#+title: 
# ^ no title page, but title on the slides
#+LATEX: \title{wisp}

#+LaTeX_CLASS: beamer
#+LaTeX_CLASS_OPTIONS: [presentation]
#+BEAMER_THEME: Boadilla
#+options: toc:nil

* Wisp - SRFI-119

#+latex: \vspace{1.3cm}

**                                                                :B_columns:
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***                                                                   :BMCOL:
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#+BEGIN_SRC wisp 
define : factorial n
    if : zero? n
       . 1
       * n : factorial {n - 1}
#+END_SRC

**                                                                  :B_quote:
   :PROPERTIES:
   :BEAMER_env: quote
   :END:

#+latex: \vspace{1.3cm}

\begin{center}
I love the syntax of Python, \\
but crave the simplicity and power of Lisp.
\end{center}


* Why Wisp?



** 
   :PROPERTIES:
   :BEAMER_act: <2-2>
   :END:

\centering
\Large

\textyen Hello World!\pounds

** 
   :PROPERTIES:
   :BEAMER_act: <3-4>
   :END:

\centering
\Large

Hello World!

** 
   :PROPERTIES:
   :BEAMER_act: <1-1>
   :END:

\centering
\Large

(Hello World!)

** Notes                                                            :B_quote:
   :PROPERTIES:
   :BEAMER_act: <4-4>
   :BEAMER_env: quote
   :END:

- The first and last letter are important for word recognition.¹

- Over 70% of the codelines in the Guile scheme source start with a paren \Rightarrow ceremony.

- Many people avoid Lisp-like languages because of the parens.

\footnotesize

¹: Though not all-important. See \\ [[http://www.mrc-cbu.cam.ac.uk/people/matt.davis/cmabridge/][www.mrc-cbu.cam.ac.uk/people/matt.davis/cmabridge/]]
 
* The most common letters: Lisp and Scheme are awesome

** 

\centering
\Huge
=.,":'_#?!;=

**                                                          :B_ignoreheading:
   :PROPERTIES:
   :BEAMER_env: ignoreheading
   :END:

\centering
/The most common non-letter, non-math characters in prose¹/

\vspace{0.3cm}

** 

\centering
\Huge
=()=

**                                                          :B_ignoreheading:
   :PROPERTIES:
   :BEAMER_env: ignoreheading
   :END:

\centering
/The most common paired characters¹/

**                                                          :B_ignoreheading:
   :PROPERTIES:
   :BEAMER_env: ignoreheading
   :END:


\vspace{0.5cm}

\raggedright
\footnotesize
¹: From letter distributions in newspapers, see: \\ [[https://bitbucket.org/ArneBab/evolve-keyboard-layout/src/tip/1-gramme.arne.txt][bitbucket.org/ArneBab/evolve-keyboard-layout/src/tip/1-gramme.arne.txt]]

* Wisp in a nutshell
**                                                                :B_columns:
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***                                                                   :BMCOL:
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\vspace{0.5cm}

#+BEGIN_SRC wisp 
define : factorial n
    if : zero? n
       . 1
       * n : factorial {n - 1}
#+END_SRC


***                                                                   :BMCOL:
   :PROPERTIES:
   :BEAMER_col: 0.48
   :END:
\vspace{0.5cm}

#+BEGIN_SRC wisp
(define (factorial n)
    (if (zero? n)
      1
      (* n (factorial {n - 1}))))
#+END_SRC

**                                                          :B_ignoreheading:
   :PROPERTIES:
   :BEAMER_env: ignoreheading
   :END:

\vspace{1cm}

\footnotesize

- indent as with parens, dot-prefix, inline-:, and use SRFI-105.

- Wisp uses the minimal syntax required to represent arbitrary structure: \\ Syntax justification: [[http://draketo.de/english/wisp#sec-4][draketo.de/english/wisp#sec-4]]

- Many more examples in “From Python to Guile Scheme”: \\ info: [[http://draketo.de/py2guile][draketo.de/py2guile]] \\ download: [[http://draketo.de/proj/py2guile/py2guile.pdf][draketo.de/proj/py2guile/py2guile.pdf]]

* Implementation

** REPL and reader (language wisp spec)                       :B_block:BMCOL:
   :PROPERTIES:
   :BEAMER_col: 0.57
   :BEAMER_env: block
   :END:

#+BEGIN_SRC wisp
  define-language wisp
    . #:title "Wisp Scheme Syntax.."
    . #:reader read-one-wisp-sexp
    . #:compilers `(
        (tree-il . ,compile-tree-il))
    . #:decompilers `(
        (tree-il . ,decompile-tree-il))
    . #:evaluator (lambda (x module) 
                     primitive-eval x)
    . #:printer write
    . #:make-default-environment
    lambda :
      let : : m : make-fresh-user-module
        module-define! m 'current-reader 
                          make-fluid
        module-set! m 'format simple-format
        . m
#+END_SRC

** Preprocessor (wisp.scm)                                    :B_block:BMCOL:
   :PROPERTIES:
   :BEAMER_col: 0.39
   :BEAMER_env: block
   :END:

#+BEGIN_SRC sh
guile wisp.scm tests/hello.w
#+END_SRC

#+BEGIN_SRC scheme
(define (hello who)
  (format #t "~A ~A!\n"
          "Hello" who))
(hello "Wisp")
#+END_SRC

\footnotesize
(Plan B: You can always go back)


* Applications?
**                                                                    :BMCOL:
   :PROPERTIES:
   :BEAMER_col: 0.50
   :END:

*** Example: User Scripts

#+BEGIN_SRC wisp
Enter : First_Witch
        Second_Witch
        Third_Witch

First_Witch
  When shall we three meet again
  In thunder, lightning, or in rain?
#+END_SRC

***                                                         :B_ignoreheading:
    :PROPERTIES:
    :BEAMER_env: ignoreheading
    :END:

This prints

***                                                                 :B_block:
   :PROPERTIES:
   :BEAMER_env: block
   :END:
\footnotesize
#+BEGIN_EXAMPLE
First Witch
  When shall we three meet again
  In thunder, lightning, or in rain?
#+END_EXAMPLE

***                                                         :B_ignoreheading:
    :PROPERTIES:
    :BEAMER_env: ignoreheading
    :END:

\footnotesize
- [[http://draketo.de/english/wisp/shakespeare][draketo.de/english/wisp/shakespeare]]
- Templates, executable pseudocode, REPL-interaction, ...

* Thank you!

**                                                                  :B_quote:
   :PROPERTIES:
   :BEAMER_env: quote
   :END:

»ArneBab's alternate sexp syntax is best I've seen; pythonesque, hides parens but keeps power« — Christopher Webber \\ \rightarrow [[http://dustycloud.org/blog/wisp-lisp-alternative/][dustycloud.org/blog/wisp-lisp-alternative/]]

\vspace{0.35cm}

** Try Wisp

#+BEGIN_SRC sh
guix package -i guile guile-wisp
guile --language=wisp
#+END_SRC

#+BEGIN_SRC sh
wget https://bitbucket.org/ArneBab/wisp/downloads/wisp-0.9.0.tar.gz;
tar xf wisp-0.9.0.tar.gz ; cd wisp-0.9.0/;
./configure; make check;
examples/newbase60.w 123
#+END_SRC

- [[http://draketo.de/english/wisp][http://draketo.de/english/wisp]]

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