In my words, build a tool that can trace the source of a variable's data, for every data variables in the source code. Lay them down in a timeline. Easy if it i

In my words, build a tool that can trace the source of a variable's data, for every data variables in the source code. Lay them down in a timeline. Easy if it is single threaded language. Flatten the branches. Applications 1. minification. 2. cross programming language code generation. 3. Source tracing complements control flow tracing. Bringing in AST based solution will complicate the problem. What do you think ?