Files
sml-projects/fcore/search/search-line-gap.sml

68 lines
1.8 KiB
Standard ML

structure SearchLineGap =
struct
fun cons (num, acc) =
let
val num = Vector.fromList [num]
in
case acc of
hd :: tl =>
if Vector.length hd < 32 then
(Vector.concat [num, hd]) :: tl
else
num :: acc
| [] => num :: acc
end
fun searchStep (pos, hd, absIdx, tl, acc, searchPos, searchString) =
if searchPos < 0 then
cons (absIdx + 1, acc)
else if pos < 0 then
case tl of
hd :: tl =>
searchStep (String.size hd - 1, hd, absIdx, tl, acc, searchPos, searchString)
| [] => acc
else
let
val bufferChr = String.sub (hd, pos)
val searchChr = String.sub (searchString, searchPos)
in
if bufferChr = searchChr then
searchStep (pos - 1, hd, absIdx - 1, tl, acc, searchPos - 1, searchString)
else
acc
end
fun loopSearch (pos, hd, absIdx, tl, acc, searchString) =
if pos < 0 then
case tl of
hd :: tl =>
loopSearch (String.size hd - 1, hd, absIdx, tl, acc, searchString)
| [] => acc
else
let
val acc = searchStep
(pos, hd, absIdx, tl, acc, String.size searchString - 1, searchString)
in
loopSearch (pos - 1, hd, absIdx - 1, tl, acc, searchString)
end
(* Prerequisite: move buffer/LineGap to end *)
fun search (buffer: LineGap.t, searchString) =
let
val acc =
if String.size searchString = 0 then
[]
else
let
val {leftStrings, idx = absIdx, ...} = buffer
in
case leftStrings of
hd :: tl =>
loopSearch (String.size hd - 1, hd, absIdx - 1, tl, [], searchString)
| [] => []
end
in
{left = [], right = acc}
end
end