ciel/docs/libraries.md

# Libraries

To see the full list of dependencies, see the `ciel.asd` project definition or this [dependencies list](dependencies.md).

## Data structures

### Generic and nested access to datastructures (access)

From [Access](https://github.com/AccelerationNet/access/%0A), we import `access` and `accesses` (plural).

It's always

```lisp
(access my-structure :elt)
```

for an alist, a hash-table, a struct, an object… Use `accesses` for nested access (specially useful with JSON).

### Hash-table utilities (Serapeum)

We import functions from Serapeum. <https://github.com/ruricolist/serapeum/blob/master/REFERENCE.md#hash-tables>

To see their full list with their documentation, see [serapeum](serapeum.md).
``` txt
:dict
:do-hash-table ;; see also trivial-do
:dict*
:dictq  ;; quoted
:href  ;; for nested lookup.
:href-default
:pophash
:swaphash
:hash-fold
:maphash-return
:merge-tables
:flip-hash-table
:set-hash-table
:hash-table-set
:hash-table-predicate
:hash-table-function
:make-hash-table-function
:delete-from-hash-table
:pairhash
```

Here's how we can create a hash-table with keys and values:

``` lisp
;; create a hash-table:
(dict :a 1 :b 2 :c 3)
;; =>
(dict
 :A 1
 :B 2
 :C 3
)
```

In default Common Lisp, you would do:

```lisp
  (let ((ht (make-hash-table :test 'equal)))
    (setf (gethash :a ht) 1)
    (setf (gethash :b ht) 2)
    (setf (gethash :c ht) 3)
    ht)
;; #<HASH-TABLE :TEST EQUAL :COUNT 3 {1006CE5613}>
```

As seen above, hash-tables are pretty-printed by default.

You can toggle the representation with `toggle-pretty-print-hash-table`, or by setting

```lisp
(setf *pretty-print-hash-tables* nil)
```

in your configuration file.

### Sequences utilities (Alexandria, Serapeum)

From *Serapeum* we import:

``` txt
:assort
:batches
:runs
:partition
:partitions
:split-sequence
```

And from [Alexandria](https://common-lisp.net/project/alexandria/draft/alexandria.html):

``` text
:iota
:flatten
:shuffle
:random-elt
:length=
:last-elt
:emptyp
```

and some more.

### String manipulation (str)

Available with the `str` prefix.

<https://github.com/vindarel/cl-str/>

Data formats
------------

### CSV

You have [cl-csv](https://github.com/AccelerationNet/cl-csv), under its `cl-csv` package name and the `csv` local nickname.

```lisp
;; read a file into a list of lists
(cl-csv:read-csv #P"file.csv")
=> (("1" "2" "3") ("4" "5" "6"))

;; read csv from a string (streams also supported)
(cl-csv:read-csv "1,2,3
4,5,6")
=> (("1" "2" "3") ("4" "5" "6"))

;; read a file that's tab delimited
(cl-csv:read-csv #P"file.tab" :separator #\Tab)

;; loop over a CSV for effect
(let ((sum 0))
  (cl-csv:do-csv (row #P"file.csv")
    (incf sum (parse-integer (nth 0 row))))
  sum)
```

See also:

-   [auto-text](https://github.com/defunkydrummer/auto-text), automatic detection for text files (encoding, end of line, column width, csv delimiter etc). [inquisitor](https://github.com/t-sin/inquisitor) for detection of asian and far eastern languages.
-   [CLAWK](https://github.com/sharplispers/clawk), an AWK implementation embedded into Common Lisp, to parse files line-by-line.

### JSON

We use [cl-json](https://common-lisp.net/project/cl-json/cl-json.html) ([GitHub](https://github.com/hankhero/cl-json)). It has a `json` nickname.

To encode an object to a string, use `encode-json-to-string`:

```lisp
(json:encode-json-to-string (list (dict :a 1)))
;; "[{\"A\":1}]"
```

To decode from a string: `decode-json-from-string`.

To encode or decode objects from a *stream*, use:

-   `encode-json object &optional stream`
-   `decode-json &optional stream`

as in:

```lisp
(with-output-to-string (s)
   (json:encode-json (dict :foo (list 1 2 3)) s))
;; "{\"FOO\":[1,2,3]}"

(with-input-from-string (s "{\"foo\": [1, 2, 3], \"bar\": true, \"baz\": \"!\"}")
  (json:decode-json s))
;; ((:|foo| 1 2 3) (:|bar| . T) (:|baz| . "!"))
```

cl-json can encode and decode from objects. Given a simple class:

```lisp
(defclass person ()
  ((name :initarg :name)
   (lisper :initform t)))
```

We can encode an instance of it:

```lisp
(json:encode-json-to-string (make-instance 'person :name "you"))
;; "{\"NAME\":\"you\",\"LISPER\":true}"
```

By default, cl-json wants to convert our lisp symbols to camelCase, and the JSON ones to lisp-case. We disable that in the `ciel-user` package.

You can set this behaviour back with:

```lisp
(setf json:*json-identifier-name-to-lisp* #'json:camel-case-to-lisp)
(setf json:*lisp-identifier-name-to-json* #'json:lisp-to-camel-case)
```

Date and time
-------------

The [local-time](https://common-lisp.net/project/local-time/) package is available.

See also [awesome-cl\#date-and-time](https://github.com/CodyReichert/awesome-cl#date-and-time) and the [Cookbook](https://lispcookbook.github.io/cl-cookbook/dates_and_times.html).

Databases
---------

Mito and SxQL are available.

<https://lispcookbook.github.io/cl-cookbook/databases.html>


GUI (ltk)
---------

We ship [ltk](http://www.peter-herth.de/ltk/ltkdoc/).

The Tk toolkit is nearly ubiquitous and simple to use. It doesn't have a great deal of widgets, but it helps anyways for utility GUIs. Moreover, it doesn't look aweful (as it did back), it has themes to look nearly native on the different platforms.

Here's how it looks like on Mac:

![](https://lispcookbook.github.io/cl-cookbook/assets/gui/ltk-on-macos.png)

You have other GUI options a quickload away (Qt4, Gtk, IUP, Nuklear, not mentioning LispWorks CAPI…): <https://lispcookbook.github.io/cl-cookbook/gui.html>

Here's how to start with Ltk:

-   either put yourself in the `ltk-user` package:

```lisp
(in-package :ltk-user)
```

-   either `use` ltk:

```lisp
(use-package :ltk)
```

Use the `with-ltk` macro to define your GUI, use `make-instance` + a widget name to create it, and use the `grid` to position widgets.

```lisp
(with-ltk ()
  (let ((button (make-instance 'button :text "hello")))
    (grid button 0 0)))
```

Read more: <https://lispcookbook.github.io/cl-cookbook/gui.html#tk>

Iteration
---------

We ship `iterate` and `for` so you can try them, but we don't import their symbols.

See <https://lispcookbook.github.io/cl-cookbook/iteration.html> for examples, including about the good old `loop`.

We import macros from [trivial-do](https://github.com/yitzchak/trivial-do/), that provides `dolist`-like macro to iterate over more structures:

-   `dohash`: dohash iterates over the elements of an hash table and binds key-var to the key,

value-var to the associated value and then evaluates body as a tagbody that can include declarations. Finally the result-form is returned after the iteration completes.

-   `doplist`: doplist iterates over the elements of an plist and binds key-var to the key, value-var to

the associated value and then evaluates body as a tagbody that can include declarations. Finally the result-form is returned after the iteration completes.

-   `doalist`: doalist iterates over the elements of an alist and binds key-var to the car of each element,

value-var to the cdr of each element and then evaluates body as a tagbody that can include declarations. Finally the result-form is returned after the iteration completes.

-   `doseq*`: doseq\* iterates over the elements of an sequence and binds position-var to the index of each

element, value-var to each element and then evaluates body as a tagbody that can include declarations. Finally the result-form is returned after the iteration completes.

-   `doseq`: doseq iterates over the elements of an sequence and binds value-var to successive values

and then evaluates body as a tagbody that can include declarations. Finally the result-form is returned after the iteration completes.

-   `dolist*`: dolist\* iterates over the elements of an list and binds position-var to the index of each

element, value-var to each element and then evaluates body as a tagbody that can include declarations. Finally the result-form is returned after the iteration completes.


Numerical and scientific
------------------------

We import `mean`, `variance`, `median` and `clamp` from Alexandria.

We import functions to parse numbers (Common Lisp only has `parse-integer` by default).

[parse-float](https://github.com/soemraws/parse-float)

Similar to PARSE-INTEGER, but parses a floating point value and returns the value as the specified TYPE (by default `*READ-DEFAULT-FLOAT-FORMAT*`). The DECIMAL-CHARACTER (by default \#.) specifies the separator between the integer and decimal parts, and the EXPONENT-CHARACTER (by default \#e, case insensitive) specifies the character before the exponent. Note that the exponent is only parsed if RADIX is 10.

``` text
ARGLIST: (string &key (start 0) (end (length string)) (radix 10) (junk-allowed nil)
        (decimal-character .) (exponent-character e)
        (type *read-default-float-format*))
```

From [parse-number](https://github.com/sharplispers/parse-number), we import:

``` text
:parse-number
:parse-positive-real-number
:parse-real-number
```

``` text
PARSE-NUMBER
  FUNCTION: Given a string, and start, end, and radix parameters,
  produce a number according to the syntax definitions in the Common
  Lisp Hyperspec.
  ARGLIST: (string &key (start 0) (end nil) (radix 10)
          ((float-format *read-default-float-format*)
           *read-default-float-format*))
```

See also [cl-decimals](https://github.com/tlikonen/cl-decimals) to parse and format decimal numbers.

We don't ship *Numcl*, a Numpy clone in Common Lisp, but we invite you to install it right now with Quicklisp:

```lisp
(ql:quickload "numcl")
```

### Plotting

We import the [vgplot](https://github.com/volkers/vgplot) plotting library, an interface to `gnuplot`.

It has a very good demo: just call

    (vgplot:demo)

![](assets/vgplot.png)

Here's a simple example to create a new plot:

~~~lisp
 (vgplot:plot #(1 2 3) #(0 -2 -17) "silly example")
 (vgplot:title "Simple curve")
 (vgplot:text 1.2 -14 "Plot vectors with legend and add a title")
~~~

This will open a gnuplot window, which you can interfere with by
entering more vgplot commands.

`format-plot` allows direct commands to the running gnuplot process:

~~~lisp
(vgplot:format-plot t "set size square 0.5,0.5~%")
(vgplot:replot)
~~~

You can open other plots in parallel with `new-plot`, and create subplots in the same window with `subplot`.

You can graph data from files:

~~~lisp
(vgplot:plot (first (vgplot:load-data-file "data.csv")))
~~~

Close plots with `close-plot` or `close-all-plots`.

Explore the demo [here](https://github.com/volkers/vgplot/blob/master/demo.lisp).



Regular expressions
-------------------

Use `ppcre`.

See <https://common-lisp-libraries.readthedocs.io/cl-ppcre> and <https://lispcookbook.github.io/cl-cookbook/regexp.html>

Threads, monitoring, scheduling
-------------------------------

We ship:

[Bordeaux-Threads](https://common-lisp.net/project/bordeaux-threads/) (`bt` prefix)

[Lparallel](https://lparallel.org/)

[Moira](https://github.com/ruricolist/moira) (monitor and restart background threads)

[trivial-monitored-thread](http://quickdocs.org/trivial-monitored-thread/)

> Trivial Monitored Thread offers a very simple (aka trivial) way of spawning threads and being informed when one any of them crash and die.

[cl-cron](http://quickdocs.org/cl-cron/api) (see the sources on [our fork here](https://github.com/ciel-lang/cl-cron))

For example, run a function every minute:

```lisp
(defun say-hi ()
  (print "Hi!"))
(cl-cron:make-cron-job #'say-hi)
(cl-cron:start-cron)
```

Wait a minute to see some output.

Stop all jobs with `stop-cron`.

`make-cron`'s keyword arguments are:

```lisp
(minute :every) (step-min 1) (hour :every) (step-hour 1) (day-of-month :every)
(step-dom 1) (month :every) (step-month 1) (day-of-week :every)
(step-dow 1)
(boot-only nil) (hash-key nil))
```

HTTP and URI handling
---------------------

See:

-   Dexador. Use the `dex` nickname or the `http` local nickname.
-   Quri
-   Lquery

```lisp
(dex:get "http://my.url")
```

Web
---

We ship:

-   Hunchentoot
-   Easy-routes

<https://lispcookbook.github.io/cl-cookbook/web.html>

Development
-----------

### Testing (Fiveam)

The [FiveAM](https://common-lisp.net/project/fiveam/docs/) test framework is available for use.

Below we create a package to contain our tests and we define the most simple one:

```lisp
(defpackage ciel-5am
  (:use :cl :5am))

(in-package :ciel-5am)

(test test-one
  (is (= 1 1)))
```

Run the test with:

``` txt
(run! 'test-one)

Running test TEST-ONE .
 Did 1 check.
    Pass: 1 (100%)
    Skip: 0 ( 0%)
    Fail: 0 ( 0%)

T
NIL
NIL
```

If the test fails you will see explanations:

``` txt
> (run! 'test-one)

Running test TEST-ONE .f
 Did 2 checks.
    Pass: 1 (50%)
    Skip: 0 ( 0%)
    Fail: 1 (50%)

 Failure Details:
 --------------------------------
 TEST-ONE []:

1

 evaluated to

1

 which is not

=

 to

2


 --------------------------------

NIL
(#<IT.BESE.FIVEAM::TEST-FAILURE {1007307ED3}>)
NIL
```

Use `run` to not print explanations.

You can use `(!)` to re-run the last run test.

You can ask 5am to open the interactive debugger on an error:

``` example
(setf *debug-on-error* t)
```

### Logging (log4cl)

<https://github.com/sharplispers/log4cl/>

``` example
(log:info …)
```

### Discoverability of documentation (repl-utilities' readme, summary,…)

We use `readme` and `summary` from [repl-utilities](http://quickdocs.org/repl-utilities/).

Learn more with:

``` example
(readme repl-utilities)
```

### printv

[printv](https://github.com/danlentz/printv)

```lisp
 (:printv
  (defvar *y*)
  (defparameter *x* 2)
  (setf *y* (sqrt *x*))
  (setf *y* (/ 1 *y*)))

;; This produces the following text to PRINTV's output stream, and still results in the same returned value: 0.70710677.

;;;   (DEFVAR *Y*) => *Y*
;;;   (DEFPARAMETER *X* 2) => *X*
;;;   (SETF *Y* (SQRT *X*)) => 1.4142135
;;;   (SETF *Y* (/ 1 *Y*)) => 0.70710677

```

### Getting a function's arguments list (trivial-arguments)

<https://github.com/Shinmera/trivial-arguments>

```lisp
(defun foo (a b c &optional d) nil)
(arglist #'foo)
;; (a b c &optional d)
```