Tag Archives: computer language

Iteration versus Recursion

19 Monday Dec 2016

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When it comes to what makes a computer (or any other) language a programming language, there are three characteristics usually required:

  1. Saving state (variables)
  2. Selecting a code path (if-then)
  3. Iteration or recursion (or equivalent)

This post is just a brief note (for a friend) about the third item and why it allows three distinct options.

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LPL-1

23 Friday Oct 2015

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Here’s the last of the oddball Little Programming Languages (for now). This one is a little like LPL-2 in using a three-part syntax (which turns out to be non-ideal). Unlike LPL-3, neither of these are particularly usable languages — more along the lines of being something a language designer amused himself with on a rainy afternoon.

A key goal in LPL-1 was to minimize the use of punctuation characters. No brackets or parenthesis to create syntax blocks. (Square brackets for array indexing and parentheses for expressions, but that’s it.)

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LPL-2

19 Monday Oct 2015

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The language I showed you last time, in LPL-3, was a fairly reasonable one. This time I’m showing you a preposterous one no one would actually use. Worse, it turns out to be something of a failure due to weird holes left by the design goal of orthogonal single-syntax construction.

But that oddness helps us focus on what a programming language actually is, so it’s worth a peek. And maybe it’ll give you a laugh.

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LPL-3

12 Monday Oct 2015

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I’ll pick up with the language I began describing last time in a future post. Right now I want to pick up the thread of Little Programming Languages (LPLs) and use several examples to illustrate what underlies a programming language. (And as it turns out, these are “little” only in a certain sense.)

This first example, LPL-3, is Lisp-like and, because of that, is fairly orthogonal. Even better, it’s probably actually usable, although — like Lisp — it doesn’t have the cleanest syntax (languages like Python have really spoiled me).

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Little Programming Languages

06 Tuesday Oct 2015

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One characteristic of the hard-core coder is a love of computer languages, programming languages in particular. Programmers of that ilk — of my ilk — collect new languages like merit badges. (I get a kick out of saying that I’ve programmed “from Ada to the Z-80!”)

The especially far gone of us also enjoy creating new languages (or in some cases, new dialects of XML). Lately I’ve been playing with a language design that follows a favorite theme: the single-syntax construction language.

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HTML is not a programming language!

22 Monday Dec 2014

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A webpage is a text document written in HTML. This document may also contain CSS and/or JavaScript, but it’s basically an HTML text document. You could write one — including the CSS and JavaScript — using just a pencil and paper.

Despite not needing a computer to write, all three are computer languages — they are languages used by, understood by, computers (and trained humans). However only one of those (JavaScript) is a programming language.

This is a brief explanation of which is which and why.

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