36 lines
785 B
OCaml
36 lines
785 B
OCaml
open import "prelude.ml"
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class pretty 'a begin
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val pretty : 'a -> int -> string
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end
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type prettyable =
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| S : show 'a => 'a -> prettyable
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| P : pretty 'a => 'a -> prettyable
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let render_prettyable x w =
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match x with
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| S a -> show a
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| P a -> pretty a w
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class prettyrecord 'r begin
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val name : 'r -> string
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val fields : 'r -> list (string * prettyable)
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end
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let pretty_from_record a w =
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let rec smul s n =
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if n <= 0 then
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""
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else
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s ^ (smul s (n - 1))
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let x = w + 2
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let prep = smul " " w
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let rf = fields a
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let render_field (name, field) =
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name ^ " = " ^ (render_prettyable field x)
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let field_str =
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foldl (fun acc f -> acc ^ prep ^ " " ^ (render_field f) ^ ",\n") ""
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let body = field_str rf
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(name a) ^ " {\n" ^ body ^ prep ^ "}"
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