23 lines
903 B
OCaml
23 lines
903 B
OCaml
type t = { text : string; pos : int; right_boundary : int }
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let overran cursor = cursor.pos >= cursor.right_boundary
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let next_char cursor = { cursor with pos = cursor.pos + 1 }
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let char_at cur offset = String.get cur.text (cur.pos + offset)
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let char cur = String.get cur.text cur.pos
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let distance a b = b.pos - a.pos
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let sub ?left ?right cur = { cur with
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pos = Option.value left ~default:cur.pos;
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right_boundary = Option.value right ~default:cur.right_boundary }
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let unwrap num cur = sub ~left:(cur.pos+num) ~right:(cur.right_boundary-num) cur
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let segment_string cur = String.sub cur.text cur.pos (cur.right_boundary - cur.pos)
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(*todo: reconsider +1 result and type cursor*)
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let rec find_end e = function
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| cur when cur.pos + 1 = String.length cur.text -> Some cur.pos
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| cur when overran cur -> None
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| cur when e cur (char cur) -> Some (cur.pos + 1)
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| cur -> find_end e (next_char cur)
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