Interpolation of optional fields

[eonpatapon]

Let say I have a few fields to interpolate in a string (some are optionals, some are not), my current solution is:

import "strings"

a: "foo"
b?: string

let R = strings.Join([
  a,
  if b != _|_ { b },
], "\n")
result: """
  stuff
  \(R)
  other stuff
"""

So the question is: is there a more simple way to do this ?

[verdverm]

Not sure if this is simpler, but another option is to use the text/template package instead of interpolation. I generally prefer text/template when

• the data is mildly complex
• the content starts getting long enough
• you want conditional content based on the values
• you want to loop over data

(self plug) https://github.com/hofstadter-io/hof is a tool for when you want to generate many files from a schema defined in Cue.

[mpvl]

If a and b were in a separate struct, you could use a comprehension to iterate over them. This will skip optional fields.

Also some of the proposed constructs in the query proposal will help here.

[eonpatapon]

If a and b were in a separate struct, you could use a comprehension to iterate over them. This will skip optional fields.

Oh cool I didn't know that! Thanks

[seh]

This will skip optional fields.

Do you mean optional but non-concrete fields? Would it skip a populated value for b?

[mpvl]

When unified with a non-optional field, it will still iterate over it, even when not concrete.

[cueckoo]

This discussion has been migrated to cue-lang/cue#807.

For more details about CUE's migration to a new home, please see cue-lang/cue#1078.