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α-wwwiki :: history/regexp_evaluator/20131013-072751.txt

editor : alpha [82.255.215.190] 2013/10/13 07:27:51
_h1 regexp evaluator{sup (3)}
{div {@ style="text-align:center; color:red; background:#eee;box-shadow:0 0 8px black;"}

[[basic evaluator|?view=basic_evaluator]] | 
[[extended eval|?view=extended_evaluator]] | 
regexp eval | 
[[alpha lisp|?view=lisp_evaluator]] |
[[monodico lisp|?view=monodicolisp]]
}

_p This work is no more integrated in the wiki page and can be better analyzed and tested in the outside console :
{div {@ style="text-align:center; color:red; background:#eee;box-shadow:0 0 8px black;font-size:3em;"}[[stringlisp console|data/stringlisp/]]}

{pre {@ style="white-space:pre-wrap;font:normal 0.9em georgia"}
Rewriting a minima the alphawiki's parser.

{b 1) stringlisp} is a small interpreter built on a single loop using a regular expression evaluating a sequence of nested s-expressions °°{first rest}°° where first is a built-in name (operator or function) defined in a single dictionary, and rest is a string or an s-expression °°{first rest}°°.
    {b 2) dictionary} :
        HTML : @, div, span, ul, ol, li, dl, dt, dd, table, tr, td, h1, h2, h3, h4, h5, h6, p, br, hr, b, i, u, a, img, sup, sub, del, pre, center, blockquote, code, note, show, and more to come …
        MATH : if, >, <, =, not, or, and, +, *, -, /, %, abs, acos, asin, atan, atan2, ceil, cos, exp, floor, log, max, min, pow, random, round, sin, sqrt, tan, PI, E, serie, map, reduce, lib
    {b 3) notes} :
        the dictionary can be extended using the lambda and def operators, ie :
            define&call : °°{{lambda {:a :b} {sqrt {+ {* :a :a}{* :b :b}}} 3 4}°° -> 5
            defining : °°{def hypo {lambda {:a :b} {sqrt {+ {* :a :a}{* :b :b}}}}°°
            and calling : °°{hypo 3 4}°° -> 5
        function's parameters must be prefixed by an hyphen : x -> :x
        the input operator can be used for inline javascript coding.
        hiding any text is done this way : {sup o}{sup o}{sup o} comment {sup o}{sup o}{sup o}.
        prevent evaluation of s-expressions this way : {sup o}{sup o}{* 1 2 3}{sup o}{sup o} > {* 1 2 3}.
    {b 4) console}
        Any number of valid s-expressions entered in the light yellow red border frame below are evaluated in real-time in the green border frame.
        You can copy/paste examples of s-expressions from the blue frame.
        You may have to type something in the editor to "awake" the interpreter !

The source code contains about 130 JS lines for the evaluator and 160 JS lines for the dictionary, and can be seen in the file [[stringlisp.js|data/stringlisp.js]].

}

_p This page will give a description of the code, focusing on its essential part, the evaluator.