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| (Empty) |
| 1 part of lisp; | |
| 2 | |
| 3 /** | |
| 4 * The native functions. | |
| 5 */ | |
| 6 class Natives { | |
| 7 | |
| 8 /** Imports the native functions into the [environment]. */ | |
| 9 static Environment import(Environment environment) { | |
| 10 | |
| 11 // basic functions | |
| 12 environment.define(new Name('define'), _define); | |
| 13 environment.define(new Name('lambda'), _lambda); | |
| 14 environment.define(new Name('quote'), _quote); | |
| 15 environment.define(new Name('eval'), _eval); | |
| 16 environment.define(new Name('apply'), _apply); | |
| 17 environment.define(new Name('let'), _let); | |
| 18 environment.define(new Name('set!'), _set); | |
| 19 environment.define(new Name('print'), _print); | |
| 20 | |
| 21 // control structures | |
| 22 environment.define(new Name('if'), _if); | |
| 23 environment.define(new Name('while'), _while); | |
| 24 environment.define(new Name('and'), _and); | |
| 25 environment.define(new Name('or'), _or); | |
| 26 environment.define(new Name('not'), _not); | |
| 27 | |
| 28 // arithmetic operators | |
| 29 environment.define(new Name('+'), _plus); | |
| 30 environment.define(new Name('-'), _minus); | |
| 31 environment.define(new Name('*'), _multiply); | |
| 32 environment.define(new Name('/'), _divide); | |
| 33 environment.define(new Name('%'), _modulo); | |
| 34 | |
| 35 // arithmetic comparators | |
| 36 environment.define(new Name('<'), _smaller); | |
| 37 environment.define(new Name('<='), _smallerOrEqual); | |
| 38 environment.define(new Name('='), _equal); | |
| 39 environment.define(new Name('!='), _notEqual); | |
| 40 environment.define(new Name('>'), _larger); | |
| 41 environment.define(new Name('>='), _largerOrEqual); | |
| 42 | |
| 43 // list operators | |
| 44 environment.define(new Name('cons'), _cons); | |
| 45 environment.define(new Name('car'), _car); | |
| 46 environment.define(new Name('car!'), _carSet); | |
| 47 environment.define(new Name('cdr'), _cdr); | |
| 48 environment.define(new Name('cdr!'), _cdrSet); | |
| 49 | |
| 50 return environment; | |
| 51 } | |
| 52 | |
| 53 static _define(Environment env, args) { | |
| 54 if (args.head is Name) { | |
| 55 return env.define(args.head, evalList(env, args.tail)); | |
| 56 } else if (args.head.head is Name) { | |
| 57 return env.define( | |
| 58 args.head.head, _lambda(env, new Cons(args.head.tail, args.tail))); | |
| 59 } else { | |
| 60 throw new ArgumentError('Invalid define: $args'); | |
| 61 } | |
| 62 } | |
| 63 | |
| 64 static _lambda(Environment lambda_env, lambda_args) { | |
| 65 return (Environment env, args) { | |
| 66 var inner = lambda_env.create(); | |
| 67 var names = lambda_args.head; | |
| 68 var values = evalArguments(env, args); | |
| 69 while (names != null && values != null) { | |
| 70 inner.define(names.head, values.head); | |
| 71 names = names.tail; | |
| 72 values = values.tail; | |
| 73 } | |
| 74 return evalList(inner, lambda_args.tail); | |
| 75 }; | |
| 76 } | |
| 77 | |
| 78 static _quote(Environment env, args) { | |
| 79 return args; | |
| 80 } | |
| 81 | |
| 82 static _eval(Environment env, args) { | |
| 83 return eval(env.create(), eval(env, args.head)); | |
| 84 } | |
| 85 | |
| 86 static _apply(Environment env, args) { | |
| 87 return eval(env, args.head)(env.create(), args.tail); | |
| 88 } | |
| 89 | |
| 90 static _let(Environment env, args) { | |
| 91 var inner = env.create(); | |
| 92 var binding = args.head; | |
| 93 while (binding != null) { | |
| 94 inner.define(binding.head.head, eval(env, binding.head.tail.head)); | |
| 95 binding = binding.tail; | |
| 96 } | |
| 97 return evalList(inner, args.tail); | |
| 98 } | |
| 99 | |
| 100 static _set(Environment env, args) { | |
| 101 return env[args.head] = eval(env, args.tail.head); | |
| 102 } | |
| 103 | |
| 104 static _print(Environment env, args) { | |
| 105 var buffer = new StringBuffer(); | |
| 106 while (args != null) { | |
| 107 buffer.write(eval(env, args.head)); | |
| 108 args = args.tail; | |
| 109 } | |
| 110 print(buffer); | |
| 111 return null; | |
| 112 } | |
| 113 | |
| 114 static _if(Environment env, args) { | |
| 115 var condition = eval(env, args.head); | |
| 116 if (condition) { | |
| 117 if (args.tail != null) { | |
| 118 return eval(env, args.tail.head); | |
| 119 } | |
| 120 } else { | |
| 121 if (args.tail != null && args.tail.tail != null) { | |
| 122 return eval(env, args.tail.tail.head); | |
| 123 } | |
| 124 } | |
| 125 return null; | |
| 126 } | |
| 127 | |
| 128 static _while(Environment env, args) { | |
| 129 var result = null; | |
| 130 while (eval(env, args.head)) { | |
| 131 result = evalList(env, args.tail); | |
| 132 } | |
| 133 return result; | |
| 134 } | |
| 135 | |
| 136 static _and(Environment env, args) { | |
| 137 while (args != null) { | |
| 138 if (!eval(env, args.head)) { | |
| 139 return false; | |
| 140 } | |
| 141 args = args.tail; | |
| 142 } | |
| 143 return true; | |
| 144 } | |
| 145 | |
| 146 static _or(Environment env, args) { | |
| 147 while (args != null) { | |
| 148 if (eval(env, args.head)) { | |
| 149 return true; | |
| 150 } | |
| 151 args = args.tail; | |
| 152 } | |
| 153 return false; | |
| 154 } | |
| 155 | |
| 156 static _not(Environment env, args) { | |
| 157 return !eval(env, args.head); | |
| 158 } | |
| 159 | |
| 160 static _plus(Environment env, args) { | |
| 161 var value = eval(env, args.head); | |
| 162 for (args = args.tail; args != null; args = args.tail) { | |
| 163 value += eval(env, args.head); | |
| 164 } | |
| 165 return value; | |
| 166 } | |
| 167 | |
| 168 static _minus(Environment env, args) { | |
| 169 var value = eval(env, args.head); | |
| 170 if (args.tail == null) { | |
| 171 return -value; | |
| 172 } | |
| 173 for (args = args.tail; args != null; args = args.tail) { | |
| 174 value -= eval(env, args.head); | |
| 175 } | |
| 176 return value; | |
| 177 } | |
| 178 | |
| 179 static _multiply(Environment env, args) { | |
| 180 var value = eval(env, args.head); | |
| 181 for (args = args.tail; args != null; args = args.tail) { | |
| 182 value *= eval(env, args.head); | |
| 183 } | |
| 184 return value; | |
| 185 } | |
| 186 | |
| 187 static _divide(Environment env, args) { | |
| 188 var value = eval(env, args.head); | |
| 189 for (args = args.tail; args != null; args = args.tail) { | |
| 190 value /= eval(env, args.head); | |
| 191 } | |
| 192 return value; | |
| 193 } | |
| 194 | |
| 195 static _modulo(Environment env, args) { | |
| 196 var value = eval(env, args.head); | |
| 197 for (args = args.tail; args != null; args = args.tail) { | |
| 198 value %= eval(env, args.head); | |
| 199 } | |
| 200 return value; | |
| 201 } | |
| 202 | |
| 203 static _smaller(Environment env, args) { | |
| 204 return eval(env, args.head) < eval(env, args.tail.head); | |
| 205 } | |
| 206 | |
| 207 static _smallerOrEqual(Environment env, args) { | |
| 208 return eval(env, args.head) <= eval(env, args.tail.head); | |
| 209 } | |
| 210 | |
| 211 static _equal(Environment env, args) { | |
| 212 return eval(env, args.head) == eval(env, args.tail.head); | |
| 213 } | |
| 214 | |
| 215 static _notEqual(Environment env, args) { | |
| 216 return eval(env, args.head) != eval(env, args.tail.head); | |
| 217 } | |
| 218 | |
| 219 static _larger(Environment env, args) { | |
| 220 return eval(env, args.head) > eval(env, args.tail.head); | |
| 221 } | |
| 222 | |
| 223 static _largerOrEqual(Environment env, args) { | |
| 224 return eval(env, args.head) >= eval(env, args.tail.head); | |
| 225 } | |
| 226 | |
| 227 static _cons(Environment env, args) { | |
| 228 return new Cons(eval(env, args.head), eval(env, args.tail.head)); | |
| 229 } | |
| 230 | |
| 231 static _car(Environment env, args) { | |
| 232 var cons = eval(env, args.head); | |
| 233 return cons is Cons ? cons.head : null; | |
| 234 } | |
| 235 | |
| 236 static _carSet(Environment env, args) { | |
| 237 var cons = eval(env, args.head); | |
| 238 if (cons is Cons) { | |
| 239 cons.head = eval(env, args.tail.head); | |
| 240 } | |
| 241 return cons; | |
| 242 } | |
| 243 | |
| 244 static _cdr(Environment env, args) { | |
| 245 var cons = eval(env, args.head); | |
| 246 return cons is Cons ? cons.tail : null; | |
| 247 } | |
| 248 | |
| 249 static _cdrSet(Environment env, args) { | |
| 250 var cons = eval(env, args.head); | |
| 251 if (cons is Cons) { | |
| 252 cons.tail = eval(env, args.tail.head); | |
| 253 } | |
| 254 return cons; | |
| 255 } | |
| 256 } | |
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Chromium Code Reviews
Issue 1400473008:
Roll Observatory packages and add a roll script (Closed)
Base URL: git@github.com:dart-lang/observatory_pub_packages.git@master