[dkarapetyan]

Who's the target audience of this exactly? I already see a language pragma, do notation, liftIO, parser combinators.

Hamming has this great set of lectures on how he became a world renowned scientist and in one of the lectures he explains why Ada failed and other languages succeeded. The difference was that Ada was designed logically and most successful languages were designed psychologically. Even when government contracts mandated Ada people still wrote in Fortan and hand translated to Ada. You can watch the videos and take from it what you will.

A minimal bash file is`#!/bin/bash`. A minimal turtle file is already way too long and logical.

The set of videos: https://www.youtube.com/playlist?list=PL2FF649D0C4407B30.

[nandemo]

Presumably the target is existing haskellers. Basically, "if you use Haskell, here's something to help you use it for shell scripts too".

I don't think it's reasonable to assert that Ada "failed" (e.g. it runs on large passenger airplanes), but in any case that's kinda beside the point, TFA isn't primarily about Haskell evangelism/advocacy.

> language pragma, do notation, liftIO, parser combinators.

Arguably, all of this is within the reach of an intermediate-level Haskell programmer. OverloadedStrings is considered a basic pragma.

[Gabriel439]

The target audience is non-Haskell programmers, and if you don't think the tutorial is good enough to onboard such a programmer then I consider that a bug against the library. I would actually appreciate if people submitted Github issues highlighting any pedagogical problem with the tutorial.

I think the use of `liftIO` is a reasonable objection. When I wrote the library I had the choice of utomatically pre-wrapping all `IO` commands with `liftIO` for the user (making them all `Shell` commands) by default. However, I decided not to do that for two reasons:

* If you do that you can't use them outside of a `Shell` any longer * The user has to learn `liftIO` anyway if they want to use `IO` actions not provided by the `turtle` library. I didn't want to teach the user a leaky abstraction

I don't see any issue with `do` notation is bad. Same thing with parser combinators, which are just strings in the simple case, and the "Patterns" section of tutorial has a table showing you how to convert regular expression idioms to `Pattern`s:

http://hackage.haskell.org/package/turtle-1.0.0/docs/Turtle-...

The language pragma is sort of a grey area. I decided to keep it because it doesn't take a long time to explain and it significantly increases the usability of the library.

[dkarapetyan]

I think you mentioned at some point the goal is to get folks using large python scripts to use this instead. I would be very curious to hear how that progresses.

[pjmlp]

Ada might have failed on OS, but that is just because few startups that based their workstation OS in UNIX succeeded in the market at large.

C goes hand-in-hand with UNIX, so clearly no UNIX vendor would have it in their SDK and UNIX developers weren't willing to pay for tools.

As history has shown, the moment UNIX vendors started doing "Home" and "Pro" editions, GCC got lots of help.

As Ada talks at FOSDEM show, it is present everywhere where safety matters and its use has been slowly increasing since the Internet has shown how bad idea is to connect C code to the outside world.

http://www.kb.cert.org/vuls/byupdate?open=&start=1&count=10

[_yosefk]

I think there's much (~10x) more C code than Ada code everywhere where safety matters. (No hard data, just a feeling from experience - if you have hard data proving me wrong, do share.)

Also, it's not just Unix that's written in C or a descendant - there's also, well, Windows, and a load of embedded RTOSes.

If Ada made you as productive as C with extra benefits or something to that effect, you'd expect Ada to succeed at the marketplace at a scale at least comparable to C's - especially with the government support it had which put C at a disadvantage, not?

[pjmlp]

> I think there's much (~10x) more C code than Ada code everywhere where safety matters

Probably, but using C dialects and certification processes that make C just look like Ada with another syntax.

http://www.misra-c.com/MISRAChome/tabid/181/Default.aspx

http://en.wikipedia.org/wiki/DO-178B

http://www.programmingresearch.com/solutions/medical-devices...

> Also, it's not just Unix that's written in C or a descendant - there's also, well, Windows, and a load of embedded RTOSes.

Windows did not exist when UNIX was created.

MS-DOS was based on CP/M which copied ideas from UNIX into home computers. So while C didn't had a special place in home computers, UNIX was gaining adoption in the enterprise even Microsoft had their own UNIX, Xenix.

Which they used to cross compile some of their MS-DOS applications.

So it was only natural that when they started developing Windows, they used their in-house languages and both Quick Basic and Quick Pascal were not that up to the task, leaving C as the option.

Embedded RTOS are traditionally POSIX compliant, wich leads again to C.

Microsof is actually moving away from C, this is why they don't care about compliance any longer and speak about C++ and .NET Native.

Even their latest C99 related changes are only related to what ANSI C++11/14 require and a few key open source projects that they wanted to see supported.

Which is kind of funny, because Microsoft was the last C compiler vendor in the home computing space, to add a C++ compiler to their tools, with Microsoft C/C++ 7.0.

> If Ada made you as productive as C with extra benefits or something to that effect, you'd expect Ada to succeed at the marketplace at a scale at least comparable to C's - especially with the government support it had which put C at a disadvantage, not?

Not if people are expected to pay for the compilers.

[madawan]

Would it be possible to create a /bin/turtle script which prepends those import and language statements? That way all the boilerplate that's needed would be "main = do ...", which seems acceptable imo.

[npsimons]

As a working programmer and a bit of a language geek, a few years ago I decided to try to get as many programming languages as possible installed on my dev machines. From this, I eventually tried to get as many of them "scriptable" as possible, creating at a bare minimum a "Hello, world!" template that could be run from the command line. I like having options, or a bare minimum, having things around to play with/learn when I've got down time.

I remember something in "Mythical Man-Month" that extolled the virtues of scripting programming for concept exploration, and I've often felt this is one of the major advantages traditionally scriptable languages have over compiled. Once you can run a program without compiling it, iteration tends to go faster.

So sure, some languages require more boilerplate to get started than others, but I've got templates for that, and I happily scripted almost all the exercises in "Thinking in C++" because it just made working them out faster, even in emacs where I can bind the compile key to any command I can dream of.