I see this more as a) an example of how well humans can learn to ignore misdirection (the word 'move' hints at src, dest arguments) and b) the first small step towards C:

- read "mov X,Y" as "X = Y"

- adjust syntax so that it allows "X = Y" (what you see is what you think)

- similarly, replace obscure syntax for indexed memory acces by such things as "X = Y[3]"

- getting annoyed with the seemingly random limitations of the language, add an expression parser that translates "X = 2 * Y + 3" into "X = 2 * Y" and "X = X + 3", each of which gets assembled into one instruction. For now, only allow expressions that get away with only using the result register for temporaries.

- use existing macro capabilities to build a library of control flow statements such as IF and WHILE.

- introduce standard way to call subroutines.

- introduce shorthand method for doing such calls: one for the call site that takes a couple of expressions as argument, and one for function entry that uses macros such as 'int' and 'char' to pop arguments from the call stack.

By that time, one almost has K&R C.

I wrote my first compiler in M68000 assembler in a similar fashion to your steps. I started by allowing it to recognize M68000 assembler opcodes, and when found it'd just copy the line to output, otherwise it'd parse and compile the line. You could use register names and sizes directly in the statements.

So e.g.

    D0.W = 5

Would translate into:

    MOVE.W #5, D0

I didn't use macros though - handling basic argument passing is simple enough.

As soon as I had the basics of procedures/functions, simple expressions and argument passing in place I started rewriting the compiler using it.

Back in the 90's TI had a processor, maybe a DSP, I am not sure about it, which used a form of light C as their assembler.

There wasn't an Assembly language available as we tend to know.

I don't remember the name of the processor, though.

"It shows how powerful the right metaphor can be in understanding something"

Just like how I was taught the difference between "<" and ">". Our teacher drew the rest of Pac-Man around the "<" or ">" so that we'd think of "<" or ">" like the mouth of Pac-Man. It wants to eat the larger number. But that was back around 1983 when Pac-Man was all the rage (when I was drawing Pac-Man eating ghosts on my folders).

My elementary school teachers used a similar metaphor with alligators. But I never could remember which number it was that got eaten, so I just figured the bigger side was for the bigger number. Since an equal sign doesn’t have a “bigger side”, it would imply that both sides are the same. Then I wondered why they didn’t just teach that. Then I liked school even less.

(Oddly enough, my childhood intuition about equals signs isn’t historically accurate—the equality is actually supposed to be represented by the equal length of the two strokes.)

The greedy alligator always wants the bigger prey.

It took me a long time to differentiate the symbols because, before using the alligator metaphor, my teacher tried this one: cross a line that goes perperdicular to the bottom part of the symbol. If it turns into a 4 it's smaller than; otherwise, if it turns into a 7, then it's bigger than.

I remember seeing a "5 < 8" and thinking "ok, I know which number is smaller and which one is bigger, and I know how which symbol is named, but which one should I use?" For some reason it wasn't obvious to me that I should read the assertion from left to right. I just saw two numbers and I didn't know if I should indicate that one of them was bigger or that another was smaller—both assertions were true. I remember having a list of exercises to do as homework and just circling the bigger numbers in frustration.

When I hearded the alligator metaphor, however, I got it instantly.

I learned the same thing in school, but with an Alligator instead of Pac-Man =).

wow. what? what's all this stuff about alligators and pac-men? Isn't the side with two lines just bigger than the pointy side? how do these new entities help? I'm really confused by the small side being the alligator that wants to eat the big side (or did i get that wrong?), let alone the stuff about 4s and 7s!

No problem! I enjoyed reading your post. :)