doc/tutorial/basics/6_expressions/50_fieldcomp.txt

cue eval -c fieldcomp.cue
cmp stdout expect-stdout-cue

-- frontmatter.toml --
title = "Field Comprehensions"
description = ""

-- text.md --
CUE also supports comprehensions for fields.

One cannot refer to generated fields with references.
Instead, one must use indexing.

-- fieldcomp.cue --
import "strings"

#a: [ "Barcelona", "Shanghai", "Munich" ]

for k, v in #a {
    "\( strings.ToLower(v) )": {
        pos:     k + 1
        name:    v
        nameLen: len(v)
    }
}

-- expect-stdout-cue --
barcelona: {
    name:    "Barcelona"
    pos:     1
    nameLen: 9
}
shanghai: {
    name:    "Shanghai"
    pos:     2
    nameLen: 8
}
munich: {
    name:    "Munich"
    pos:     3
    nameLen: 6
}