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The March of Progress (in programming language syntax :)

alan.dipert.org

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Re: The March of Progress (in programming language syntax :)

#21

Post by lloeki »

astrobe_ wrote: post #13
lclarkmichalek wrote: post #12

None of these are syntax. `printf` in C or scala/groovy is a function call, which relates to the language's API, the C++ use of streams is an API decision, Java being funky is due to its API (and its semantics to a lesser extent). The only language I can think of off the top of my head where print would be syntax would be python, and even then 1) that's only for versions <=2, and 2) the formatting would still be an A…

printf/scanf do have a syntax. But you're not wrong saying it is not part of the syntax of the language stricto sensu. I personnaly don't like the printf/scanf style, which unfortunately often prevails in newer languages. I definitely prefer the string interpolation method, or just plain string concatenation.

> I definitely prefer the string interpolation method, or just plain string concatenation.

You're mixing things up; the point of printf is to format data, of which "%s / %s / %s" is a subset. Constructs like "0x%04x" or "%12s" really are about formatting.

Re: The March of Progress (in programming language syntax :)

#22

Post by spicyj »

MBCook wrote: post #10

Heh. Cute. As a Java programmer, I agree that NumberFormat looks ridiculous there. It's a lot of work for a single number to string conversion. Luckily, since Java 5 there is a printf function: System.out.printf(...);

That's in the article.

Re: The March of Progress (in programming language syntax :)

#25

Post by eliasmacpherson »

acqq wrote: post #19
eliasmacpherson wrote: post #15

Earlier quoted context omitted.

char format[10] = "%10.3f%10.4f%10.3f%10.4f%10.3f%10.4f%4d"; printf( format, x, y, a, b, c, d, n ); You can get similar behavior from C, reusing the format specification? No idea if this was true in the K&R days though.

But not the repetition inside of one specification which I illustrated in the example (note the 3 before the braces in the 2 FORMAT), and much more important, no compile-time type checking and compile time code generation for output. In C it's a library call and most of the processing happens at the run-time. And yes I know of gcc checks. Still whoever uses some printf variant today, misses some aspects of what was w…

I was only addressing your first point, not your second example which you demonstrated clearly earlier. The recursive syntax is impressive alright - thanks for sharing it. I was unaware of it, as I'm sure many others were. I was not suggesting C has a built in method for achieving the results of the second example. I'm not certain about the compile time versus execution time distinctions. The compiler behaviour could depend on the mutability of the objects. It's possible a C #define constant would cause different compile time behaviour to variables. I'm not a compiler expert in either language so I can't provide any insight in any case.

Those GCC checks you mentioned are handy and would have avoided a bug in production code a colleague encountered a few years ago, but I imagine they are more recent than C in 1982, and certainly more recent than Fortran in 1956

#define formata "%10.3f%10.4f"

#define formatb(z) z z z "%4d\n"

printf( formatb(formata), x, y, a, b, c, d, n );

The example you've given is thought provoking!

Re: The March of Progress (in programming language syntax :)

#26

Post by hippo_crete »

In 1956 there was such a thing as "the compiler business". Companies bought compilers.

Now, most programmers only speculate what a compiler does. They are so focused on language details.

Few want to write compilers. Many want to write yet another new language.

Re: The March of Progress (in programming language syntax :)

#27

Post by jasomill »

lloeki wrote: post #21
astrobe_ wrote: post #13

Earlier quoted context omitted.

printf/scanf do have a syntax. But you're not wrong saying it is not part of the syntax of the language stricto sensu. I personnaly don't like the printf/scanf style, which unfortunately often prevails in newer languages. I definitely prefer the string interpolation method, or just plain string concatenation.

> I definitely prefer the string interpolation method, or just plain string concatenation. You're mixing things up; the point of printf is to format data, of which "%s / %s / %s" is a subset. Constructs like "0x%04x" or "%12s" really are about formatting .

Yes, but they're often used for "mere" interpolation, especially in languages where, rightly or wrongly, string concatenation is believed to be inefficient. I personally do this nine times out of ten, if only out of habit.

For my part, I've never personally liked the use of "+", in particular, to denote concatenation, for the (admittedly silly) reason that string concatenation is not commutative. If nothing else, it's a bit of a slippery slope to even more dubious operator overloads, though not nearly so much as C++'s bloody I/O "operators"!

Re: The March of Progress (in programming language syntax :)

#28

Post by rbanffy »

acqq wrote: post #14

The proper list starts with: 1956: Fortran I: PRINT 1, X 1 FORMAT (F10.2) Fortran was able to use the same format specification for more than one print statement, that's why the format statement is referenced by number. It was even able to do repeats, for example this code from 1956 PRINT 2, X, Y, A, B, C, D, N 2 FORMAT ( 3 ( F10.3, F10.4 ), I4 ) is an equivalent of the following C: printf( "%10.3f%10.4f%10.3f%10.4f%…

I think you started your code on the wrong column... ;-)

Re: The March of Progress (in programming language syntax :)

#29

Post by lloeki »

jasomill wrote: post #27
lloeki wrote: post #21

Earlier quoted context omitted.

> I definitely prefer the string interpolation method, or just plain string concatenation. You're mixing things up; the point of printf is to format data, of which "%s / %s / %s" is a subset. Constructs like "0x%04x" or "%12s" really are about formatting .

Yes, but they're often used for "mere" interpolation, especially in languages where, rightly or wrongly, string concatenation is believed to be inefficient. I personally do this nine times out of ten, if only out of habit. For my part, I've never personally liked the use of "+", in particular, to denote concatenation, for the (admittedly silly) reason that string concatenation is not commutative. If nothing else, it'…

It's not uncommon to use + for groups even if they're not abelian, esp. with near-rings.

This takes all its importance with duck-typing, as syntactic sugar of binary operators will be translated to a method call, e.g in Ruby a + b becomes a.+(b) [0]. while in Python it's a.__add__(b) [1]. The result might be commutative, but the call and evaluation order certainly is not.

[0] http://ruby-doc.org/core-1.9.3/Fixnum.html#method-i-2B [1] http://docs.python.org/reference/datamodel.html#object.__add...

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