Coercion of complex literals

[hatyo]

It should be possible to coerce multiple complex types to find a common maximum type they can all be instances of (with / without promotion), this can get complicated considering the absence of an attribute of a complex type is permissible when the value is null.

For example, assume the user defines an array of complex literals like the following:

[ {X = 42, Y = 5.0, Z = 'bla'}, {X = 50.0, Y = 4.3}, {W = 'a'} ]

The maximum type that all of the above instances can be mapped to requires visiting all of the instances to figure that out.

Struct <> {
   X float;
   Y float;
   Z string;
   W string;
}

we could do this by calculating the maximum type via:

fdb-record-layer/fdb-record-layer-core/src/main/java/com/apple/foundationdb/record/query/plan/cascades/typing/Type.java

Line 525 in 98d988c

static Type maximumType(@Nonnull final Type t1, @Nonnull final Type t2) {

maximumType(
    maximumType(
          ToCascadesType("{X = 42, Y = 5.0, Z = 'bla'}"),
          ToCascadesType("{X = 50.0, Y = 4.3}"),
     ToCascadesType("{W = 'a'}"))

But this requires adding the capability of calculating the maximum type of a structured type to Type.maximumType which we do not have at the moment.