Files
handlebars.js/lib/handlebars/vm.js
T

660 lines
18 KiB
JavaScript

var Handlebars = require("handlebars");
// BEGIN(BROWSER)
Handlebars.Compiler = function() {};
Handlebars.JavaScriptCompiler = function() {};
(function(Compiler, JavaScriptCompiler) {
Compiler.OPCODE_MAP = {
appendContent: 1,
getContext: 2,
lookupWithFallback: 3,
lookup: 4,
append: 5,
invokeMustache: 6,
appendEscaped: 7,
pushString: 8,
truthyOrFallback: 9,
functionOrFallback: 10,
invokeProgram: 11,
invokePartial: 12,
push: 13,
invokeInverse: 14
};
Compiler.MULTI_PARAM_OPCODES = {
appendContent: 1,
getContext: 1,
lookupWithFallback: 1,
lookup: 1,
invokeMustache: 2,
pushString: 1,
truthyOrFallback: 1,
functionOrFallback: 1,
invokeProgram: 2,
invokePartial: 1,
push: 1,
invokeInverse: 1
};
Compiler.DISASSEMBLE_MAP = {};
for(var prop in Compiler.OPCODE_MAP) {
var value = Compiler.OPCODE_MAP[prop];
Compiler.DISASSEMBLE_MAP[value] = prop;
}
Compiler.multiParamSize = function(code) {
return Compiler.MULTI_PARAM_OPCODES[Compiler.DISASSEMBLE_MAP[code]];
};
Compiler.prototype = {
disassemble: function() {
var opcodes = this.opcodes, opcode, nextCode;
var out = [], str, name, value;
for(var i=0, l=opcodes.length; i<l; i++) {
opcode = opcodes[i];
if(opcode === 'DECLARE') {
name = opcodes[++i];
value = opcodes[++i];
out.push("DECLARE " + name + " = " + value);
} else {
str = Compiler.DISASSEMBLE_MAP[opcode];
var extraParams = Compiler.multiParamSize(opcode);
var codes = [];
for(var j=0; j<extraParams; j++) {
nextCode = opcodes[++i];
if(typeof nextCode === "string") {
nextCode = "\"" + nextCode.replace("\n", "\\n") + "\"";
}
codes.push(nextCode);
}
str = str + " " + codes.join(" ");
out.push(str);
}
}
return out.join("\n");
},
guid: 0,
compile: function(program) {
this.children = [];
this.depths = {list: []};
return this.program(program);
},
accept: function(node) {
return this[node.type](node);
},
program: function(program) {
var statements = program.statements, statement;
this.opcodes = [];
for(var i=0, l=statements.length; i<l; i++) {
statement = statements[i];
this[statement.type](statement);
}
this.depths.list = this.depths.list.sort(function(a, b) {
return a - b;
});
return this;
},
compileProgram: function(program) {
var result = new Compiler().compile(program);
var guid = this.guid++;
this.usePartial = this.usePartial || result.usePartial;
this.children[guid] = result;
for(var i=0, l=result.depths.list.length; i<l; i++) {
depth = result.depths.list[i];
if(depth < 2) { continue; }
else { this.addDepth(depth - 1); }
}
return guid;
},
block: function(block) {
var mustache = block.mustache;
var params = mustache.params, depth, child, inverse, inverseGuid;
this.pushParams(params);
// ID lookup is now on the stack
this.ID(mustache.id);
var programGuid = this.compileProgram(block.program);
if(block.program.inverse) {
inverseGuid = this.compileProgram(block.program.inverse);
}
if(block.program.inverse) {
this.declare('inverse', inverseGuid);
}
this.opcode('invokeProgram', programGuid, params.length);
this.declare('inverse', null);
this.opcode('append');
},
inverse: function(block) {
this.ID(block.mustache.id);
var programGuid = this.compileProgram(block.program);
this.opcode('invokeInverse', programGuid);
this.opcode('append');
},
partial: function(partial) {
var id = partial.id;
this.usePartial = true;
if(partial.context) {
this.ID(partial.context);
} else {
this.opcode('push', 'context');
}
this.opcode('invokePartial', id.original);
this.opcode('append');
},
content: function(content) {
this.opcode('appendContent', content.string);
},
mustache: function(mustache) {
var params = mustache.params;
this.pushParams(params);
this.ID(mustache.id);
this.opcode('invokeMustache', params.length, mustache.id.original);
if(mustache.escaped) {
this.opcode('appendEscaped');
} else {
this.opcode('append');
}
},
ID: function(id) {
this.addDepth(id.depth);
this.opcode('getContext', id.depth);
this.opcode('lookupWithFallback', id.parts[0] || null);
for(var i=1, l=id.parts.length; i<l; i++) {
this.opcode('lookup', id.parts[i]);
}
},
STRING: function(string) {
this.opcode('pushString', string.string);
},
comment: function() {},
pushParams: function(params) {
var i = params.length, param;
while(i--) {
param = params[i];
this[param.type](param);
}
},
opcode: function(name, val1, val2) {
this.opcodes.push(Compiler.OPCODE_MAP[name]);
if(val1 !== undefined) { this.opcodes.push(val1); }
if(val2 !== undefined) { this.opcodes.push(val2); }
},
declare: function(name, value) {
this.opcodes.push('DECLARE');
this.opcodes.push(name);
this.opcodes.push(value);
},
addDepth: function(depth) {
if(depth === 0) { return; }
if(!this.depths[depth]) {
this.depths[depth] = true;
this.depths.list.push(depth);
}
}
};
JavaScriptCompiler.prototype = {
// PUBLIC API: You can override these methods in a subclass to provide
// alternative compiled forms for name lookup and buffering semantics
nameLookup: function(parent, name, type) {
if(JavaScriptCompiler.RESERVED_WORDS[name]) {
return parent + "['" + name + "']";
} else {
return parent + "." + name;
}
},
appendToBuffer: function(string) {
return "buffer = buffer + " + string + ";";
},
initializeBuffer: function() {
return this.quotedString("");
},
// END PUBLIC API
compile: function(environment, data) {
this.environment = environment;
this.data = data;
this.preamble();
this.stackSlot = 0;
this.stackVars = [];
this.registers = {list: []};
this.compileChildren(environment, data);
Handlebars.log(Handlebars.logger.DEBUG, environment.disassemble() + "\n\n");
var opcodes = environment.opcodes, opcode, name, declareName, declareVal;
this.i = 0;
for(l=opcodes.length; this.i<l; this.i++) {
opcode = this.nextOpcode(0);
if(opcode[0] === 'DECLARE') {
this.i = this.i + 2;
this[opcode[1]] = opcode[2];
} else {
this.i = this.i + opcode[1].length;
this[opcode[0]].apply(this, opcode[1]);
}
}
return this.createFunction();
},
nextOpcode: function(n) {
var opcodes = this.environment.opcodes, opcode = opcodes[this.i + n], name, val;
var extraParams, codes;
if(opcode === 'DECLARE') {
name = opcodes[this.i + 1];
val = opcodes[this.i + 2];
return ['DECLARE', name, val];
} else {
name = Compiler.DISASSEMBLE_MAP[opcode];
extraParams = Compiler.multiParamSize(opcode);
codes = [];
for(var j=0; j<extraParams; j++) {
codes.push(opcodes[this.i + j + 1 + n]);
}
return [name, codes];
}
},
eat: function(opcode) {
this.i = this.i + opcode.length;
},
preamble: function() {
var out = [];
out.push("var buffer = " + this.initializeBuffer() + ", currentContext = context");
var copies = "helpers = helpers || Handlebars.helpers;";
if(this.environment.usePartial) { copies = copies + " partials = partials || Handlebars.partials;"; }
out.push(copies);
// track the last context pushed into place to allow skipping the
// getContext opcode when it would be a noop
this.lastContext = 0;
this.source = out;
},
createFunction: function() {
var container = {
escapeExpression: Handlebars.Utils.escapeExpression,
invokePartial: Handlebars.VM.invokePartial,
programs: [],
program: function(i, helpers, partials, data) {
var programWrapper = this.programs[i];
if(data) {
return Handlebars.VM.program(this.children[i], helpers, partials, data);
} else if(programWrapper) {
return programWrapper;
} else {
programWrapper = this.programs[i] = Handlebars.VM.program(this.children[i], helpers, partials);
return programWrapper;
}
},
programWithDepth: Handlebars.VM.programWithDepth,
noop: Handlebars.VM.noop
};
var locals = this.stackVars.concat(this.registers.list);
if(locals.length > 0) {
this.source[0] = this.source[0] + ", " + locals.join(", ");
}
this.source[0] = this.source[0] + ";";
this.source.push("return buffer;");
var params = ["Handlebars", "context", "helpers", "partials"];
if(this.data) { params.push("data"); }
for(var i=0, l=this.environment.depths.list.length; i<l; i++) {
params.push("depth" + this.environment.depths.list[i]);
}
if(params.length === 4 && !this.environment.usePartial) { params.pop(); }
params.push(this.source.join("\n"));
var fn = Function.apply(this, params);
fn.displayName = "Handlebars.js";
Handlebars.log(Handlebars.logger.DEBUG, fn.toString() + "\n\n");
container.render = fn;
container.children = this.environment.children;
return function(context, helpers, partials, data, $depth) {
try {
var args = Array.prototype.slice.call(arguments);
args.unshift(Handlebars);
return container.render.apply(container, args);
} catch(e) {
throw e;
}
};
},
appendContent: function(content) {
this.source.push(this.appendToBuffer(this.quotedString(content)));
},
append: function() {
var local = this.popStack();
this.source.push("if(" + local + " || " + local + " === 0) { " + this.appendToBuffer(local) + " }");
},
appendEscaped: function() {
var opcode = this.nextOpcode(1), extra = "";
if(opcode[0] === 'appendContent') {
extra = " + " + this.quotedString(opcode[1][0]);
this.eat(opcode);
}
this.source.push(this.appendToBuffer("this.escapeExpression(" + this.popStack() + ")" + extra));
},
getContext: function(depth) {
if(this.lastContext !== depth) {
this.lastContext = depth;
if(depth === 0) {
this.source.push("currentContext = context;");
} else {
this.source.push("currentContext = depth" + depth + ";");
}
}
},
lookupWithFallback: function(name) {
if(name) {
this.pushStack(this.nameLookup('currentContext', name, 'context'));
var topStack = this.topStack();
this.source.push("if(" + topStack + " === undefined) { " + topStack + " = " + this.nameLookup('helpers', name, 'helper') + "; }");
} else {
this.pushStack("currentContext");
}
},
lookup: function(name) {
var topStack = this.topStack();
this.source.push(topStack + " = " + this.nameLookup(topStack, name, 'context') + ";");
},
pushString: function(string) {
this.pushStack(this.quotedString(string));
},
push: function(name) {
this.pushStack(name);
},
invokeMustache: function(paramSize, original) {
var params = ["context"], fn, slot;
fn = this.popStack();
for(var i=0; i<paramSize; i++) {
params.push(this.popStack());
}
if(this.data) { params.push("data"); }
var paramString = params.join(", ");
var helperMissing = ["context"].concat(this.quotedString(original)).concat(params.slice(1));
slot = this.nextStack();
if(paramSize === 0) {
// TODO: This case is not listed in the mustache spec. Is it important?
this.source.push("if(typeof " + fn + " === 'function') { " + slot + " = " + fn + ".call(" + paramString + "); }");
} else {
this.source.push("if(typeof " + fn + " === 'function') { " + slot + " = " + fn + ".call(" + paramString + "); } else { " + slot + " = helpers.helperMissing.call(" + helperMissing + ") }");
}
},
invokeProgram: function(guid, paramSize) {
var inverse = this.programExpression(this.inverse);
var fn = this.popStack();
var id = fn;
var params = ["context"];
var blockMissingParams = ["context", id];
for(var i=0; i<paramSize; i++) {
var param = this.popStack();
params.push(param);
blockMissingParams.push(param);
}
var mainProgram = this.programExpression(guid);
params.push(mainProgram, inverse);
blockMissingParams.push(mainProgram, inverse);
if(this.data) {
params.push("data");
blockMissingParams.push("data");
}
var nextStack = this.nextStack();
this.source.push("if(typeof " + id + " === 'function') { " + nextStack + " = " + id + ".call(" + params.join(", ") + "); }");
this.source.push("else { " + nextStack + " = helpers.blockHelperMissing.call(" + blockMissingParams.join(", ") + "); }");
},
invokeInverse: function(guid) {
var program = this.programExpression(guid);
var blockMissingParams = ["context", this.topStack(), "this.noop", program];
this.pushStack("helpers.blockHelperMissing.call(" + blockMissingParams.join(", ") + ")");
},
invokePartial: function(context) {
this.pushStack("this.invokePartial(" + this.nameLookup('partials', context, 'partial') + ", '" + context + "', " + this.popStack() + ", helpers, partials);");
},
// HELPERS
compiler: JavaScriptCompiler,
compileChildren: function(environment, data) {
var children = environment.children, child, compiler;
var compiled = [];
for(var i=0, l=children.length; i<l; i++) {
child = children[i];
compiler = new this.compiler();
compiled[i] = compiler.compile(child, data);
}
environment.rawChildren = children;
environment.children = compiled;
},
programExpression: function(guid) {
if(guid == null) { return "this.noop"; }
var programParams = [guid, "helpers", "partials"];
var depths = this.environment.rawChildren[guid].depths.list;
if(this.data) { programParams.push("data"); }
for(var i=0, l = depths.length; i<l; i++) {
depth = depths[i];
if(depth === 1) { programParams.push("context"); }
else { programParams.push("depth" + (depth - 1)); }
}
if(!this.environment.usePartial) {
if(programParams[3]) {
programParams[2] = "null";
} else {
programParams.pop();
}
}
if(depths.length === 0) {
return "this.program(" + programParams.join(", ") + ")";
} else {
programParams[0] = "this.children[" + guid + "]";
return "this.programWithDepth(" + programParams.join(", ") + ")";
}
},
register: function(name, val) {
this.useRegister(name);
this.source.push(name + " = " + val + ";");
},
useRegister: function(name) {
if(!this.registers[name]) {
this.registers[name] = true;
this.registers.list.push(name);
}
},
pushStack: function(item) {
this.source.push(this.nextStack() + " = " + item + ";");
return "stack" + this.stackSlot;
},
nextStack: function() {
this.stackSlot++;
if(this.stackSlot > this.stackVars.length) { this.stackVars.push("stack" + this.stackSlot); }
return "stack" + this.stackSlot;
},
popStack: function() {
return "stack" + this.stackSlot--;
},
topStack: function() {
return "stack" + this.stackSlot;
},
quotedString: function(str) {
return '"' + str
.replace(/\\/, '\\\\')
.replace(/"/g, '\\"')
.replace(/\n/g, '\\n')
.replace(/\r/g, '\\r') + '"';
}
};
var reservedWords = ("break case catch continue default delete do else finally " +
"for function if in instanceof new return switch this throw " +
"try typeof var void while with null true false").split(" ");
compilerWords = JavaScriptCompiler.RESERVED_WORDS = {};
for(var i=0, l=reservedWords.length; i<l; i++) {
compilerWords[reservedWords[i]] = true;
}
})(Handlebars.Compiler, Handlebars.JavaScriptCompiler);
Handlebars.VM = {
programWithDepth: function(fn) {
var args = Array.prototype.slice.call(arguments, 1);
return function(context) {
return fn.apply(this, [context].concat(args));
};
},
program: function(fn, helpers, partials, data) {
return function(context) {
return fn(context, helpers, partials, data);
};
},
noop: function() { return ""; },
compile: function(string, data) {
var ast = Handlebars.parse(string);
var environment = new Handlebars.Compiler().compile(ast);
return new Handlebars.JavaScriptCompiler().compile(environment, data);
},
invokePartial: function(partial, name, context, helpers, partials) {
if(partial === undefined) {
throw new Handlebars.Exception("The partial " + name + " could not be found");
} else if(partial instanceof Function) {
return partial(context, helpers, partials);
} else {
partials[name] = Handlebars.VM.compile(partial);
return partials[name](context, helpers, partials);
}
}
};
Handlebars.compile = Handlebars.VM.compile;
// END(BROWSER)