α-wwwiki

α-wwwiki :: history/psil/20130619-182448.txt

editor : alpha [82.253.220.49] 2013/06/19 18:24:48
_h1 psil
_p I just discover on Github a [[smart pocket lisp interpreter|https://gist.github.com/pabloPXL/1679611]] written by [[Pablo Vidal|https://github.com/pabloPXL]].

{pre {@ id="output"}}
{input {@ type="submit" value="Click on me !" onclick="°°

// start dictionary / global environment
function env(){
  var inst  = this;
  inst.atom = function(a){ return atomp(a) };
  inst.set  = function(as){ return inst[as[0]] = as[1] };
  inst.quote = function(as){ return as[0] };
  inst.fst  = function(as){ return as[0][0] };
  inst.rst  = function(as){ return as[0].slice(1) };
  inst.cons = function(as){ return [as[0]].concat(as[1]) };
  inst.eq   = function(as){ return as[0] === as[1] };
  inst.cond = function(as,cx){ 
    return evaluate(as[0],cx) ? 
      evaluate(as[1],cx) : 
      evaluate(as[2],cx) 
  };

inst['++'] = function(as){ as[0] = as[0] + 1; return as[0] };
  inst['--'] = function(as){ as[0] = as[0] - 1; return as[0] };
  inst['*'] = function(as){ 
    for (var i=0, p=1; i< as.length; i++) p *= as[i];
    return p;
  };

var mathfns = 
  ['abs', 'acos', 'asin', 'atan', 'atan2', 'ceil', 'cos', 'exp', 
  'floor', 'log', 'max', 'min', 'random', 'round', 'sin', 'sqrt', 'tan'];
  for (var i=0; i< mathfns.length; i++)
    inst[mathfns[i]] = function( tag ) { 
      return function (as) { return Math[tag](as[0]) } 
    }(mathfns[i]);

return inst;
}
// end dictionary / global environment

// start parser
function extended_cx( ar, cx ){
  var foo = function(o, kv){ 
  	o[ kv[0] ] = kv[1]; 
  	return o; 
  };
  return ar.reduce( foo, cx || {} );
}
function zip( ar1, ar2 ){
  var foo = function(ar, v1, i1){ 
  	if (ar2[i1]) 
  		ar.push( [v1,ar2[i1]] ); 
  	return ar; 
  };
  return ar1.reduce( foo, [] );
}
function atomp( a ){ 
  return !(typeof a in {object:0,array:0}) 
}
function lazyp( a ){ 
  return (a in {cond:0,quote:0,lambda:0}) 
}
function apply( rf, as, cx ){
  return rf in cx && cx[rf].call ? 
    cx[rf].call(null, as, cx) : 
    evaluate( cx[rf][2], extended_cx( zip( cx[rf][1], as ), cx ) );
}
function evaluate( sx, cx ){
  if (atomp(sx))
    return sx in cx ? cx[sx] : sx;
  var rf = sx[0];
  var foo = function( a ){ 
  	return lazyp(rf) ? a : evaluate(a, cx); 
  };
  var as = sx.slice(1).map( foo);
  return apply(rf, as, cx);
}
// end parser

// start test
function psil () {
  var cx = new env;
  var str = ''
+ '\n[set,a,42] -> ' + evaluate(['set','a',42],cx)
+ '\na -> ' + evaluate('a',cx)
+ '\n[eq,42,a] -> ' + evaluate(['eq',42,'a'],cx)
+ '\n[quote,[1,2]] -> ' + evaluate(['quote',[1,2]],cx)
+ '\n[fst,[quote,[1,2]]] -> ' + evaluate(['fst',['quote',[1,2]]],cx)
+ '\n[rst,[quote,[1,2]]] -> ' + evaluate(['rst',['quote',[1,2]]],cx)
+ '\n[cons,1,[quote,[2,3]]] -> ' + evaluate(['cons',1,['quote',[2,3]]],cx)
+ '\n[cond,[eq,1,2],42,43] -> ' + evaluate(['cond',['eq',1,2],42,43],cx)
+ '\n[atom,[quote,[1,2]]] -> ' + evaluate(['atom',['quote',[1,2]]],cx)
+ '\n[set,second,[quote,[lambda,[x],[fst,[rst,x]]]]] -> ' 
+ evaluate(['set','second',['quote',['lambda',['x'],['fst',['rst','x']]]]],cx)
+ '\n[second,[quote,[1,2,3]]] -> ' + evaluate(['second',['quote',[1,2,3]]],cx)
+ '\n'
+ '\n[set,y,10] -> ' + evaluate(['set','y',10],cx)
+ '\n[set,z,11] -> ' + evaluate(['set','z',11],cx)
+ '\n[cond,[eq,y,z],true,false] -> ' + evaluate(['cond',['eq','y','z'],true,false],cx)
+ '\n[++,10] -> ' + evaluate(['++',10],cx)
+ '\n[--,10] -> ' + evaluate(['--',10],cx)
+ '\n[*,1,2,3,4,5,6] -> ' + evaluate(['*',1,2,3,4,5,6],cx)
+ '\n[set,cubic,[quote,[lambda,[x],[*,x,x,x]]]] -> ' 
+ evaluate( ['set','cubic',['quote',['lambda',['x'],['*','x','x','x']]]],cx)
+ '\n[cubic,4] -> ' + evaluate(['cubic',4],cx)
+ '\n[sqrt,2] -> ' + evaluate(['sqrt',2],cx)
+ '\n[exp,1] -> ' + evaluate(['exp',1],cx)

+ '\n'
+ '\nbut factorial : '
+ '\n[set,fac,[quote,[lambda,[x],[cond,[eq,x,0],1,[*,[x],[fac,[--,x]]]]]]]'

+ '\n' + evaluate( 
  ['set','fac',
    ['quote',
      ['lambda',['x'], 
        ['cond', 
          ['eq','x',0],
            1, 
            ['*', 
            ['x'], 
            ['fac', ['--','x'] ]       
          ]    
        ]       
      ]
    ]
  ]
  ,cx) 
  
+ '\n[fac,6] -> TypeError: ar1 is undefined ?'  // + evaluate(['fac',6],cx)

+ '\n'
+ '\nHTML should works if it was allowed in the wiki context ;'
+ '\nsomething to fix outside this test-console.'
+ '\n[h1,titre]' 
+ '\n[p,A paragraph with a,[b,bold,[u,underlined,[i,italicized word]]]]' 
+ '\n -> '
+ '\n' + evaluate(['h1','titre'],cx)
+ '\n' + evaluate(['p','A paragraph with a',['b','bold',['u','underlined',['i','italicized word']]]],cx)

return str;
}

getId('output').innerHTML = psil();
°°"}}
_p A lot to learn. Recursive functions, partial/currying, etc ...