I want to be able to say: * field = a, b, c for fields which can take an array.

• modifier[0] = #missing
• modifier[1] = #text
• modifier[2] = #not
• modifier[3] = #in
• modifier[4] = #not-in
• modifier[5] = #below
• modifier[6] = #above
• modifier[7] = #ofType

Should allow me to say:
measure = #missing, #text, #not, #in, #not-in, #below, #above, #ofType

Proposed Wording:

https://github.com/FHIR/sushi/blob/master/antlr/src/main/antlr/FSH.g4