run with -> $deno map-test.js | prettier --parser css > output.css

map-test.js

const listMapper = (list, template) => list.map(template).join('\n')
const objectMapper = (object, template) => Object.entries(object).map(template).join('\n')

console.log(
  listMapper(
    [
      'red',
      'blue',
      'green'
    ],
    value => `
      .list-${value} {
        color: ${value};
      }
    `
  )
  + objectMapper(
    {
      red: '#c00',
      green: '#0c0',
      blue: '#00c'
    },
    ([name, value]) => `
      .object-${name} {
        color: ${value};
      }
    `
  )
)

outout.css

.list-red {
  color: red;
}

.list-blue {
  color: blue;
}

.list-green {
  color: green;
}

.object-red {
  color: #c00;
}

.object-green {
  color: #0c0;
}

.object-blue {
  color: #00c;
}