your experiences building web apps - what has worked for you and where do you see the opportunities for improvement? February 10, 2021 at 10:45PM

Speed and Turn Limits to Boost Safety on Tenderloin Streets

Speed and Turn Limits to Boost Safety on Tenderloin Streets
By Benjamin Barnett

The SFMTA is undertaking two new traffic safety improvements as a part of our Tenderloin Traffic Safety project: (1) prohibiting vehicle turns on red at approximately 54 intersections and (2) reducing vehicle speed limits to 20 miles per hour on 17 corridors.

Map showing speed limit reduction to 20mph neighborhood-wide between: Grove Street (south), Sutter Street (north), Mason Street (east), and Van Ness (West). Showing no turn on red regulations neighborhood-wide inclusive of Grove Street (south), Sutter Street (north), Mason Street (east), and Polk Street (west)

(Accessible Engineering details)

Map identifying all Tenderloin corridors and intersections where 20 mph speed limits and No Turn on Red will be implemented.

The Tenderloin is home to many of our most vulnerable communities including historically marginalized groups such as people with disabilities, communities with limited-English proficiency and those living in single-room occupancy hotels (SROs) and supportive housing. At the same time, every single street in the Tenderloin is a part of the city’s High Injury Network -- the 13 percent of San Francisco streets that account for 75 percent of severe traffic injury collision and fatalities. The gravity of the situation in the Tenderloin means we cannot delay taking actions that will improve safety for everyone in this critical neighborhood.

No Turn On Red

Photo of no turn on red sign at intersection of Golden Gate and Jones

Prohibiting turns while facing a red traffic signal is a proven method for reducing intersection conflicts. This includes both right turns and legal left turns from one one-way street to another. We will be piloting this new program at approximately 54 intersections in the Tenderloin. The program doesn’t include intersections that already have an existing turn prohibition, pedestrian scramble or are not signalized.

Turning on red may be the norm in many driving situations, but should not be on bustling Tenderloin streets. In a study conducted by Department of Public Health and SFMTA of crashes at signalized intersections, turns on red accounted for nearly 20% of turn-related crashes. These were largely clustered in the Tenderloin.

Heavy vehicular traffic in the Tenderloin provides little opportunity for drivers to safely make the turn on red, which leads to vehicles blocking crosswalks while drivers look left trying to find a gap in oncoming traffic. Drivers quickly executing their turn may fail to see a pedestrian legally crossing from the right which can result in an injury collision.

The legislative process for the No Turn on Red program will start in early 2021, with an expected Spring 2021 rollout. No Turn on Red signs will be posted on signal mast arms and poles notifying motorists of the prohibition.

20 mph Speed Limits

Another innovative approach we are taking to make the Tenderloin a safer place for pedestrians is lowering the speed limit from 25 mph to 20 mph. We will put this limit into effect on every corridor in the neighborhood. Vehicle speed is the number one predictor of crash severity. A pedestrian struck at 20 mph versus 25 mph has double the chance of survival. Lowering speed limits to better reflect conditions in the Tenderloin will provide tangible safety benefits in advance of any future engineering changes that can be made. For example, a recent study from Seattle, Washington demonstrated that posting new, lower limits led to reductions in speeds and collisions, even in the absence of streetscape or enforcement changes.

Learn More

For more details, please visit our project page, where you can also read about the community partners who were vital in planning these improvements.

 



Published February 10, 2021 at 10:14PM
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Show HN: Using ML to highlight unusual parts of S-1s for IPOs https://ift.tt/3rGMu5O

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Show HN: HN Comment Saver – best tool to save and manage your favorite comments https://ift.tt/3tOj0F0

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