comparison: lvm.js
lvm.js
- changeset 0
- 2fcdf7f16d71
- child 1
- f32a9c1be7c6
equal
deleted
inserted
replaced
| -1:000000000000 | 0:2fcdf7f16d71 |
|---|---|
| 1 | |
| 2 var OP_LOADK = 1; | |
| 3 var OP_GETGLOBAL = 5; | |
| 4 var OP_CALL = 28; | |
| 5 | |
| 6 function LValue(type, value) | |
| 7 { | |
| 8 this.type = type||"nil"; | |
| 9 this.value = value||null; | |
| 10 } | |
| 11 | |
| 12 LValue.prototype = { | |
| 13 call: function (args) | |
| 14 { | |
| 15 if(typeof(this.value) == "function") | |
| 16 { | |
| 17 return this.value.apply(null, args.map(function (a) { return a.value; })); | |
| 18 } | |
| 19 }, | |
| 20 index: function (key) | |
| 21 { | |
| 22 if(this.type == "table") | |
| 23 { | |
| 24 return this.value[key.value]; | |
| 25 } | |
| 26 }, | |
| 27 setIndex: function (key, value) | |
| 28 { | |
| 29 if(this.type == "table") | |
| 30 { | |
| 31 this.value[key.value] = value; | |
| 32 } | |
| 33 } | |
| 34 }; | |
| 35 | |
| 36 function LValueFromString(string) | |
| 37 { | |
| 38 return new LValue("string", string); | |
| 39 } | |
| 40 | |
| 41 function LValueFromFunction(func) | |
| 42 { | |
| 43 return new LValue("function", func); | |
| 44 } | |
| 45 | |
| 46 var default_environment = new LValue("table", {}); | |
| 47 | |
| 48 var print; | |
| 49 if(typeof(document) == "object") | |
| 50 print = function (a) { document.write(a+"<br/>") }; | |
| 51 else | |
| 52 { | |
| 53 // Assume running under Nodejs | |
| 54 print = require("sys").puts; | |
| 55 } | |
| 56 default_environment.setIndex(LValueFromString("print"), LValueFromFunction(print)); | |
| 57 | |
| 58 function LFunction() | |
| 59 { | |
| 60 this.constants = []; | |
| 61 this.instructions = []; | |
| 62 this.environment = default_environment; | |
| 63 return this; | |
| 64 } | |
| 65 | |
| 66 LFunction.prototype = { | |
| 67 addInstruction: function (instruction) | |
| 68 { | |
| 69 this.instructions.push(instruction); | |
| 70 }, | |
| 71 addConstant: function (constant) | |
| 72 { | |
| 73 this.constants.push(constant); | |
| 74 } | |
| 75 }; | |
| 76 | |
| 77 function LVM() | |
| 78 { | |
| 79 this.callstack = []; | |
| 80 this.stack = []; | |
| 81 return this; | |
| 82 } | |
| 83 | |
| 84 LVM.prototype = { | |
| 85 run: function (lfFunction) | |
| 86 { | |
| 87 this.currentFrame = {f:lfFunction,pc:0}; | |
| 88 this.callstack.push(this.currentFrame); | |
| 89 var instruction; | |
| 90 while(this.callstack.length>0) | |
| 91 { | |
| 92 instruction = this.currentFrame.f.instructions[this.currentFrame.pc++]; | |
| 93 if(!instruction) | |
| 94 break; | |
| 95 switch(instruction[0]) | |
| 96 { | |
| 97 case OP_GETGLOBAL: | |
| 98 var name = this.currentFrame.f.constants[instruction[2]]; | |
| 99 this.stack[instruction[1]] = this.currentFrame.f.environment.index(name); | |
| 100 break; | |
| 101 case OP_LOADK: | |
| 102 var value = this.currentFrame.f.constants[instruction[2]]; | |
| 103 this.stack[instruction[1]] = value; | |
| 104 break; | |
| 105 case OP_CALL: | |
| 106 var f = this.stack[instruction[1]]; | |
| 107 f.call(this.stack.splice(instruction[1]+1, instruction[1]+(instruction[2]-1))); | |
| 108 break; | |
| 109 case OP_RETURN: | |
| 110 this.callstack.pop(); | |
| 111 break; | |
| 112 default: | |
| 113 } | |
| 114 } | |
| 115 } | |
| 116 }; | |
| 117 | |
| 118 var testvm = new LVM(); | |
| 119 var mycode = new LFunction(); | |
| 120 mycode.addConstant(LValueFromString("print")); | |
| 121 mycode.addConstant(LValueFromString("Hello world")); | |
| 122 mycode.addInstruction([OP_GETGLOBAL, 0, 0]); | |
| 123 mycode.addInstruction([OP_LOADK, 1, 1]); | |
| 124 mycode.addInstruction([OP_CALL, 0, 2, 1]); | |
| 125 testvm.run(mycode); |
