> there’s a definite correlation between how easy it is to parse for the computer and for you

I’m not sure that’s true tbh. Exhibit A: natural language. Exhibit B: Polish notation.

▲ chrismorgan 4 days ago | parent [-]

I don’t see how either of those exhibits demonstrate your point.

I believe various research has shown that humans and machines parse natural language in rather similar ways. Garden-path sentences <https://en.wikipedia.org/wiki/Garden-path_sentence> are a fun demonstration of how human sentence parsing involves speculation and backtracking.

Polish notation is easy for both to parse; humans only struggle because they’re not so familiar with it.

(By adulthood, human processing biases extremely heavily toward the familiar. Computer parsing has to be implemented from scratch, so there’s not so much concept of familiarity, though libraries can encapsulate elements of parsing.)

▲ saghm 3 days ago | parent | next [-]

> Polish notation is easy for both to parse; humans only struggle because they’re not so familiar with it

I think you're downplaying the significance of this. The lack of familiarity is exactly what I'd argue makes a huge difference in practice even if theoretically the way our brains parse things isn't that different. We spend so much time reading and writing words that it requires effort to learn how to parse each specific symbol-oriented thing we might want to learn how to read. To add to the parent comment's examples, I'll throw in Brainfuck, which is an extremely simple language for a machine to learn to parse that's literally named for how impenetrable it looks to people at first glance.

"Simple if I spend the time to learn it" is not the same as "simple without having to spend time to learn it", and for some things, the fact that the syntax essentially ignores some of the finer details is the main feature rather than a drawback. When everyone I work with can read and write markdown good enough for us not to have major issues, and junior engineers can get up to basically the same level of competence in it without needing a lot of hand holding, it's just not worth the effort for me to try to convince everyone to use RST even if it is better in theory. The total amount of time I've spent dealing with the minor annoyances in markdown in my life is less than the amount of time it would probably take me to convince even one of my coworkers that we should switch all of our READMEs to RST.

▲ thiht 3 days ago | parent | prev [-]

> I don’t see how either of those exhibits demonstrate your point.

Natural language is easy to do for a human and a hard computing problem.

Polish notation is extremely simple to implement, but relatively "hard" for a human, even knowing the rules and how to read it. See: `+ * - 15 6 / 20 4 ^ 2 3 - + 7 8 * 3 2`

▲ chrismorgan 3 days ago | parent | next [-]

> Natural language is easy to do for a human and a hard computing problem.

You ever see someone learning a new language? They struggle hard on more complex sentences.

It’s easy for us because we’ve practised it so much.

> + * - 15 6 / 20 4 ^ 2 3 - + 7 8 * 3 2

To begin with, you’re missing an operator. I’ll assume another leading +.

  + + * - 15 6 / 20 4 ^ 2 3 - + 7 8 * 3 2

Now, if you use infix, you have to have at least some of the parentheses, in this case actually only one pair, given rules of operator precedence, associativity and commutativity:

  (15 - 6) * 20 / 4 + 2 ^ 3 + 7 + 8 - 3 * 2

But you may well just parenthesise everything, it makes solving easier:

  ((((15 - 6) * (20 / 4)) + (2 ^ 3)) + ((7 + 8) - (3 * 2)))

And you know how you go about solving it? Calculating chunks from the inside out, and replacing them with their values:

  (((    9    *     5   ) +    8   ) + (  15    -    6   ))
  ((         45           +    8   ) +          9         )
  (                      53          +          9         )
                                    62

Coming back to Polish notation—you know what? It’s exactly the same:

  (+ (+ (* (- 15 6) (/ 20 4)) (^ 2 3)) (- (+ 7 8) (* 3 2)))
  (+ (+ (* 9 5) 8) (- 15 6))
  (+ (+ 45 8) 9)
  (+ 53 9)
  62

For arithmetic at least, it’s not hard. You’re just not accustomed to it.

	▲	Arainach 3 days ago \| parent [-]
		This is a really weird hill to die on. HP tried hard to make RPN a thing and even among engineers eventually lost out to notation that is easier to work with. People read in one direction - in English left to right. They read faster and comprehend better when they can move in that direction without constantly jumping back and forth. > (15 - 6) * 20 / 4 + 2 ^ 3 + 7 + 8 - 3 * 2 (15-6)20/4 can be read as one block left to right 2^3 can be read as one block left to right. Jump back to the operator (count: 1) 7 + 8 continue left to right 32 is a block, jump back to operator (count: 2) So that reads left to right as speakers of most western languages do with only two context shifts. Now let's try RPN: > + + * - 15 6 / 20 4 ^ 2 3 - + 7 8 * 3 2 ignore, ignore, ignore, ignore. 15, 6, context shift (1) ignore? 20, context shift (2) 4, context shift (3) ignore? 2 (wait, am I supposed to use that caret? I'm already confused and I've used RPN calculators before. Counting this as a context shift (4)) 3, context shift (5) two more operators and I don't really understand why any more basically, RPN makes you context shift every single time you enter a number. It is utter chaos to understand of jumping back and forth and trying to remember what came before and happens next. Even if you're used to it it's dramatically worse for humans, and no one cares how much software it takes to parse. Incidentally from my experience with RPN calculators I'd have expected 15 6 - 20 * 4 / 2 3 ^ + 7 + 8 + 3 2 * - Though it's not really better since instead of context shifting after every number you have to context shift after ever operator to try to remember what's on the stack

▲ fluidcruft 3 days ago | parent | prev [-]

Polish notation looks like a nightmare for expressing something like a partial differential equation. Even combining fractions looks like it's going to be a nightmare.