Package gnu.expr

Class PushApply

java.lang.Object
gnu.expr.ExpVisitor<Expression,Void>
gnu.expr.PushApply
All Implemented Interfaces:
SourceLocator, SourceLocator, Locator
public class PushApply extends ExpVisitor<Expression,Void>
Re-arranges ApplyExp where the function is a LetExp or BeginExp. Optimizes ((let (...) body) . args) to (let (...) (body . args)). Optimizes ((begin ... last) . args) to (begin ... (last . args)). This helps optimize Scheme "named let" (and some other forms) by making it more likely the application will be to a known procedure. Optimizes (if (let (...) body) e1 [e2]) to (let (...) (if body e1 [e2])). Optimizes (if (begin ... last) e1 [e2]) to (begin ... (if last e1 [e2])). These optimizations have to be done after Declarations are bound. Also, for each LambdaExp set the canFinishCondition field. This information is used in the following InlineCalls pass, to determine which calls (and thus other expressions) have the type neverReturnsType. That in turn is used in the later ChainLambda pass to warn about unreachable code.