Module `Beloch.Diagnostic`

Render a Beloch_error as a rustc-style source-context block, with the hint as a help line under the caret when there is one. Pure: source text + span + message + hint -> string. Uses whatever span the error carries.

val render : 
  source:string ->
  span:Error.span ->
  msg:string ->
  hint:string option ->
  string