Post Issue #75, the email parsing backend will be configurable via a command line flag or configuration option. For this issue, define a combinator that can take in two email parsing backends and output a new email parsing backend that implements alternative logic---i.e. the logic of the (<|>) operator from Haskell.
The logic of A <|> B is, roughly:
try A
if it succeeds, move on
if it fails, try B
Broadly speaking, this could most likely become a module functor that would take two modules of signature PARSETREE and output a new module with the same signature as the output of Conversion.Make, which implements the above logic for two email parsing backends A and B. Another option might be to implement an alternative module functor for PARSETREE modules, i.e. one whose return signature is also PARSETREE.
Post Issue #75, the email parsing backend will be configurable via a command line flag or configuration option. For this issue, define a combinator that can take in two email parsing backends and output a new email parsing backend that implements alternative logic---i.e. the logic of the
(<|>)operator from Haskell.The logic of
A <|> Bis, roughly:Broadly speaking, this could most likely become a module functor that would take two modules of signature
PARSETREEand output a new module with the same signature as the output ofConversion.Make, which implements the above logic for two email parsing backendsAandB. Another option might be to implement an alternative module functor forPARSETREEmodules, i.e. one whose return signature is alsoPARSETREE.