Wherefore Art, Thou?
Like many computer geeks, much of my artistic training has been in music. Of all the arts, it most clearly makes a programmer/interpreter distinction, so perhaps it's natural for a musician to think about how interpreters work. But the interpreters for a computer language are located both in the computer and in the human brain. I don't always know what makes a computer sad (or happy), but I do have a pretty good idea what makes a person mad (or sappy). Er, sorry.
Anyway, when I was young, I was taught that music has progressed through four major periods: Baroque, Classical, Romantic and Modern. (The other so-called fine arts have also gone through these periods, though not necessarily at the same rate.) I always thought it rather curious that we called the current period Modern, since definitionally the idea of modernity seems to be a permanently latched-on state, bound to the cursor of time, so to speak. But that was because the word “modern” still meant something back then. This was, after all, the 1960s. Who could have guessed that Modern period would be followed by the Post-Modern?
If you're willing to concede by now that the design of computer languages is an artistic medium of sorts (and searches), then it's reasonable for us to ask ourselves whether programming languages have been progressing through the same sequence of artistic development. Certainly, people have occasionally claimed that Perl is “baroque”, to which my usual retort is, “Thanks, I like Bach, too.” But this is merest rhetoric (on both sides).
So what do we really mean when we talk about these periods? Let's start at the beginning, which is the Baroque period. Of course, it's not really the beginning. People were producing music long before they ever invented the bucket in which to carry the tune. But before and during the Baroque period, there was tremendous technological progress in both the production and publication of music. Composers and performers could make a name for themselves. Innovators were rewarded, but the forms of expression were heavily influenced both by cultural expectations and by available hardware. People were expected to improvise. What we got was more or less the Cambrian explosion of music.
Similarly, at the dawn of the computer era, there were new opportunities to innovate. The geniuses of that period improvised many forms of assembly language. To them, these languages all looked very different. But nowadays we tend to see all assembly language as the same, just as a lot of Baroque music seems the same to us, because the music tends to follow particular forms and sequences. Baroque music is structured like a weaving on a loom, and it's no accident that punch cards were invented to run looms before they were used to run computers.
It's easy to take a superior attitude toward these innovators, but this is unfair. We owe a great debt to these people. They invented the algorithms we use, even if the music does seem a bit limited at times. (Except for Bach, and Backus, of course.)
The Classical period was a time of standardization. Most of our modern instruments took their current form during this period, and this continued the trend of turning virtuosity into a marketable and portable commodity. Being able to program in FORTRAN was like being able to play the piano forte. It was a skill you could use on someone else's machinery. Mozart could now go on tour.
The Romantic era was a time of seeing how far the classical forms could be stretched. And considerably stretched they were, in Beethoven and Mahler, as well as PL/1 and COBOL. The word “excessive” has been applied to all of them, as it will always be applied to anyone or anything that attempts to sling the entire universe around by any of its handles. But this is difficult at the best of times.
Finally, the typical overreaction took place, and we arrived in the Modern era, in which subtlety and minimalism were mandated, and antiquated cultural expectations were thrown over and thrown out. Reductionism and deconstructionism were the order of the day, from Bartok to Cage, and from Pascal to C. Music wasn't allowed to be tonal, and computer languages weren't allowed to do fancy I/O. All the gadgetry had to be visible and exposed. Everything had to look difficult, so we got stuck in the Turing Tar Pit.
Of course, this is all oversimplified, and every language has aspects of each of these periods in it. And languages specialize in other ways: BASIC is like pop music. Tune into REXX for your easy listening classics. Tcl is fuzzy like jazz—you get to improvise a lot, and you're never quite sure who is interpreting what. Python is like MTV—it rocks, but it gets to be much of a sameness after half an hour or so.
Lisp is like church music down through the ages, adapting to what ever the popular culture is, from organ to electric guitar to synthesizer. That would make Scheme a kind of cult music, sung simply but with great fervor to an acoustic guitar.
C++ is like movie music, of titanic proportions, yet still culturally derivative by and large. Especially large. Sometimes it's hard to sit through the whole movie. And yet, as an intentionally Post-Modern language, it's kinda fun, and gets the job done.
As for Java, using a subset of movie music, it's attempting to be the basis for every good feeling everywhere, the ground of all emotional being. Muzak. It's everywhere you want to be.
Shell programming is a 1950s juke box—great if it has your song already.
And of course, any language touched by ANSI starts to sound distinctly operatic.
So where does Perl fit in to this glorious mess? Like C++, Perl is a Post-Modern language by design, unashamedly reconstructionist and derivative. Perl is neo-Baroque, neo-Classical, neo-Romantic, and even, in spots, neo-Modern.
What musical genre encompasses so much? Where can you find every thing from Wagner to “Shave and a Haircut, Two Bit”? Where can you find multiple levels of abstraction, accessible to newbies and oldsters alike? What kind of music admits everything from harmonica to accordion to pipe organ? What music is object-oriented, in good one-to-one correspondence with the main action? What music is good for programming in the small, but can be expanded to feature length as necessary? What music parodies every thing in the world, yet leaves you feeling good about the world? What music is Perl?
Why, cartoon music, of course. That's all folks!
Larry Wall doesn't mind being blamed for the invention of Perl, to the extent that you can blame any one person for it, which you can't, so there.