atlas des actus
Planet Lisp
25  juin     08h54
Paolo Amoroso: Adding an Exec command and File Browser support to Insphex
   I implemented the last features originally planned for Insphex, my hex dump tool in Common Lisp for Medley Interlisp. The first new feature is an Exec command for invoking the program. The command HD works the same way as the function INSPHEX:HEXDUMP and accepts the same arguments, a file name and...
24  juin     14h20
Joe Marshall: Embrace the Suck
   The key point here is our programmers are Googlers, they’re not researchers. They’re typically fairly young, fresh out of school, probably learned Java, maybe learned C or C, probably learned Python. They’re not capable of understanding a brilliant language but we want to use them to...
16  juin     19h19
Joe Marshall: Decode a Float (Solution)
   We can multiply or divide a floating point number by without changing the bits in the mantissa. So we can rescale the number to be in the range , by repeatedly multiplying or dividing by . The leftmost bit of the mantissa is always , but next bit determines whether the number is...
Joe Marshall: Decode a Float
   The leftmost bit of any positive binary number is always . So if you were to left justify a positive binary number, the top bit would always be . If the top bit is always, there is no need to implement it. Floating point numbers use this trick. You can determine the bits of an integer...
06  juin     11h23
Joe Marshall: D-day, 80 years ago today
   More than , troops,, ships, , aircraft in the largest amphibious assault in history.
05  juin     16h16
Joe Marshall: Multithreading and Immutable Data
   I was amusing myself by looking at Lisp tutorials. They used the idea of a Tic Tac Toe service as a motivating example. You’d be able to play Tic Tac Toe against the computer or another opponent. My immediate thought went to the issue of multithreading. If you were going to serve...
01  juin     14h54
Joe Marshall: Roll Your Own Syntax
   Unlike most languages, Lisp represents its programs as data structures. A Lisp program is a set of nested lists. We can look at a Lisp program as a tree, with each nested list as a node in the tree. The first element of each list indicates the kind of node it is. For instance, a sublist...
28  mai     14h27
Joe Marshall: If I Were in Charge
   If I were in charge of Python development, here are a few things I would do: Add optional tail recursion. This would make it easier to write pure functional code. It would also make it possible to effectively program in continuation passing style. Making tail recursion optional...
Paolo Amoroso: Building a GUI for Insphex
   I added a GUI to Insphex, the hex dump tool I’m writing in Common Lisp on the Medley Interlisp environment. The initial version printed the hex dump only to the standard output, now optionally to a separate TEdit window with a command menu. The menu has items for displaying the next page of output...
26  mai     22h27
Joe Marshall: Exception Handling for Control Flow
   Back when I was taking a Software Engineering course we used a language called CLU. CLU was an early object oriented language. A feature of CLU was that if you wrote your code correctly, the compiler could enforce completely opaque abstract data types. A good chunk of your grade depended...