YuMingLiao

hi @agentm Does that mean we need something like [this code](https://gist.github.com/nebuta/6096345)?

Oh, sorry I wasn't clear about my question. I was trying to understand what you mean about separating AST and ADT. Did you mean right now the relational expression is...

Option1 sounds better for long term to me too. From what I can understand, relational algebra ADT is for just relational expression. And a new tutd-specific ADT can express more,...

Oh, I just realized that `data TutdExpr = ... | With RelationalExpr RelationalExpr | ...` alone can't solve the problem. `evalRelationalExpr` still needs to pass relation variable mapping around.

`With` macro feels like something similar with #52. What if we add relation variable mapping in RelationalExprStateElems (something I haven't got it through)? What's long term gain of option1 over...

I've made a first pass, using the relation expression state. I use `AS` instead of `:=` at a first pass just try to help me implement it from SQL WITH....

I am facing similar issue after I successfully compiled a module with template haskell ($embedFile) in it. Now another module can't find it. I don't know what's causing that, either....

Maybe it is related to this [issue](https://github.com/commercialhaskell/stack/issues/2903). Maybe adding an extension TemplateHaskell can fix this.

After I try to add TemplateHaskell in lib and main in package.nix, the problem still exists.

I have simplified my yesod code to [this](https://github.com/YuMingLiao/issue-setting-object-file). And it's the `staticFiles (...)` line that makes the "`Settings` object file missing" error appear. I'll look into it tomorrow.