as.vector doesn't work on categorical array expression

[gergness]

Also would be nice if it worked on a VarDef because that's what we get from deriveArray().

Will make sense to work on this when we figure out the derived subvariable metadata that is currently blocking #453

library(crunch)
login()

ds <- newDataset(
    data.frame(x1 = letters[1:2], x2 = letters[1:2]),
    name = "as.vector derived arrays issue"
)

as.vector(
    crunch:::CrunchExpr(
        expression = deriveArray(
            list(VarDef(ds$x1 == "a", name = "x1_a"), VarDef(ds$x2 == "a", name = "x2_a")), 
            name = "derived array"
        )$derivation, 
        dataset_url = self(ds), 
        filter= list()
    )
)

#>  Error in (function (classes, fdef, mtable)  : 
#>    unable to find an inherited method for function ‘tuple’ for signature ‘"VariableEntity"’ 

[gergness]

Also in as.vector, would be nice if we could get it to work for Subvariables.

ds$x <-  deriveArray(list(VarDef(ds$x1 == "a", name = "x1_a"), VarDef(ds$x2 == "a", name = "x2_a")), name = "derived array")

as.vector(ds$x["x1_a"])
#> Error in as.vector(ds$x["x1_a"]) : 
#>  no method for coercing this S4 class to a vector

class(ds$x["x1_a"])
#> [1] "Subvariables"
#> attr(,"package")
#> [1] "crunch"

[malecki]

no longer blocking expression-based addSubvariable, so need for this is diminished; also, as.vector that gave you a bunch of vectors doesn’t seem quite the right fit either. Will need to see if related needs come up again elsewhere.