I've come to like the printf() way of doing things.  I used it extensively in Using Gretl for Principles of Econometrics.  It first appears in chapter 2, but for some reason I didn't bother explaining the syntax until chapter 5 (pages 94 and 95).  Something else to fix! 

As has been said in this thread, it's a fairly standard way of printing numbers and text that yields predictable results.  Stata has a very simple "display" command that allows you to print text and numbers with less fuss, e.g.,

di "The sample size is " e(N)

but it is very basic and there is no real control over the formatting.  I know there are fancier and more complicated ways of formatting output in Stata, like 'esttab' for tabular data, but it uses the same C like syntax as gretl. 

Lee  

On Mon, Sep 19, 2016 at 3:35 PM, Allin Cottrell <cottrell@wfu.edu> wrote:
On Mon, 19 Sep 2016, Sven Schreiber wrote:

Am 18.09.2016 um 23:35 schrieb Allin Cottrell:
On Sun, 18 Sep 2016, Sven Schreiber wrote:

(Side remark: What _is_ confusing about string literals in hansl is
the way how literals are given without quotes in a foreach loop --as
in "loop foreach i peach pear plum"--, and probably in a few more
places; but I've said that before.)

Granted. There are some places in hansl syntax where we really require a
string literal (or a set of same) but in the interest of (supposed)
user-friendliness we accept an unquoted version of the argument. I'm
prepared to admit that was probably a mistake ;-)

And I'm willing to admit that maintaining too much backwards compatibility in a relatively young language as hansl might backfire in those cases...

 Well, OK, we could revisit that.

OK, but I'm not sure that people always know what's good for them! (See the US electorate's flirtation with Donald Trump.) The thing is, those dumbed-down printf variants might look quite nice at first -- say, if you have just one string and one variable to print -- but they don't take you far, and in the end you have to learn printf anyway.

I must say I'm surprised to hear that and I don't agree at all. This is the kind of argument that we usually hear against GUI programs and also against syntax features like significant whitespace and so forth. Basically most of the stuff that makes up gretl and hansl.

 Having spent thousands of hours developing and maintaining the gretl GUI I'm not about to deprecate graphical interfaces. What we're talking about here is the relative merits of two command-line interfaces for printing information, when the exact content is not known at code-writing time. In my opinion the printf substitutes are inferior designs, and printf is not as hard to learn as many seem to think -- particularly in the context of hansl, where "%g" will do quite nicely for any numerical arguments, including "integers". (In C and other low-level languages one has a wide variety of numerical types that require their own specific conversions, and that gets more complicated.)

But anyway ...

3) A new built-in str() function as in my previous post, that does conversion to string with some default formatting (%d, %g), such that my 'eval "hey: " ~ str(somenumber)' solution would work out of the box.

 This seems to me the most acceptable of the alternative proposals,
though personally I'm not convinced it's nicer or easier than

printf "hey: %g\n", somenumber

What do others think?

Allin

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--
Lee Adkins
Professor of Economics and Department Head
Economics and Legal Studies in Business
Oklahoma State University

Email:  lee.adkins@okstate.edu
Fax: 405-744-5180
Phone: 405-744-5196
URL:  www.learneconometrics.com