heredocs.red

s: {^/  2^/  2^/   3}
heredoc2: function [str [ string!] ][
  str: remove copy str
  number-of-spaces-in-line: spaces: 0 ; initialize in order not to leak by parse
  lines: split str "^/"
  indentation: 99999999
  foreach line lines [
    parse line [copy spaces any space (number-of-spaces-in-line: length? spaces)  to end]
    if indentation > number-of-spaces-in-line [
      indentation: number-of-spaces-in-line
    ]
  ]
  new-str: copy ""
  foreach line lines [
    append new-str remove/part line indentation
    append new-str "^/"
  ] 
  new-str
]

heredoc1: function [str [string! ] ] [
  spaces copy ""
  str: remove copy str
  indentation: 0
  lines: split str "^/"
  chars: charset [#"0" - #"9" #"a" - #"z"]
  parse str [copy spaces to  chars to end]
  indentation: length? spaces
  new-str: copy ""
  foreach line lines [
    append new-str remove/part line indentation
    append new-str "^/"
  ]
  new-str
]
print s
print heredoc1 s
print heredoc2 s