What I learned from C that made me a better Pascal programmer

I snuck into programming through the back door. At first I wanted to be an architect, but I went to school in the days before CAD and, well, India Ink and I didn’t get along. You could easily spend hours/days on a drawing and if, at the end, you made one little botch you had to start over.   I think I wanted refactoring before I even knew what it was.

After architecture, I started taking math classes and I considered majoring in math, but it felt a bit selfish to me. I didn’t think that I could feel useful plugging away at theorems. Also, I wasn’t sure I really had the aptitude. I liked math but proof was harder than I expected.

My next stop was engineering. It looked like fun, but I started to have nightmares about designing vacuum cleaners for a living. It's not that I don't like vacuum cleaners, it's just that I don’t have a deep passion for them (applause for the people who do).

It all changed for me when I got a co-op job at a company that was writing demographics software. I worked with a computer running SAS-PC programs, and I became curious about programming.  It looked like fun. I started to learn more and then, with all of the fire of youth, decided that if I was really going to make a career of programming, I had to know that I could really be good at it. I had to know that I could really excel.

How did I convince myself? I decided that I would teach myself C. I’d read that C was the hardest programming language out there, so I figured that, hey, if I could learn C as a first language, by myself, programming might be thing that I should throw myself into. I started writing little graphics programs, displaying the results of formulas I’d read about from chaos theory. It was exasperating but fun. I stayed after work, exploring all of the nuances of C compiler command line. I stumbled through pointers and indirection, manual memory management, and printf debugging. It was hard slogging through alone, but I did it. I convinced myself that I could program.

The next step was to change my major to computer science and start taking classes. My first programming class was Introduction to Programming with Pascal. For a self-taught C programmer, nothing could be more gruesome. You couldn’t just open a file, you had to pass an input or an output parameter to your program. You couldn’t really touch memory, you had all of these little bits of syntax in the way that didn’t seem to map to anything real.

It was hard for me to know what was really happening behind the scenes, and I was a bit shaken by the experience. But, nonetheless, I thrived. I took more courses and I dutifully went to the computer lab every afternoon and logged onto the VAX/VMS operating system(!) and went about my work – until – one day late in the term – I looked at the terminal of the woman next to me and I saw something strange. It was an array subscript out of bounds error.

I’d never seen one before.

After a bit of reflection, I understood why. When you are programming in C, nothing is going to save you. After you spend hours debugging an errant pointer dancing over memory, you just learn not to do that.

These days, I have a greater appreciation for Niklaus Wirth's work (although I don't really have fond memories of Pascal) and I do appreciate it when a language's runtime or static checker lets me know when I've flubbed up in a particularly grievous yet stupid way.  But, after all is said and done, I'm glad that C taught me that lesson. 

Safety is good, but so is the possibility of danger.  It keeps us thinking rigorously, and there's value in that.

 

This blog was inspired by Reginald Braithwaite's Three blog posts I'd love to read (and one that I wouldn't)

Comments

[Reg Braithwaite]

Great post, thank you!

[chan kok leong]

"Safety is good, but so is the possibility of danger. It keeps us thinking rigorously, and there's value in that."

that's a very good point. Nicely articulated.

[she]

In these times, a higher level language is needed.

C will still be at the core.

[Steve Freeman]

Pascal was a teaching language, never really intended for production, so it had lots of hand-holding. The Modula languages that it inspired were consistently better than the C equivalents at the time but, as Gabriel pointed out, they lost in the market. I don't have the reference, but I remember some research showing that it was cheaper to develop in Modula-2 than C because there were fewer mistakes. Great days. Sigh.

S.