Re: chapter 4 confusion

Hello Roelof:

There is something called Documentation, and I believe Christophe is quite
clear about what to do before asking around.

Instead of solving your confusions, which Christophe already did, I'll just
give the documentation here,
and I believe it is the right thing to do to refer to the doc before asking
around if you have similar confusions next time.

Here <https://ocaml.janestreet.com/ocaml-core/111.28.00/doc/core/> in the
Core Doc, you should find explanations about ln.channel.fold_lines;
Here <http://caml.inria.fr/pub/docs/manual-ocaml/> in the Standard OCaml
Doc and User's manual, you should find explanations about |>, in the Index
of values, to be more specific.

Good luck.

2014-11-07 4:22 GMT+08:00 Christophe Troestler
[email protected] [ocaml_beginners] <
[email protected]>:

>
>
> Hi,
>
> Please understand that people on this list are giving their time to
> answer your questions and that we have many other things to do so
> 1. don't expect answers to be immediate, 2. be respectful by being up
> to the point but also by showing that you have done your part of the
> work.
>
> On Thu, 6 Nov 2014 08:49:48 +0100, Roelof Wobben [email protected]
> [ocaml_beginners] wrote:
> >
> > 1) What means ln.channel.fold_lines stdin ~init part means ?
>
> The text says "In_channel.fold_lines (similar to the function
> List.fold described in Chapter 3, Lists and Patterns), which reads
> through the lines one by one, calling the provided fold function for
> each line to update the accumulator."
>
> Can you precisely voice what is not clear? You must not only read
> chapter 3 but launch the toplevel, modify the code and experiment
> with it until you precisely understand what it does.
>
> > 2) What does the |> does exactly. I know chapter 2 does explain it
> > a little
> > bit but it's still not clear to me
>
> Again, did you experiment with the code in Ch. 2 until you fully
> understood it?
>
> x |> f is equivalent to f(x) except that the priority of the
> operator |> is different from function application (which is always
> performed first) so you can use less parenthesis:
>
> x+y |> f |> g is equivalent to g(f(x+y))
>
> It also makes the "pipeline" processing "x+y" more "clear".
>
> > 3) What does ~cmp mean.
>
> This is just a named argument:
>
> ~name:value
>
> Here, it passes a comparison function (defining a total order) to the
> function sorting the lines.
>
> Best,
> C.
>  
>



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