85 lines
2.5 KiB
Standard ML
85 lines
2.5 KiB
Standard ML
signature MAKE_DFA_LOOP =
|
|
sig
|
|
val fStart: int * int * string * string list * Word8.word * int -> int
|
|
val startState: Word8.word
|
|
end
|
|
|
|
functor MakeNextDfaLoop(M: MAKE_DFA_LOOP) =
|
|
struct
|
|
fun next (lineGap: LineGap.t, cursorIdx) =
|
|
let
|
|
val {rightStrings, idx = bufferIdx, ...} = lineGap
|
|
in
|
|
case rightStrings of
|
|
shd :: stl =>
|
|
let
|
|
(* convert absolute cursorIdx to idx relative to hd string *)
|
|
val strIdx = cursorIdx - bufferIdx
|
|
in
|
|
if strIdx < String.size shd then
|
|
(* strIdx is in this string *)
|
|
M.fStart (strIdx, cursorIdx, shd, stl, M.startState, 1)
|
|
else
|
|
(* strIdx is in tl *)
|
|
case stl of
|
|
stlhd :: stltl =>
|
|
M.fStart (strIdx, cursorIdx, stlhd, stltl, M.startState, 1)
|
|
| _ => cursorIdx
|
|
end
|
|
| [] => cursorIdx
|
|
end
|
|
end
|
|
|
|
functor MakePrevDfaLoop(M: MAKE_DFA_LOOP) =
|
|
struct
|
|
fun prev (lineGap: LineGap.t, cursorIdx) =
|
|
let
|
|
val {rightStrings, leftStrings, idx = bufferIdx, ...} = lineGap
|
|
in
|
|
case rightStrings of
|
|
shd :: stl =>
|
|
let
|
|
(* convert absolute cursorIdx to idx relative to hd string *)
|
|
val strIdx = cursorIdx - bufferIdx
|
|
in
|
|
if strIdx < String.size shd then
|
|
(* strIdx is in this string *)
|
|
M.fStart (strIdx, cursorIdx, shd, leftStrings, M.startState, 1)
|
|
else
|
|
(* strIdx is in tl *)
|
|
(case stl of
|
|
stlhd :: stltl =>
|
|
let
|
|
val strIdx = strIdx - String.size shd
|
|
val leftStrings = shd :: leftStrings
|
|
in
|
|
M.fStart
|
|
(strIdx, cursorIdx, stlhd, leftStrings, M.startState, 1)
|
|
end
|
|
| [] => cursorIdx)
|
|
end
|
|
| [] => cursorIdx
|
|
end
|
|
end
|
|
|
|
functor MakePrevDfaLoopMinus1(M: MAKE_DFA_LOOP) =
|
|
struct
|
|
fun prev (lineGap: LineGap.t, cursorIdx) =
|
|
let
|
|
val {idx = bufferIdx, leftStrings, ...} = lineGap
|
|
val strIdx = cursorIdx - bufferIdx - 1
|
|
val absIdx = cursorIdx - 1
|
|
in
|
|
if strIdx < 0 then
|
|
case leftStrings of
|
|
lhd :: ltl =>
|
|
M.fStart (String.size lhd - 1, absIdx, lhd, ltl, M.startState, 1)
|
|
| [] => 0
|
|
else
|
|
case #rightStrings lineGap of
|
|
rhd :: _ =>
|
|
M.fStart (strIdx, absIdx, rhd, leftStrings, M.startState, 1)
|
|
| [] => Int.max (0, cursorIdx - 2)
|
|
end
|
|
end
|