Wednesday, February 18, 2009

PLT System Facilities (Software Components): Lexical scope

Like any programming system, PLT Scheme involves multiple people and a lot of code. So managing software components is a primary concern. And of course, as a Scheme, PLT uses lexical scope as the linguistic linchpin for managing software. The importance of lexical scope in a component architecture is that it allows code to be shared and mixed while guaranteeing the internal integrity of components.

With the power of macros, PLT has developed a number of software component abstractions on top of little lambda. One of these is a single-inheritance, class- and interface-based OOP system. Classes are first-class values, which means it's easy to implement mixins (i.e., classes parameterized over their superclass) as functions that return classes. More recently, they've introduced traits, which are like fragments of classes that can be more freely and flexibly combined than mixins. Also built with macros is the unit system, which is a first-class, parameterized, recursive module system.

All of these abstractions admit modular and separate development because they protect the internal integrity of their local bindings and definitions. You can hand out a component into an untrusted context and know that it won't be able to modify or even inspect the component's internals. And you can reason locally about your code knowing that no context can change its behavior based on these internals.

33 comments:

Sam Tobin-Hochstadt said...

I love the turtles.

vijay said...




192.168.0.1

192.168.l0.1 Router login

https://www-1921681254.com This IP address is used by the routers like TP-Link, Netgear, D-Link uses it as the default IP address.

DRD Digital Marketing said...

DRD Digital Marketing will Get unreal traffic to your site and rank one in Google, starting at about 100 real people with personal ip addresses per day. Options to increase and extend the time duration are available to suit your needs

Daily Medicos said...

Medical informatics has influence over a lot of medi care aspects over the years. Do you call a pharmacist doctor means that Pharmacist and Doctor both are similar in that way, pharmacist are defined as trained personnel or pharmacy technicians who are purposefully trained to enable them to handle the medication errors & to promote patient safety more efficiently. Here you explore how long does a stye last and everything.

Anonymous said...

Hello! If you want to hire female private investigator, then go and explore this website. Here at Integral Investigations, we take great pride in offering personalized services to our customers.

Anonymous said...

Hello! If you want to hire female private investigator, then go and explore this website. Here at Integral Investigations, we take great pride in offering personalized services to our customers.

Anonymous said...

Welcome to Lipstick Investigations, Australia’s highest profile relationships private detective and private investigator wollongong. We have relocated our private investigators office into the Sydney CBD after having an office in North Sydney just over the Harbour Bridge since 1997.

Anonymous said...

Abdulla Thani group of technical services offers the following services to its clients with respect to interior designing, Construction administration, Documentation, Space planning, Procurement and installation, Furniture accessory and Wall painting, tile fixing company in Dubai.

Vantage said...

Enhance your CCTV system with web access. By accessing your CCTV system from the internet, you can get a piece of mind you are looking for. Ask Vantage security systems about their great prices on web enabled security camera.

Miami Laundry said...

Miami Laundry Service
is workable customized services that stand as same as factory-based laundry services. We ensure to take bold steps in cleaning services to wash away the worries of the community.

Utubster said...

Download UTUBSTER, The free YouTube Converter and Downloader that just works! It’s features include download playlists, videos and YouTube to MP3 from major websites like never before.

Nevada Mortgage Services said...

Vision Home Mortgage goal is to provide home loans to our clients while providing them with the lowest interest rates and closing costs possible. We offer our clients a more personal touch. You have one experienced loan officer who you can contact directly, and is also there every step of the way.

Primary Projects said...

Welcome to Primary Projects, A good basis ensures a healthy balance between private and work. We make sure that you enjoy going to work and can carry out your assignment with a smile. Here you may find plastering work, Demolition and Clearance Service, Residential and utility construction.

Anonymous said...

Welcome to Primary Projects, A good basis ensures a healthy balance between private and work. We make sure that you enjoy going to work and can carry out your assignment with a smile. Here you may find plastering work, Demolition and Electrical and Installation Technology and Clearance Service.

vijay said...

192.168.10.1

192.168.1.0

192.168.l.254

192.168.l.1

192.168.100.1

192.168.15.1

192.168.8.1

Daily Medicos said...

Welcome to Daily Medicos, Stye is a painful lump or ball-like structure present outside or inside the eyes that causes pain and itching. It is full of pus and looks like an acne and pimple type. However, the appearance of a stye can be unsightly at times. If you want to know about number one pharmacy school, then go and explopre their website.
Thank you.

Plenty Thingz said...

Deze Convectorradiator, opgebouwd uit 2 panelen en 2 convectors, is ideaal voor het snel en effectief verwarmen van grotere leefruimtes. Dankzij het slanke ontwerp wordt onze radiator aan de muur bevestigd, wat een geweldige toevoeging is aan kleinere ruimtes zoals gangen en hallen.

Unknown said...

PEACE GANG the brand started out as myself just wanting to wear unique streetwear/hip hop style clothing that was centered around something POSITIVE and not "materialistic" or "trendy". The meaning behind the name PEACE GANG simply means a group of people "gang" focused on bettering the planet they live on. Our tagline R U DOWN? means " R U DOWN with doing your part to make the world a better place"? If you’re searching positive sustainable urban streetwear then go and checkout their website.

Unknown said...

The best home solar panels power electricity system largely depends on the location of your homes, offices etc. Now that you know the differences between the systems, you can determine which is the best home solar panels system—where you live will play a significant role in this decision.

MCMK B2B Tech Marketing Solution said...

If you want to know about Website Development Strategy then first check out all these strategies. From determining your company's value proposition, brand messaging, target audience, buyer profiles and more, we help tech companies develop and execute winning marketing strategies. ABM, events, email marketing, content syndication, and more. An effective demand generation campaign will help you build awareness, generate a healthy pipeline of leads, and grow revenue.

Unknown said...

Energenic Solar Energy Australia has been at the forefront of the solar industry in Sydney, Australia. Now, we are providing our services through an online platform. Our sales team is backed by our experienced, long-standing engineering team and in-home solar panels manufacturing and servicing facilities.

Anonymous said...

Energenic Solar, the best commercial solar panel system believes in making going green as easy as possible to convert your electricity supply from energy to a solar system. We offer the best solar power system multiple plans to fit your needs, including installation, buy a cheap and best solar power system for homes, companies, and factories.

Jhonxxx said...

The institute of best holistic courses, Natura, creates a safe and friendly way of learning, to embrace healing modalities in a natural and supported way, it can be a scary journey, but exciting at the same time when you embark on a new life path.

Bipard said...

I hope to see more post from you. Thank you for sharing this post. Your blog posts are more interesting and impressive

Avsar App, Haryana Avsar App Download, Assessment/Exam Online 2021

Yakshita said...

Your blog is filled with unique good articles! I was impressed how well you express your thoughts.

djb water bill 2021 | djb water bill online payment | Delhi Jal Board Water Bill 2021

Primary Projects said...

Welkom bij Primary Projects, Een goede basis zorgt voor een gezonde balans tussen privé en werk. Wij zorgen ervoor dat je met plezier naar je werk gaat en je opdracht met een glimlach kunt uitvoeren. Hier vindt u onder andere stukadoorswerk, Systeemplafonds en wanden.

Plenty Thingz said...

Plenty Thingz is een e-commerce website, hier kun je elk product vinden. Spin, wiebel en race; het kan allemaal met onze kinderauto! Deze wiebelende auto houdt je kind actief en ontwikkelt zijn evenwichts- en coördinatievaardigheden tijdens het spelen. Hier vindt u voedertafels voor vogels.

vijay said...
This comment has been removed by the author.
vijay said...


This configuration can also be used for devices like Router, Modem etc. and they are all having the initial IP address

192.168.l0.1

192.168.0.1

Anonymous said...

Help your business grow by equipping yourself with the most powerful href="https://ciserp.com/" ERP Software in Pakistan
that provides you full control and better management over your business. Intelligently aid your business to boost towards success with better decision making

Smart Home Guider said...

WYA tv Roku devices also support screen mirroring features. Users use this feature to watch the content they don’t have on their Roku device like some apps that are not available on the Roku channel store.

Cisepos Express said...

A POS software karachi online demo can be a valuable resource for businesses looking to implement a new point-of-sale system.

Muqqabla Local Shopping said...

Muqqabla provides the Best deals in Bangalore