5 ms·

What if C++ looked more like Python or CoffeeScript?

66 points by SupremumLimit 12y ago

shurcooL 12y ago
This really reminds me of a similar attempt for Go, called iGo [1]. There are a lot more cases to handle for C++. [1] https://news.ycombinator.com/item?id=7444459 https://news.ycombinator.com/item?id=7444459
- SupremumLimit 12y ago
  Interesting, thanks for the link. This does look quite similar!
  - DAddYE 12y ago
    Yep, reading your article I found myself in it and "go" is very simple (compared to c++) however main issue is the readability of function calls with multi lambda arguments.
- DAddYE 12y ago
  Thank you!!!!!!!
mrbrowning 12y ago
> I’m quite fond of languages with minimal syntax. Maybe this is the Lisp enthusiast in me, but as someone who does the bulk of their workaday programming in Python I still feel compelled to say that it's a perverse worldview that holds up Python as an instance of "minimal syntax."
- SupremumLimit 12y ago
  Well, I didn't say that Python is the pinnacle of minimalism :) However, it's hard to reduce C++ to Lisp syntax without completely changing the nature of the language.
pwang 12y ago
This is an interesting exercise, but most of the suggestions on the page are just cosmetic, and do not address the fundamental challenge of C++ - perhaps the biggest divergence between Python and C++: A core design principle of C++ is that you do not pay (performance-wise) for what you don't use. This leads to all sorts of nasty things like object slicing, law of big 3, template preprocessor hell just to get pseudo-generics. A core design principle of Python is that you should pay the minimum cognitive burden for what you are not using. Don't care to customize object dispatch? Then you don't need to know about descriptors and __slots__ just to write a simple class. No amount of syntactic cargo culting is going to bridge this gap. The whitespace and lack of semicolons is not why people embrace Python. Just as removing integer types and sensible scoping from C++ won't make it Javascript, replacing braces with tabs is not going to make it Python.
- sanxiyn 12y ago
  This is obviously not trying to address divergence between Python and C++. Stop attacking strawmen. Nobody sane would imagine C++ in Python syntax would appeal to Python programmers. On the other hand, C++ in Python syntax would appeal to C++ programmers who prefer Python syntax to C++ syntax. I am one of them, and this is a good try.
- 127 12y ago
  I disagree that greatly reducing the mental overhead of visual processing is merely a cosmetic change. This may just be an issue of taste, or familiarity, but I greatly prefer not presenting the same information twice. Once with characters and the second time with indentation. Why not just indentation? Also it forces people to make all hierarchical code blocks immediately visible, instead of being free to put them anywhere they like.
Qworg 12y ago
This is the exact opposite of what I want in C++. The use of characters to clearly delineate code sections and scope is a strong benefit of C++ over these other languages. They're not a "source of errors" - they allow a competent programmer the opportunity to quickly reason about the structure of the code. If vertical compression is an issue - get a bigger monitor or an IDE that allows for code hiding. It is also far better to have a "oops, I missed a brace" error that your compiler/IDE catches, versus a "man, why does my program keep seg faulting unexpectedly" error that takes hours to track down since you missed a single tab somewhere.
- thinkpad20 12y ago
  I'm not sure what your complaint is here. With whitespace sensitivity, "oops, I missed a brace" and "oops, I missed a tab" is exactly the same. Your compiler/IDE would catch it, just as it would any other syntax error. The difference (arguably) is that it's easier to spot (because that's how humans read code). I would argue that whitespace sensitivity makes those kinds of errors less likely, not more. Curly braces everywhere lead to a lot of visual noise, and can obscure what the code is doing. Consider the classic C syntax error: if (foo > bar) printf("Hey!\n"); return foo; return bar; With whitespace sensitivity, this would do what you think it would. With curly braces, it's misleading.
  - ufo 12y ago
    Whitespace sensitivity also introduces some similar problems. For example, if the printf is indented with spaces and the return foo is indented with tabs, the return will be put outside the if, even though it looks like its inside. TBH, the real problem with C is not the braces - its that braces are optional.
    - meowface 12y ago
      >For example, if the printf is indented with spaces and the return foo is indented with tabs, the return will be put outside the if, even though it looks like its inside. Python 3 deals with this by throwing a warning about inconsistent use of tabs and spaces before it even finishes parsing the file (so basically before runtime). There's no reason why any other language can't do the same.
porges 12y ago
This looks really error-prone to me. Have you looked at previous attempts, such as SPECS? http://www.csse.monash.edu.au/~damian/papers/HTML/ModestProposal.html http://www.csse.monash.edu.au/~damian/papers/HTML/ModestProp...
- SupremumLimit 12y ago
  Any specific reasons why it's error-prone? I've just seen someone post a link to SPECS in the comments to the post - it's interesting but takes a very different direction. I wanted the code to remain recognisably C++.
- kcbanner 12y ago
  Any python developer will tell you they have accidentally indented or un-indented some code, and that error took hours to find
  - SupremumLimit 12y ago
    Well I've written quite a bit of CoffeeScript, and while I had a few issues with incorrect code translation to JavaScript, I don't recall ever having problems with mis-indented code.
  - pseudonom- 12y ago
    As another point to triangulate from, Haskell is also whitespace-sensitive and I have never had a non-trivial whitespace error in it.
  - 3d7718844 12y ago
    I've been programming in Python for 4 years and I've never spent hours trying to find an indentation error. It comes up, sure, but no more frequently than any other syntax error in a different language and there are usually dead giveaways indicating what happened. Most IDEs/editors have options to view whitespace characters, so if you're worried about encountering a bug from this you can always enable that feature. It's really a non-issue.
    - 12y ago
sanxiyn 12y ago
This doesn't seem to address http://en.wikipedia.org/wiki/Most_vexing_parse http://en.wikipedia.org/wiki/Most_vexing_parse at all. On the other hand, if you don't care about backward compatibility, I guess completely eliminating constructor syntax in favor of C++11 uniform initialization syntax is a good solution as any. (But maybe curly brace haters won't like that solution.)
- SupremumLimit 12y ago
  I think uniform initialization needs a lot of work before it can become the one and only mechanism for initialization. Currently it isn't anywhere near uniform enough. But aside from that, I think it would be fine to use curly braces for initialization as long as they are freed from the burden of delimiting code blocks.
- jeorgun 12y ago
  I'd be fully in support of that if it weren't for the fact that initializer_lists end up causing their own sets of issues. For instance, type-inference is completely borked: auto foo{tmp}; results in std::initializer_list<decltype(tmp)> Not to mention issues such as std::vector<int>{ 3, 4 } // => [3, 4] vs std::vector<int>( 3, 4 ) // => [4, 4, 4, 4] Unless some alternate syntax is proposed for initializer_lists, the old syntactic forms are kind of indispensable.
  - nly 12y ago
    There's a proposal to fix the 'foo' case but, as an outsider, it's unclear whether it will be fixed in time for C++14. [0] The vector case is unfortunate, but I'd personally argue the defect is in the vector class. There's no significant performance advantage, that I can see, to the (n, T) construction over a default construction followed by v.resize(n, T). [0] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3922.html http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n392...
andrewstuart 12y ago
Why can't IDEs just hide all the brackets and replace them with sane whitespace structure?
- marvy 12y ago
  If your only goal is to read the code, then they could probably do it, after working out a few minor issues. The question is, how do you enter new code? With braces, which vanish as you type, or with whitespace, which means the braces exist only on disk? And if you mess up, how do you cope with the compiler errors?
- singlecomment 12y ago
  Why add extra layers?
- corysama 12y ago
  I use this as a compromise to keep myself from writing code in a format that would anger my coworkers. https://github.com/lukesdm/little-braces https://github.com/lukesdm/little-braces
keypusher 12y ago
I love Python and it is one of my primary development languages, but I have come to believe meaningful indentation was a bad idea. As Rob Pike said in the recent Go conference keynote: "It is a profound mistake to have your semantics depend on invisible characters". Braces also make parsing and auto-formatting easier and better. It seems Go struck a good balance with with a newline after statements (no semicolon necessary), and braces for all structures.
- gohrt 12y ago
  Newlines are invisible characters. Tabs+spaces are the real problem with python indentation. It should be a compiler error to mix them in a file.
  - shurcooL 12y ago
    I would not classify newlines as invisible characters. Except maybe the last newline in the file. Invisible characters are those that you can't tell if they're present or not. Assuming there are visible characters following, a newline can be clearly "seen" because it shifts the remaining text one line lower.
    - Someone 12y ago
      You must have never encountered a file with mixed line endings. Somebody should design an esoteric language that uses LF to separate statements in a block and CRLF to separate blocks. Alternatively, find a unicode line break character that editors recognize, but C doesn't treat as a line break, and sneak it into a source file at a strategic place to introduce a back door.
      - gmjosack 12y ago
        Semi-related, you might be interested in Whitespace http://en.wikipedia.org/wiki/Whitespace_(programming_language) http://en.wikipedia.org/wiki/Whitespace_(programming_languag...
  - 12y ago
minaandrawos 12y ago
How about exploring a modern language like Google GO (Golang)? Go was designed exactly for the purpose of having a performance that could be compared to some extent to powerful languages like C/C++ and in the same time maintains a Python like syntax. I have programmed with both languages and I'd say by the end of the day both languages are powerful tools in your developer's toolbox however Go is a very attractive choice when it comes to rapid to develop performant applications
- lukeholder 12y ago
  I agree, would be an interesting to see the same experiment done for Go. Will have a stab!
  - SupremumLimit 12y ago
    As somebody posted in another comment, it looks like it's already been done: https://news.ycombinator.com/item?id=7444459 https://news.ycombinator.com/item?id=7444459
deleted 12y ago
[deleted]
kcbanner 12y ago
Seems like a step in exactly the wrong direction
sanxiyn 12y ago
This doesn't seem to allow single line if or while statements, because parentheses are optional. I like single line if when it is appropriate. (Python allows single line if by using colons.) Apart from my taste, C preprocessor macros can't expand to more than a single line, so this seems to prevent macros expanding to contain control structures. Is there an easy fix?
- SupremumLimit 12y ago
  You could do it by separating the body with a semicolon: if something_is_true(); log("warning!") I haven't really considered the preprocessor as I prefer to avoid it as much as possible.
  - sanxiyn 12y ago
    This doesn't work. "if a; if b; c; d" is then an ambiguous parse to both "if (a) { if (b) { c; d; } }" and "if (a) { if (b) { c; } d; }". If you decide to parse one way, how do you write the other one in a single line?
    - SupremumLimit 12y ago
      I'd make this parse as "if (a) { if (b) { c; d; } }" and leave it at that. One of the reasons for significant indentation is to discourage this kind of code layout because it's hard to read.
      - sanxiyn 12y ago
        Okay, concretely, I'd like to see a translation of this real-world C++ code (taken from V8): #define RETURN_OBJECT_UNLESS_EXCEPTION(ISOLATE, RETURN_VALUE, RETURN_EMPTY) \ if (!__allocation__.IsRetry()) { \ __object__ = __allocation__.ToObjectChecked(); \ if (__object__ == (ISOLATE)->heap()->exception()) { RETURN_EMPTY; } \ RETURN_VALUE; \ }
drivingmenuts 12y ago
If it looked more like Python or CoffeeScript, then it wouldn't be C++ anymore.
- SupremumLimit 12y ago
  My goal was to make the code remain recognisably C++, but remove some of the noise.
jbeja 12y ago
Nobody needs that
claudius 12y ago
$ wc -c a.cpp t.cpp 399 a.cpp 380 t.cpp 779 total $ cat t.cpp #include <iostream> using namespace std; namespace utils { template<typename T> T square(const T& n) { return n * n; } } int main() { int input(0); auto message("Please enter a positive number"); cout << message << ":\n"; cin >> input; if (input>0) { cout << "Result: " << utils::square(input) << "\n"; } else { cout << message << "\n"; } return 0; } $ cat a.cpp #include <iostream> using namespace std namespace utils template<typename T> auto square(const T& n) return n * n int main() auto input = 0 auto message = "Please enter a positive number" cout << message << ":" << endl cin >> input if input > 0 cout << "Result: " << utils::square(10) << endl else cout << message << endl return 0 I am not entirely convinced that t.cpp has any more or less noise than a.cpp and where exactly there is any sort of gain from this – I had more trouble indenting the second piece of code properly for HN than the first.
- SupremumLimit 12y ago
  If you squint in just the right way so as not to see any of the braces, semicolons and parentheses in the first example, then naturally we are going to disagree about the amount of noise :)
  - claudius 12y ago
    Maybe my visual capabilities are just more limited than yours :) That said, I wouldn’t call things like ‘end of statement’ or ‘end of this block’ noise. They have very real effects and using ; and } over "\n" and "\t" seems a decent choice. Natural languages have ".", "," and ";" for a reason, too; although one could argue for paragraphs to be roughly (but only roughly!) block-equivalents and inherently whitespacy.
616c 12y ago
Since no one has said so yet, and I quickly searched the comments, the answer is basically a language called Nimrod. It shows up here a lot, and not many people use it still. Time will tell.
zvrba 12y ago
If you think that syntax is THE problem that needs to be solved to make C++ less error-prone, you don't know shit about C++.
srean 12y ago
It has not been mentioned in the original post or the comments yet, so here is a working prototype of a similar idea https://github.com/pfultz2/Pythy https://github.com/pfultz2/Pythy (for some specific value of working, you will need Clang) Its birth lies here Having it all: Pythy syntax for C++ [1]. It was a nice read. Unfortunately cpp-next seems to be down right now. Let me try to find it in Google's cache or internet archive. Here it is https://web.archive.org/web/20130820172127/http://cpp-next.com/archive/2011/11/having-it-all-pythy-syntax/ https://web.archive.org/web/20130820172127/http://cpp-next.c... [1] http://cpp-next.com/archive/2011/11/having-it-all-pythy-syntax/ http://cpp-next.com/archive/2011/11/having-it-all-pythy-synt...
- SupremumLimit 12y ago
  I think generic lambdas provide for this in C++14.
flohofwoe 12y ago
This looks neat on first glance and on small code samples, but I've had so many messed up whitespaces after merging branches that in the real world this would be just another way to shoot yourself in the foot. I really like python for scripting up into the 10k lines-of-code area, but for bigger projects (and teams with more then - say - 3 coders) I wouldn't even consider a dynamically typed language, let alone a language where intendations and newlines are language constructs. I don't really find the example at the end of the article much more readable (even though it "cheats" a bit by using the C++11 auto keyword and range-based for loop), on the contrary, the white space on the left side looks more messy then on the right side to me. C++ code which has a lot of STL containers and complex templates does look ugly though, that's why I prefer to either not use this, or hide it under typedefs and decltypes. I also don't like the new auto keyword very much, the compiler SHOULD complain when someone on the team changes types around.
pskocik 12y ago
What if I wanted to take a peek at this article without giving up my email address? If only there was an easy way to stop JavaScript from blocking my page view with that subscribe request …
ASneakyFox 12y ago
Python is easier to type but its harder to read. Ides that help you code faster are a better investment of time than a language that's easier to write in notepad. My ide does brackets and indention for me. I never think about them. They're just there for my reading pleasure. I like these things its easier to follow the code when reading.
Executor 12y ago
I would support this if you can remove header files. It is hell to manage function prototypes. Let the compiler figure that out with "public/private" keywords.

66 points by SupremumLimit 12y ago

This really reminds me of a similar attempt for Go, called iGo [1]. There are a lot more cases to handle for C++. [1] https://news.ycombinator.com/item?id=7444459 https://news.ycombinator.com/item?id=7444459

SupremumLimit 12y ago
Interesting, thanks for the link. This does look quite similar!
- DAddYE 12y ago
  Yep, reading your article I found myself in it and "go" is very simple (compared to c++) however main issue is the readability of function calls with multi lambda arguments.
DAddYE 12y ago
Thank you!!!!!!!

mrbrowning 12y ago

> I’m quite fond of languages with minimal syntax. Maybe this is the Lisp enthusiast in me, but as someone who does the bulk of their workaday programming in Python I still feel compelled to say that it's a perverse worldview that holds up Python as an instance of "minimal syntax."

SupremumLimit 12y ago
Well, I didn't say that Python is the pinnacle of minimalism :) However, it's hard to reduce C++ to Lisp syntax without completely changing the nature of the language.

pwang 12y ago

This is an interesting exercise, but most of the suggestions on the page are just cosmetic, and do not address the fundamental challenge of C++ - perhaps the biggest divergence between Python and C++: A core design principle of C++ is that you do not pay (performance-wise) for what you don't use. This leads to all sorts of nasty things like object slicing, law of big 3, template preprocessor hell just to get pseudo-generics. A core design principle of Python is that you should pay the minimum cognitive burden for what you are not using. Don't care to customize object dispatch? Then you don't need to know about descriptors and __slots__ just to write a simple class. No amount of syntactic cargo culting is going to bridge this gap. The whitespace and lack of semicolons is not why people embrace Python. Just as removing integer types and sensible scoping from C++ won't make it Javascript, replacing braces with tabs is not going to make it Python.

sanxiyn 12y ago
This is obviously not trying to address divergence between Python and C++. Stop attacking strawmen. Nobody sane would imagine C++ in Python syntax would appeal to Python programmers. On the other hand, C++ in Python syntax would appeal to C++ programmers who prefer Python syntax to C++ syntax. I am one of them, and this is a good try.
127 12y ago
I disagree that greatly reducing the mental overhead of visual processing is merely a cosmetic change. This may just be an issue of taste, or familiarity, but I greatly prefer not presenting the same information twice. Once with characters and the second time with indentation. Why not just indentation? Also it forces people to make all hierarchical code blocks immediately visible, instead of being free to put them anywhere they like.

Qworg 12y ago

This is the exact opposite of what I want in C++. The use of characters to clearly delineate code sections and scope is a strong benefit of C++ over these other languages. They're not a "source of errors" - they allow a competent programmer the opportunity to quickly reason about the structure of the code. If vertical compression is an issue - get a bigger monitor or an IDE that allows for code hiding. It is also far better to have a "oops, I missed a brace" error that your compiler/IDE catches, versus a "man, why does my program keep seg faulting unexpectedly" error that takes hours to track down since you missed a single tab somewhere.

thinkpad20 12y ago
I'm not sure what your complaint is here. With whitespace sensitivity, "oops, I missed a brace" and "oops, I missed a tab" is exactly the same. Your compiler/IDE would catch it, just as it would any other syntax error. The difference (arguably) is that it's easier to spot (because that's how humans read code). I would argue that whitespace sensitivity makes those kinds of errors less likely, not more. Curly braces everywhere lead to a lot of visual noise, and can obscure what the code is doing. Consider the classic C syntax error: if (foo > bar) printf("Hey!\n"); return foo; return bar; With whitespace sensitivity, this would do what you think it would. With curly braces, it's misleading.
- ufo 12y ago
  Whitespace sensitivity also introduces some similar problems. For example, if the printf is indented with spaces and the return foo is indented with tabs, the return will be put outside the if, even though it looks like its inside. TBH, the real problem with C is not the braces - its that braces are optional.
  - meowface 12y ago
    >For example, if the printf is indented with spaces and the return foo is indented with tabs, the return will be put outside the if, even though it looks like its inside. Python 3 deals with this by throwing a warning about inconsistent use of tabs and spaces before it even finishes parsing the file (so basically before runtime). There's no reason why any other language can't do the same.

porges 12y ago

This looks really error-prone to me. Have you looked at previous attempts, such as SPECS? http://www.csse.monash.edu.au/~damian/papers/HTML/ModestProposal.html http://www.csse.monash.edu.au/~damian/papers/HTML/ModestProp...

SupremumLimit 12y ago
Any specific reasons why it's error-prone? I've just seen someone post a link to SPECS in the comments to the post - it's interesting but takes a very different direction. I wanted the code to remain recognisably C++.
kcbanner 12y ago
Any python developer will tell you they have accidentally indented or un-indented some code, and that error took hours to find
- SupremumLimit 12y ago
  Well I've written quite a bit of CoffeeScript, and while I had a few issues with incorrect code translation to JavaScript, I don't recall ever having problems with mis-indented code.
- pseudonom- 12y ago
  As another point to triangulate from, Haskell is also whitespace-sensitive and I have never had a non-trivial whitespace error in it.
- 3d7718844 12y ago
  I've been programming in Python for 4 years and I've never spent hours trying to find an indentation error. It comes up, sure, but no more frequently than any other syntax error in a different language and there are usually dead giveaways indicating what happened. Most IDEs/editors have options to view whitespace characters, so if you're worried about encountering a bug from this you can always enable that feature. It's really a non-issue.
  - 12y ago

sanxiyn 12y ago

This doesn't seem to address http://en.wikipedia.org/wiki/Most_vexing_parse http://en.wikipedia.org/wiki/Most_vexing_parse at all. On the other hand, if you don't care about backward compatibility, I guess completely eliminating constructor syntax in favor of C++11 uniform initialization syntax is a good solution as any. (But maybe curly brace haters won't like that solution.)

SupremumLimit 12y ago
I think uniform initialization needs a lot of work before it can become the one and only mechanism for initialization. Currently it isn't anywhere near uniform enough. But aside from that, I think it would be fine to use curly braces for initialization as long as they are freed from the burden of delimiting code blocks.
jeorgun 12y ago
I'd be fully in support of that if it weren't for the fact that initializer_lists end up causing their own sets of issues. For instance, type-inference is completely borked: auto foo{tmp}; results in std::initializer_list<decltype(tmp)> Not to mention issues such as std::vector<int>{ 3, 4 } // => [3, 4] vs std::vector<int>( 3, 4 ) // => [4, 4, 4, 4] Unless some alternate syntax is proposed for initializer_lists, the old syntactic forms are kind of indispensable.
- nly 12y ago
  There's a proposal to fix the 'foo' case but, as an outsider, it's unclear whether it will be fixed in time for C++14. [0] The vector case is unfortunate, but I'd personally argue the defect is in the vector class. There's no significant performance advantage, that I can see, to the (n, T) construction over a default construction followed by v.resize(n, T). [0] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3922.html http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n392...

andrewstuart 12y ago

Why can't IDEs just hide all the brackets and replace them with sane whitespace structure?

marvy 12y ago
If your only goal is to read the code, then they could probably do it, after working out a few minor issues. The question is, how do you enter new code? With braces, which vanish as you type, or with whitespace, which means the braces exist only on disk? And if you mess up, how do you cope with the compiler errors?
singlecomment 12y ago
Why add extra layers?
corysama 12y ago
I use this as a compromise to keep myself from writing code in a format that would anger my coworkers. https://github.com/lukesdm/little-braces https://github.com/lukesdm/little-braces

keypusher 12y ago

I love Python and it is one of my primary development languages, but I have come to believe meaningful indentation was a bad idea. As Rob Pike said in the recent Go conference keynote: "It is a profound mistake to have your semantics depend on invisible characters". Braces also make parsing and auto-formatting easier and better. It seems Go struck a good balance with with a newline after statements (no semicolon necessary), and braces for all structures.

gohrt 12y ago
Newlines are invisible characters. Tabs+spaces are the real problem with python indentation. It should be a compiler error to mix them in a file.
- shurcooL 12y ago
  I would not classify newlines as invisible characters. Except maybe the last newline in the file. Invisible characters are those that you can't tell if they're present or not. Assuming there are visible characters following, a newline can be clearly "seen" because it shifts the remaining text one line lower.
  - Someone 12y ago
    You must have never encountered a file with mixed line endings. Somebody should design an esoteric language that uses LF to separate statements in a block and CRLF to separate blocks. Alternatively, find a unicode line break character that editors recognize, but C doesn't treat as a line break, and sneak it into a source file at a strategic place to introduce a back door.
    - gmjosack 12y ago
      Semi-related, you might be interested in Whitespace http://en.wikipedia.org/wiki/Whitespace_(programming_language) http://en.wikipedia.org/wiki/Whitespace_(programming_languag...
- 12y ago

minaandrawos 12y ago

How about exploring a modern language like Google GO (Golang)? Go was designed exactly for the purpose of having a performance that could be compared to some extent to powerful languages like C/C++ and in the same time maintains a Python like syntax. I have programmed with both languages and I'd say by the end of the day both languages are powerful tools in your developer's toolbox however Go is a very attractive choice when it comes to rapid to develop performant applications

lukeholder 12y ago
I agree, would be an interesting to see the same experiment done for Go. Will have a stab!
- SupremumLimit 12y ago
  As somebody posted in another comment, it looks like it's already been done: https://news.ycombinator.com/item?id=7444459 https://news.ycombinator.com/item?id=7444459

deleted 12y ago

[deleted]

kcbanner 12y ago

Seems like a step in exactly the wrong direction

sanxiyn 12y ago

This doesn't seem to allow single line if or while statements, because parentheses are optional. I like single line if when it is appropriate. (Python allows single line if by using colons.) Apart from my taste, C preprocessor macros can't expand to more than a single line, so this seems to prevent macros expanding to contain control structures. Is there an easy fix?

SupremumLimit 12y ago
You could do it by separating the body with a semicolon: if something_is_true(); log("warning!") I haven't really considered the preprocessor as I prefer to avoid it as much as possible.
- sanxiyn 12y ago
  This doesn't work. "if a; if b; c; d" is then an ambiguous parse to both "if (a) { if (b) { c; d; } }" and "if (a) { if (b) { c; } d; }". If you decide to parse one way, how do you write the other one in a single line?
  - SupremumLimit 12y ago
    I'd make this parse as "if (a) { if (b) { c; d; } }" and leave it at that. One of the reasons for significant indentation is to discourage this kind of code layout because it's hard to read.
    - sanxiyn 12y ago
      Okay, concretely, I'd like to see a translation of this real-world C++ code (taken from V8): #define RETURN_OBJECT_UNLESS_EXCEPTION(ISOLATE, RETURN_VALUE, RETURN_EMPTY) \ if (!__allocation__.IsRetry()) { \ __object__ = __allocation__.ToObjectChecked(); \ if (__object__ == (ISOLATE)->heap()->exception()) { RETURN_EMPTY; } \ RETURN_VALUE; \ }

drivingmenuts 12y ago

If it looked more like Python or CoffeeScript, then it wouldn't be C++ anymore.

SupremumLimit 12y ago
My goal was to make the code remain recognisably C++, but remove some of the noise.

jbeja 12y ago

Nobody needs that

claudius 12y ago

$ wc -c a.cpp t.cpp 399 a.cpp 380 t.cpp 779 total $ cat t.cpp #include <iostream> using namespace std; namespace utils { template<typename T> T square(const T& n) { return n * n; } } int main() { int input(0); auto message("Please enter a positive number"); cout << message << ":\n"; cin >> input; if (input>0) { cout << "Result: " << utils::square(input) << "\n"; } else { cout << message << "\n"; } return 0; } $ cat a.cpp #include <iostream> using namespace std namespace utils template<typename T> auto square(const T& n) return n * n int main() auto input = 0 auto message = "Please enter a positive number" cout << message << ":" << endl cin >> input if input > 0 cout << "Result: " << utils::square(10) << endl else cout << message << endl return 0 I am not entirely convinced that t.cpp has any more or less noise than a.cpp and where exactly there is any sort of gain from this – I had more trouble indenting the second piece of code properly for HN than the first.

SupremumLimit 12y ago
If you squint in just the right way so as not to see any of the braces, semicolons and parentheses in the first example, then naturally we are going to disagree about the amount of noise :)
- claudius 12y ago
  Maybe my visual capabilities are just more limited than yours :) That said, I wouldn’t call things like ‘end of statement’ or ‘end of this block’ noise. They have very real effects and using ; and } over "\n" and "\t" seems a decent choice. Natural languages have ".", "," and ";" for a reason, too; although one could argue for paragraphs to be roughly (but only roughly!) block-equivalents and inherently whitespacy.

616c 12y ago

Since no one has said so yet, and I quickly searched the comments, the answer is basically a language called Nimrod. It shows up here a lot, and not many people use it still. Time will tell.

zvrba 12y ago

If you think that syntax is THE problem that needs to be solved to make C++ less error-prone, you don't know shit about C++.

srean 12y ago

It has not been mentioned in the original post or the comments yet, so here is a working prototype of a similar idea https://github.com/pfultz2/Pythy https://github.com/pfultz2/Pythy (for some specific value of working, you will need Clang) Its birth lies here Having it all: Pythy syntax for C++ [1]. It was a nice read. Unfortunately cpp-next seems to be down right now. Let me try to find it in Google's cache or internet archive. Here it is https://web.archive.org/web/20130820172127/http://cpp-next.com/archive/2011/11/having-it-all-pythy-syntax/ https://web.archive.org/web/20130820172127/http://cpp-next.c... [1] http://cpp-next.com/archive/2011/11/having-it-all-pythy-syntax/ http://cpp-next.com/archive/2011/11/having-it-all-pythy-synt...

SupremumLimit 12y ago
I think generic lambdas provide for this in C++14.

flohofwoe 12y ago

This looks neat on first glance and on small code samples, but I've had so many messed up whitespaces after merging branches that in the real world this would be just another way to shoot yourself in the foot. I really like python for scripting up into the 10k lines-of-code area, but for bigger projects (and teams with more then - say - 3 coders) I wouldn't even consider a dynamically typed language, let alone a language where intendations and newlines are language constructs. I don't really find the example at the end of the article much more readable (even though it "cheats" a bit by using the C++11 auto keyword and range-based for loop), on the contrary, the white space on the left side looks more messy then on the right side to me. C++ code which has a lot of STL containers and complex templates does look ugly though, that's why I prefer to either not use this, or hide it under typedefs and decltypes. I also don't like the new auto keyword very much, the compiler SHOULD complain when someone on the team changes types around.

pskocik 12y ago

What if I wanted to take a peek at this article without giving up my email address? If only there was an easy way to stop JavaScript from blocking my page view with that subscribe request …

ASneakyFox 12y ago

Python is easier to type but its harder to read. Ides that help you code faster are a better investment of time than a language that's easier to write in notepad. My ide does brackets and indention for me. I never think about them. They're just there for my reading pleasure. I like these things its easier to follow the code when reading.

Executor 12y ago

I would support this if you can remove header files. It is hell to manage function prototypes. Let the compiler figure that out with "public/private" keywords.