# xintsession README #
Release: 0.4alpha (2021-11-01)
## Usage ##
xintsession.tex is to be used with etex (or pdftex or the other engines
with Plain as preloaded format) *interactively on the command line*.
It will load [xintexpr](http://www.ctan.org/pkg/xint) and
[polexpr](http://www.ctan.org/pkg/polexpr).
To start a session:
1. Execute `etex xintsession`,
2. An `>>>` invite appears, and computations can begin!\
\
Start entering input, terminate it via a semi-colon `;`.
Say `&help` for help and `&bye` to quit.
In more details: if available at your locale use `rlwrap etex xintsession` to
benefit from arrow keys navigation and other improvements such as parentheses
highlighting. Alternatively, execute `rlwrap etex` and enter `xintsession` at
the `**` prompt.
One can also use the `-jobname` option of `etex` at this step.
At my locale I added `alias xs="rlwrap etex xintsession"` to my `.bashrc`
so I only have to type `xs` at the command line.
The above explanations have been tested on a Unixen (Mac OS), and probably
`rlwrap` is not available on all platforms, but it is not a requirement.
Here is a sample session (spaces do not matter):
>>> 1+1/2+1/3+1/4+1/5;
@_1 137/60
>>> @_^3;
@_2 2571353/216000
>>> add(1/i, i=1..50);
@_3 13943237577224054960759/3099044504245996706400
>>> &fp
fp mode (16 digits)
>>> @_;
@_4 4.499205338329425
>>> add(1/i, i=1..1000);
@_5 7.485470860550346
>>> &pol
pol mode (i.e. function definitions use \poldef)
>>> P(x):=(x-0.1)^3 (x+1.8)^2 (x^10 - (100x-1)^2);
P = x^15+33*x^14/10+219*x^13/100-865*x^12/1000+936*x^11/10000-324*x^10/100000-1
0000*x^7-328000*x^6/10-2124100*x^5/100+9084700*x^4/1000-11111900*x^3/10000+5198
500*x^2/100000-74160*x/100000+324/100000
--> &GenFloat(P) lets P become usable as function in fp mode
--> &ROOTS(P) (resp. &ROOTS(P,N)) finds all rational roots exactly and
all irrational roots with at least 10 (resp. N) fractional digits
>>> &ROOTS(P,30)
Solving for real roots of P and assigning them (please wait...)
(mult. 1) RootP_1 = -3.164772734675337090200909653480...
(mult. 2) RootP_2 = -1.8
(mult. 1) RootP_3 = 0.009999999999000000000499999999...
(mult. 1) RootP_4 = 0.010000000001000000000500000000...
(mult. 3) RootP_5 = 0.1
(mult. 1) RootP_6 = 3.159772703424837079727026834533...
Square-free irrational part: x^10-10000*x^2+200*x-1
--> &REFINEROOTS(P,N) to extend real irr. roots to N fractional digits
>>> &bye
Did I say something wrong?
Session transcript written on xintsession-211101_18h17.tex
)
No pages of output.
Transcript written on xintsession.log.
As this example illustrates, the computational engine can work in
various modes: exact, fp, int, and pol (the `&ROOTS()` will work in
any mode the same once the polynomial as been defined in pol mode).
Say `&fp=number` at the `>>>` prompt to activate floating point mode
with `number` digits of precision.
If ill-formed input drops you deep into TeX error interaction mode,
try hitting `S` as it may work to bring you back to normal session.
For additional explanations, enter `&help` at the `>>>` prompt.
## Change log ##
- 0.4alpha (2021-11-01)
- add `&GenFloat` interface to `\PolGenFloatVariant`
- add `&ROOTS` and `&REFINEROOTS` interface to under-the-hood
usage of the
[polexpr](http://www.ctan.org/pkg/polexpr) facilities
allowing to get all real roots of the given polynomial
to arbitrary precision (and all rational roots exactly)
- 0.3b (2021-07-01)
- fix output still uses `(@_)` when a variable is defined
but the parentheses were dropped a while ago in general
- 0.3a (2021-06-08)
- fix extremely weird `0.3` breakage of user function definition
interface, caused by last line being `\endinput\xintsession`,
and the latter using `\scantokens` in certain circumstances
- fix extra `(` in a help panel
- 0.3 (2021-05-31)
- implement `>>>` primary and `...` secondary invite prompts
- breaking: rename `\xintresume` into `\xintsession`
- 0.2b (2021-05-23)
- use `\errorcontextlines=0` regime (if not paused)
- load `xintexpr` with `\newlinechar` set to `10` to activate
nicer error messages coming with `xintexpr 1.4g`
- add help panel navigation via `n`, `p`, `q` and `1`, ..., `5`
- fix catcode of @ was set to letter
- fix version was not updated to `0.2a` in banner
- fix some spaces in help and welcome panels
- 0.2a (2021-05-06)
- fix help panels mentioning topics obsoleted by `xintexpr 1.4f`
- 0.2 (2021-05-05)
- fix typos in help panels, improve welcome panel
- fix "can't send `\par` to background typesetting"
- track `xintexpr 1.4f`
- add `&fp=N` parameterized floating point mode interface
- 0.1 (2021-04-13)
Initial release
## License ##
Copyright (c) 2021 Jean-François Burnol
See documentation of package [xintexpr](http://www.ctan.org/pkg/xint) for
contact information.
This Work may be distributed and/or modified under the conditions of the
LaTeX Project Public License version 1.3c. This version of this license
is in
>
and version 1.3 or later is part of all distributions of LaTeX version
2005/12/01 or later.
This Work has the LPPL maintenance status author-maintained.
The Author of this Work is Jean-François Burnol.
This Work consists of the package files xintsession.tex and README.md