The current parser will fail parsing floats because it parses an int,
and then stumbles on the dot.
To fix I interpret the value with the scientific library which already
is a dependency through attoparsec, so we're not introducing any extra
downloads or compiling.
I think this is still subtly wrong because "10.0" will be parsed as
ValueInt, but because input argument ints are allowed to be coerced
into doubles (according to the spec) this is probably acceptable.
The `Schema` has been overhauled to make `Output` monomorphic.
Traversing the `GraphQL` document is handled implicitly while defining
the `Schema`.
The 4th end-to-end test from `graphql-js` has been ported.
The first end-to-end test taken from `graphql-js` passes but this still
needs to be extended to support more general cases.
- `Data.GraphQL.Schema` has been heavily modified to support the
execution model. More drastic changes are expected in this module.
- When defining a `Schema` ordinary functions taking fields as input are
being used instead of maps. This makes the implementation of `execute`
easier, and, arguably, makes `Schema` definitions more *Haskellish*.
- Drop explicit `unordered-containers` dependency. `Aeson.Value`s and
field functions should be good enough for now.
WIP: This parser just type checks, it hasn't even been tested manually.
Check new tasks in the TODO file and the TODO comments in the code for
more gotchas.
