lambdaway :: kernel

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_h1 [[concepts]] | kernel

_p The {b act I} in the page [[concepts]], supposed to be at the λ-calculus level, introduces a few lambda expressions, like

{pre
((lambda (:a :b) 
         My name is :b, :a :b.)
        James Bond)
-> {eval ((lambda (:a :b) My name is :b, :a :b.) James Bond)}

((lambda (:c) (:c 
  (lambda (:a :b) :a))) 
  ((lambda (:a :b :c) (:c :a :b)) 
    James Bond))
-> {eval ((lambda (:c) (:c 
  (lambda (:a :b) :a))) 
  ((lambda (:a :b :c) (:c :a :b)) 
    James Bond))}
}

_p The first one is preferably splitted like this

{pre
(def HI (lambda (:a :b) My name is :b, :a :b.))
-> {eval (def HI (lambda (:a :b) My name is :b, :a :b.))}

(HI James Bond)
-> {eval (HI James Bond)}
(HI Antoine de Saint Exupery)
-> {eval (HI Antoine de Saint Exupery)}
}

_p and the second one like this

{pre
(def PAIR (lambda (:a :b :c) (:c :a :b)))
-> {eval (def PAIR (lambda (:a :b :c) (:c :a :b)))}
(def LEFT (lambda (:c) (:c (lambda (:a :b) :a))))
-> {eval (def LEFT (lambda (:c) (:c (lambda (:a :b) :a))))}
(def RIGHT (lambda (:c) (:c (lambda (:a :b) :b))))
-> {eval (def RIGHT (lambda (:c) (:c (lambda (:a :b) :b))))}

(def JB (PAIR James Bond))
-> {eval (def JB (PAIR James Bond))}
(LEFT (JB))
-> {eval (LEFT (JB))}
(RIGHT (JB)) 
-> {eval (RIGHT (JB))}

}

_h2 here is the JS code

_p Evaluations are made thanks to this minimal javascript code

{pre °°
var KERNEL = (function() {
  var regexp = /\(([^\s()]*)(?:[\s]*)([^()]*)\)/g,
        DICT = {}, LAMB_num = 0;

var evaluate = function(s) {
    s = eval_specials(s,'lambda',eval_lambda);
    s = eval_specials(s,'def',eval_def,true); 
    s = eval_forms(s);
    return s
  };

var eval_forms = function(s) { 
    while (s !== (s = s.replace(regexp, eval_form)));
    return s;
  };

var eval_form = function() {
    var f = arguments[1] || "", r = arguments[2] || "";
    return DICT.hasOwnProperty(f) ? 
      DICT[f].apply(null, [r]) : 
      "«‚" + f + " " + r + "»";
  };

var eval_specials = function(s,symbol,eval_symbol,flag) {
    while (s !== (s = form_replace(s,symbol,eval_symbol,flag))) ;
    return s; 
  };

var form_replace = function(str, symbol, func, flag) {
    symbol = "(" + symbol + " ";
    var s = catch_form(symbol, str);
    return s === "none" ? str : str.replace(symbol + s + ")", func(s, flag));
  };

var catch_form = function(symbol, str) {
    var start = str.indexOf(symbol);
    if (start == -1) return "none";
    var d1 = symbol.length,
        nb = 1, 
     index = start;
    while (nb > 0) {
      index++;
      if (str.charAt(index) == "(") nb++;
      else if (str.charAt(index) == ")") nb--;
    }
    return str.substring(start + d1, index);
  };

return { evaluate:evaluate }

})(); // end of KERNEL

// interface with lambdatalk:

LAMBDATALK.DICT['eval'] = function() {
  var args = arguments[0].trim();
  return KERNEL.evaluate( args )
};

°°}

_p This code is extracted from the [[lambdatalk's JS code|meca/JS.js]], reduced to the evaluation of nested forms {b (a (b (c ... word)))} and two special forms, {b lambda & def}, working in a dictionary initially empty. Note that to avoid conflicts in this page, round braces replace the standard curly braces used in lambdatalk.

_p {i am | 2023/02/16}

_h2 le même compressé avec [[https://jscompress.com/|https://jscompress.com/]]

{prewrap °°
var KERNEL=function(){var r=/\(([^\s()]*)(?:[\s]*)([^()]*)\)/g,a={},t=0,g=function(n){for(;n!==(n=n.replace(r,e)););return n},e=function(){var n=arguments[1]||"",r=arguments[2]||"";return a.hasOwnProperty(n)?a[n].apply(null,[r]):"«‚"+n+" "+r+"»"},f=function(n,r,e,t){for(;n!==(n=u(n,r,e,t)););return n},s=function(n){var r=n.indexOf(")"),e=n.substring(1,r),i=""===e?[]:e.split(" "),l=n.substring(r+2),r="_LAMB_"+t++,l=f(l,"lambda",s);return a[r]=function(){var n=arguments[0],r=""===n?[]:n.split(" "),e=l;if(r.length< i.length){for(var t=0;t< r.length;t++)e=e.replace(RegExp(i[t],"g"),r[t]);n=i.slice(r.length).join(" "),e=s("("+n+") "+e)}else if(r.length===i.length)for(t=0;t< i.length;t++)e=e.replace(RegExp(i[t],"g"),r[t]);else{var u=r.slice(0,i.length);u[i.length-1]=r.slice(i.length-1,r.length).join(" ");for(t=0;t< i.length;t++)e=e.replace(RegExp(i[t],"g"),u[t])}return g(e)},r},i=function(n,r){var e=(n=f(n,"def",i,!1)).search(/\s/),t=n.substring(0,e).trim(),u=n.substring(e).trim();return"_LAMB_"===u.substring(0,6)?a[t]=a[u]:(u=g(u),a[t]=function(){return u}),r?t:""},u=function(n,r,e,t){var u=l(r="("+r+" ",n);return"none"===u?n:n.replace(r+u+")",e(u,t))},l=function(n,r){var e=r.indexOf(n);if(-1==e)return"none";for(var n=n.length,t=1,u=e;0< t;)u++,"("==r.charAt(u)?t++:")"==r.charAt(u)&&t--;return r.substring(e+n,u)};return{evaluate:function(n){return n=f(n,"lambda",s),n=f(n,"def",i,!0),n=g(n)}}}();LAMBDATALK.DICT.eval=function(){var n=arguments[0].trim();return KERNEL.evaluate(n)};
°°}

{script 
var KERNEL = (function() {
  var regexp = /\(([^\s()]*)(?:[\s]*)([^()]*)\)/g,
        DICT = {}, LAMB_num = 0;

var evaluate = function(s) {
    s = eval_specials(s,'lambda',eval_lambda);
    s = eval_specials(s,'def',eval_def,true);
    s = eval_forms(s);
    return s
  };

var eval_forms = function(s) { 
    while (s !== (s = s.replace(regexp, eval_form)));
    return s;
  };

var eval_form = function() {
    var f = arguments[1] || "", r = arguments[2] || "";
    return DICT.hasOwnProperty(f) ? DICT[f].apply(null, [r]) : "«‚" + f + " " + r + "»";
  };

var eval_specials = function(s,symbol,eval_symbol,flag) {
    while (s !== (s = form_replace(s, symbol, eval_symbol, flag))) ;
    return s; 
  };

return {
    evaluate: evaluate,
    DICT:DICT 
  };

})(); // end of KERNEL

LAMBDATALK.DICT['eval'] = function() {  // ((lambda (:a :b) :b :a) james bond)
  var args = arguments[0].trim();
  return KERNEL.evaluate( args )
};

}