hoot

1 2 /* 3 4 This is the compressor which is used to reduce the size of the game 'build' 5 output considerably. The tool compresses the game build, and a minified copy 6 of everything here *except* hootCompress() is in examplegame.html so that the 7 game can be decompressed before it is played. 8 9 NOTE: examplegame.html copy minified with UglifyJS (at jscompress.com) 10 11 12 13 The dictionary compression approach is very fast and quite effective. 14 Results of a small sample script are: 15 16 Game source: 2169 17 Game: 2606 (-20% vs src) 18 Compressed: 1620 (25% vs src, 38% vs 'orig' build) 19 Decompressed same?: true 20 21 */ 22 23 24 // minification starts here... 25 26 27 // The Compression Dictionary - see comments below about its creation 28 // ----------------------------------------------------------------------------- 29 var dict = ["\"],[\"break\",\"__\"],[\"string\",\"", "[[\"script\",[\"func\",[\"name\",\"", "\"],[\"print\",[\"string\",\"", "\"]]],[\"func\",[\"name\",\"", "\"],[\"break\",\"__\"]", "[\"func\",[\"name\",\"", "\"],[\"string\",\"", " \"],[\"link\",\"", ",[\"string\",\"", "\"],[\"link\",\"", "\",[\"name\",\"", "[[\"script\"", " of the ", " through", "start", " of the", " of th", " that ", " with ", " your ", ". The ", "n the ", " and ", " are ", " for ", " the ", " The ", " with", " you ", " You ", ". The", "\"],[\"", "]],[\"", "h you", "ight ", "n the", "s the", "s you", " and", " are", " for", " in ", " is ", " of ", " the", " The", " to ", " whe", " you", " You", ". Th", "\"]]]", "],[\"", "and ", "e th", "hat ", "ight", "ing ", "ion ", "ith ", "k\",\"", "me\",", "n th", "our ", "r po", "s of", "s th", "t th", "ter ", "The ", "You ", " a ", " A ", " an", " ar", " as", " be", " bo", " ca", " co", " di", " do", " dr", " fo", " fr", " ha", " he", " in", " is", " it", " li", " ma", " mi", " no", " of", " on", " pa", " po", " re", " ro", " se", " st", " th", " Th", " to", " wa", " wh", " wi", " wo", "'s ", ",[\"", ". ", ". T", "\",\"", "\"]]", "]]]", "ain", "al ", "all", "and", "ant", "ard", "are", "as ", "at ", "ate", "ce ", "ch ", "ck ", "cke", "d b", "d t", "d. ", "e a", "e b", "e c", "e f", "e i", "e o", "e p", "e r", "e s", "e t", "e w", "e. ", "ead", "ear", "eat", "ed ", "en ", "ent", "er ", "ere", "ers", "es ", "est", "f t", "for", "fun", "ght", "hat", "he ", "her", "hin", "his", "igh", "ill", "in ", "ine", "ing", "int", "ion", "is ", "ite", "ith", "ive", "ke ", "le ", "ll ", "ly ", "n t", "nd ", "ne ", "ng ", "nt ", "o t", "of ", "on ", "one", "or ", "ou ", "oun", "our", "ow ", "per", "pla", "r t", "r. ", "rd ", "re ", "rea", "res", "s a", "s o", "s t", "s. ", "se ", "st ", "t a", "t l", "t o", "t t", "t. ", "te ", "ter", "th ", "the", "The", "thi", "to ", "ts ", "tur", "und", "ur ", "ure", "use", "ut ", "ve ", "ver", "wit", "wor", "y a", "You", "you", "run", "\"]", "\\", "\""]; 30 // ----------------------------------------------------------------------------- 31 32 // currently this allows for 300-something dictionary entries - the above list is 235 33 var hootCompressionCode = []; 34 for(var i=164; i<167; i++){ // ¤¥¦ 35 for(var j=35; j<127; j++){ 36 if(j==92){ continue; } // the backslash will cause string trouble! 37 hootCompressionCode.push(String.fromCharCode(i,j)); 38 } 39 } 40 41 function rot13(script){ // http://stackoverflow.com/a/5353260/695615 42 return script.replace(/[a-zA-Z]/g, function(c) { 43 return String.fromCharCode((c <= 'Z' ? 90 : 122) >= (c = c.charCodeAt(0) + 13) ? c : c - 26); 44 }); 45 } 46 47 48 49 50 // ============================================================================= 51 // The decompressor will be minified and included with the examplegame.html 52 // page, along with a minified copy of the dictionary, code table, and rot13. 53 // ============================================================================= 54 55 function hootDecompress(script){ 56 script = rot13(script); 57 for(var i=dict.length-1; i>=0; i--){ // see note below about reverse order 58 // we can't use replace() because it only replaces globaly with 59 // regular expressions - and we definitely can't use our dictionary 60 // entries as regular expressions (and if they were modified so that 61 // we could, they would not be reversible back to the original strings!) 62 script = script.split(hootCompressionCode[i]).join(dict[i]); 63 } 64 return script; 65 } 66 67 68 // ...and ends here 69 70 71 // ============================================================================= 72 // The compressor is called directly from here by hoot-builder.js when building 73 // the game output. 74 // ============================================================================= 75 function hootCompress(script){ 76 for(d in dict){ 77 // see note above about why we can't just use replace 78 script = script.split(dict[d]).join(hootCompressionCode[d]); 79 } 80 return rot13(script); 81 } 82 83 84 85 86 /* 87 88 A note about the decompression running through the dictionary on reverse order 89 when deompressing: 90 91 It's completely possible for a replacement to match the results of a previous 92 replacement, totally corrupting the output. For example, given these two 93 replacements: 94 95 replace 'oo' with '$ee' 96 replace 'ee ba' with '$xx' 97 98 Now imagine the string "foo bar fee bar" being replaced with these two replacements. 99 It would be corrupted if we were to undo the replacements in the same order, but 100 completely fine if we undid the replacements in the reverse order. 101 102 103 104 A note about the dictionary. 105 106 The common strings were created using hoot-create-dictionary.html 107 to extract commonly-used strings from some representative text. Namely: 108 109 Some sample Hootscript games produced these common strings: 110 Settings: 111 var max_likely_string_len = 100; 112 var min_string_len = 3; 113 var min_frequency = 5; 114 -------------------------------------------------------------------------------- 115 ",[\"", "\",\"", "],[\"", "ing", " you", "tri", ",[\"string\",\"", "the", "ou ", " the", "he ", " of", " a ", "k\",\"", " to", " of ", "\"],[\"string\",\"", "nd ", " the ", " your ", "to ", "and", " to ", " an", "re ", "e t", "rea", "]]]", " you ", "int", "and ", "me\",", "You", " and ", " po", "\",[\"name\",\"", "\"],[\"link\",\"", "\"]]", "fun", "ed ", "You ", "\"],[\"print\",[\"string\",\"", "\"]]]", ",[\"func\",[\"name\",\"", "e a", "er ", " be", "ing ", "]],[\"", ". ", "y a", "ve ", "\"]", "\"],[\"string\",\"", "ith", "t a", "e w", "\"]]],[\"func\",[\"name\",\"", "e th", " ar", " li", " \"],[\"link\",\"", "her", "\"],[\"", "ight", "ter", "at ", "e o", "on ", " co", "\"],[\"break\",\"__\"]", "st ", "cke", "th ", "for", "ead", " are", " se", "ll ", "h you", "s t", "r t", "t o", "f t", "ate", "ere", "one", " through", "\"],[\"break\",\"__\"],[\"string\",\"", "s you", "r po", "is ", "ight ", "pla", "t l", ", you", "ain", "e s", "or ", " are ", " whe", " wo", " with ", " that ", " You ", " pa", "ly " 116 -------------------------------------------------------------------------------- 117 118 119 A massaged copy of the Return to Zork script produced these common strings: 120 Settings: 121 var max_likely_string_len = 10; 122 var min_string_len = 3; 123 var min_frequency = 30; 124 -------------------------------------------------------------------------------- 125 "he ", " th", "the", " the", " the ", "ing", " of", " ", "of ", " of ", "ng ", "ed ", "ing ", " Th", " to", "nd ", "The", " The", "to ", "er ", " in", "re ", "The ", " The ", "ou ", " to ", " an", "is ", "at ", " a ", "and", "in ", "es ", " ", ". T", "st ", " you", "ll ", "th ", " You", "s. ", "and ", " wi", "on ", "en ", "e t", " be", "ter", " in ", " and", " and ", ". ", "e. ", "s t", "n t", " is", " fo", ". Th", "or ", " is ", " You ", " re", " ma", "d t", "ts ", " ha", "ck ", "her", "e o", "hat", "e a", "le ", "for", " on", "ion", "all", "f t", " of th", ". The", "ve ", " st", " of the", "n th", " wa", " co", "as ", "ow ", "se ", " of the ", "t t", "ith", "ent", "ut ", "ly ", "ver", " for", "ere", "hat ", "e i", "ers", "n the", " you ", "our", "ill", "ate", ". The ", " ca", "s o", "tur", "ce ", "s a", "e s", "ear", "wit", " with", "ith ", "e b", "n the ", "d. ", "res", "und", "e w", " wh", "oun", "t a", "ite", "e r", "rd ", " with ", " no", "e f", "t. ", "ard", "s th", "eat", "are", "al ", "ch ", " bo", " A ", "ine", "use", " ", "ur ", "his", " fr", " do", "our ", "te ", "igh", "ive", "hin", "wor", "est", "e p", "nt ", "d b", "ght", " it", " ar", "e th", "ne ", "r. ", "ure", " as", " di", " mi", "s the", "t th", "thi", "e c", "ead", "ke ", "per", "'s ", " , ", "o t", "s of", "t o", "ter ", "ant", " dr", " he", "ight", "ion ", " for ", " ro", " Ca", "ound", "ock", "are ", "ar ", "rea", " Mo", " Tr", " In", "ope", "om ", "e of", "an ", "der", "ood", "out", "ste", "s the ", "tha", "ave", "d th", "rin", " Sh", "ore", "ome", "s of ", "to t", "e d", "eve", "rou", "r t", "rs ", "ry ", "han", " pr", " pl", " so", " mo", "ous", ... 126 -------------------------------------------------------------------------------- 127 128 */ 129