sweetjs's resolveCtx rewritten recursively

resolveCtx.js

// (Syntax) -> String
function resolveCtx(originalName, ctx, stop_spine, stop_branch) {
    if (ctx instanceof Mark) {
        return resolveCtx(originalName, ctx.context, stop_spine, stop_branch);
    }
    if (ctx instanceof Def) {
        if (stop_spine.indexOf(ctx.defctx) !== -1) {
            return resolveCtx(originalName, ctx.context, stop_spine, stop_branch);
        }
        return resolveCtx(originalName, renames(ctx.defctx, ctx.context, originalName), stop_spine, unionEl(stop_branch, ctx.defctx));
    }
    if (ctx instanceof Rename) {
        if (originalName === ctx.id.token.value) {
            var idName  = resolveCtx(ctx.id.token.value, ctx.id.context, stop_branch, stop_branch);
            var subName = resolveCtx(originalName, ctx.context, unionEl(stop_spine, ctx.def), stop_branch);
            if (idName === subName) {
                var idMarks  = marksof(ctx.id.context, originalName + "$" + ctx.name, originalName);
                var subMarks = marksof(ctx.context, originalName + "$" + ctx.name, originalName);
                if (arraysEqual(idMarks, subMarks)) {
                    return originalName + "$" + ctx.name;
                }
            }
        }
        return resolveCtx(originalName, ctx.context, stop_spine, stop_branch);
    }
    return originalName;
}