com.twitter.summingbird.planner.DagOptimizer
If the given Id can be replaced with a simpler expression, return Some(expr) else None.
If the given Id can be replaced with a simpler expression, return Some(expr) else None.
If it is convenient, you might write a partial function and then call .lift to get the correct Function type
Strip all the names. Names are rightly considered as names on the irreducible parts of the input graph (functions, stores, sinks, sources, etc...) and not the AST that we generate and optimize along the way