Author: grant

How do you find the perfect programming language?

For many years I sought “the perfect programming language”. Traveling aim-fully from language to language, I found that there are a number of aspects to enjoy when it comes to a particular programming language, but I never found one that was “just right”.
During that journey, I started out as a slave to syntax. I had to “like” the syntax. Even when I found a syntax I liked, I would find that the language would be too narrowly-focused. Most general-purpose languages force you to shoe-horn your solution to a problem into how the language creator wants you to solve it. Most programmers hate being forced to do anything; especially how to think.
Eventually I realized that there is no “perfect programming language”. Perhaps, though, there is a language that is “good enough”.
A lot of folks love the programming language Lisp. It provides all of the core language features you could ever need. On top of that, it lets you tailor the syntax to your pleasure.
From what I know about Lisp, it is “good enough”, and in the world programming languages, that is probably just about the best compliment you could give any language.

Emacs influence on Ruby

Who would’ve thought that Ruby’s block ‘end’ keyword was created to facilitate Emacs? Oh man!

When [Matz] was first starting out writing Ruby, he was coding the Emacs ruby-mode.el for it at the same time. He expressed some frustration with modes for other languages like Python and Pascal in which the editor could not look at a line of code and figure out where it should be indented to, so he resolved that Ruby as a language should not fall into that particular trap. With that in mind he chose the end keyword as a block delimiter so that it would be easier to write an Emacs mode for.

Where to start with The Lambda Calculus

When you first start studying functional programming, one of the things that people will ask you is “So; have you learned lambda calculus (TLC)?”.
The fact is that while you don’t need to learn TLC to learn about functional programming; you ought too study the TLC at some point.
In this great LtU thread on “where to get started with studying programming language theory”, Anton van Straaten posted a comment referencing two posts on the PLT discussion list detailing a plan on what you should study when it comes to TLC and the texts that you should use to facilitate those studies.

Composing Functions with Scheme

In the PLT thread [‘complement'[?] of map] Stephen de Gabriel asked if there was a function that would take any number of functions, and an argument, and then apply the first function to the argument, and apply the second function to the result of the first, and so on.
In PLT Scheme, the function is called ‘compose’. Compose:

Returns a procedure that composes the given functions, applying the last f first and the first f last. The composed functions can consume and produce any number of values, as long as each function produces as many values as the preceding function consumes.

I asked if this was typical FP style, and Noel replied that it is so common that compose is an infix operation in Haskell and ML, as far as he could recall.
Here is an example (from the thread) of how it works using the “Pretty Big” language:

(define pam
  (lambda (datum . proc-list)
    ((apply compose proc-list) datum)))
(pam
 2
 (lambda (n) (/ n 7))
 (lambda (n) (- n 3))
 (lambda (n) (+ n 10))
 (lambda (n) (* n 7)))
> 3