I recently delved into the intricacies of a JavaScript package compiler and decided to revamp its fundamental structure. Each time a string is compiled, it gets appended to the SrcTable array and then outputted. However, for the output to be obtained, the SrcTable must be declared global. This poses a question as the example that serves as the foundation for my code has this variable declared locally.
I am keen on understanding:
1. Why is it not possible to declare the variable locally here?
2. What alterations are necessary to enable it to function as local?
The srcTable resides within the preprocessors.compiler variable.
function resolveRequest(request) {
var match = request.match(/^\s*import\s+(.*)$/),
imports = {};
if (match) {
match[1].replace(/\s*([\w.\-$]+)(?:\s+as\s+([\w.\-$]+))?,?/g, function(_, from, as) {
imports = {
from: from,
as: as || from
};
});
}
return imports;
}
var preprocessors = {
import: "var importExpr = /^(\\s*)(import\\s+[^=+*\"'\\r\\n;\\/]+|from\\s+[^=+\"'\\r\\n;\\/ ]+\\s+import\\s+[^=+\"'\\r\\n;\\/]+)(;|\\/|$)/gm;" +
"function replace(raw, p1, p2, p3) {" +
" return p1 + 'jsio(\"' + p2 + '\")' + p3;" +
"};" +
"exports = function(src) {" +
" return src.replace(importExpr, replace);" +
"};",
compiler: "srcTable = [];" + // inquiring if this array can be made local
" exports = function (src) {" +
" var jsioNormal = " + /^(.*)jsio\s*\(\s*(['"].+?['"])\s*(,\s*\{[^}]+\})?\)/gm + "\n;" +
" var match = jsioNormal.exec(src);\n" +
" if(match) {" +
" var request = eval(match[2]);\n" +
" jsio(request, ['import', 'compiler']);\n" +
" } \n" +
" srcTable.push(src);"+
" return '';\n" +
" };" +
" exports.compile = function(request) {" +
" jsio(request, ['import', 'compiler']);" +
" };" +
" exports.generateSrc = function (callback) {"+
" callback(srcTable);"+
" };"
};
function _require(previousCtx, request, p) {
var p = p || ['import'];
var request = resolveRequest(request);
var src = eval(request.from);
p.forEach(function(name, index) {
var args = name == 'import' ? [] : null;
var preprocessor = jsio('import preprocessors.' + name, args);
src = preprocessor(src);
});
var code = "(function (__) { with (__) {" + src + "}});";
var fn = eval(code);
var context = makeContext();
fn(context);
previousCtx[request.as] = context.exports;
return context.exports;
}
function makeContext() {
return {
jsio: function(request, p) {
return _require(this, request, p);
},
exports: {}
};
}
var jsio = makeContext().jsio;
var example = {
app: "import example.calculator as calculator;" +
" calculator.add(2, 3);",
calculator: "import example.print as print;" +
" exports = {" +
" add: function (a, b) {" +
" print(a+b);" +
" }" +
" }",
print: "exports = function(res) {" +
" console.log(res);" +
" }"
};
var compiler = jsio('import preprocessors.compiler;');
compiler.compile('import example.app;');
compiler.generateSrc(function(src) {
console.log(src);
});