functorise some additional functions to reduce boilerplate
This commit is contained in:
652
fcore/cursor.sml
652
fcore/cursor.sml
@@ -153,91 +153,74 @@ struct
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cursorIdx
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end
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fun helpViH (strIdx, hd, cursorIdx, leftStrings) =
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if strIdx > 0 then
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(* bounds check: can access prev char in hd *)
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if String.sub (hd, strIdx - 1) = #"\n" then
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(* prev char is line break *)
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if strIdx - 1 > 0 then
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(* bounds check: can access two chars back in hd *)
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if String.sub (hd, strIdx - 2) = #"\n" then
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(* line break followed by line break
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* so it is fine to decrement by 1 *)
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cursorIdx - 1
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else
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(* non-line break followed by line break
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* so we have to decrement by two,
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* skipping over line break *)
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cursorIdx - 2
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else
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(* need to check two chars back in leftStrings *)
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(case leftStrings of
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lhd :: ltl =>
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if String.sub (lhd, String.size lhd - 1) = #"\n" then
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(* double line break *)
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cursorIdx - 1
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structure ViH =
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MakeIfCharFolderPrev
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(struct
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fun helpViH (strIdx, hd, cursorIdx, leftStrings) =
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if strIdx > 0 then
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(* bounds check: can access prev char in hd *)
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if String.sub (hd, strIdx - 1) = #"\n" then
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(* prev char is line break *)
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if strIdx - 1 > 0 then
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(* bounds check: can access two chars back in hd *)
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if String.sub (hd, strIdx - 2) = #"\n" then
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(* line break followed by line break
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* so it is fine to decrement by 1 *)
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cursorIdx - 1
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else
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(* non-line break followed by line break
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* so we have to decrement by two,
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* skipping over line break *)
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cursorIdx - 2
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else
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(* non-line break precedes line break *)
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cursorIdx - 2
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| [] => cursorIdx - 1)
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else
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(* prev char is not line break so we can decrement by 1 *)
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cursorIdx - 1
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else
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(* prev char is in leftStrings *)
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(case leftStrings of
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lhd :: ltl =>
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if String.sub (lhd, String.size lhd - 1) = #"\n" then
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(* one line break *)
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if String.size lhd > 1 then
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(* bounds check: prev-prev chr is in lhd *)
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if String.sub (lhd, String.size lhd - 2) = #"\n" then
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(* double line break *)
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cursorIdx - 1
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else
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(* non-line break precedes line break *)
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cursorIdx - 2
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(* need to check two chars back in leftStrings *)
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(case leftStrings of
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lhd :: ltl =>
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if String.sub (lhd, String.size lhd - 1) = #"\n" then
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(* double line break *)
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cursorIdx - 1
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else
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(* non-line break precedes line break *)
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cursorIdx - 2
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| [] => cursorIdx - 1)
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else
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(* prev-prev chr is in ltl *)
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(case ltl of
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ltlhd :: _ =>
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if String.sub (ltlhd, String.size ltlhd - 1) = #"\n" then
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(* double line break *)
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cursorIdx - 1
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else
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(* non-line break precedes line break *)
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cursorIdx - 2
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| [] => cursorIdx - 1)
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(* prev char is not line break so we can decrement by 1 *)
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cursorIdx - 1
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else
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(* no line break *)
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cursorIdx - 1
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| [] => 0)
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(* prev char is in leftStrings *)
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(case leftStrings of
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lhd :: ltl =>
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if String.sub (lhd, String.size lhd - 1) = #"\n" then
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(* one line break *)
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if String.size lhd > 1 then
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(* bounds check: prev-prev chr is in lhd *)
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if String.sub (lhd, String.size lhd - 2) = #"\n" then
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(* double line break *)
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cursorIdx - 1
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else
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(* non-line break precedes line break *)
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cursorIdx - 2
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else
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(* prev-prev chr is in ltl *)
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(case ltl of
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ltlhd :: _ =>
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if String.sub (ltlhd, String.size ltlhd - 1) = #"\n" then
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(* double line break *)
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cursorIdx - 1
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else
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(* non-line break precedes line break *)
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cursorIdx - 2
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| [] => cursorIdx - 1)
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else
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(* no line break *)
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cursorIdx - 1
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| [] => 0)
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(* Prerequisite: lineGap is moved to requested idx first. *)
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fun viH (lineGap: LineGap.t, cursorIdx) =
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let
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val {rightStrings, leftStrings, idx = bufferIdx, ...} = lineGap
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in
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case rightStrings of
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hd :: tl =>
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let
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(* convert absolute cursorIdx to idx relative to hd string *)
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val strIdx = cursorIdx - bufferIdx
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in
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if strIdx < String.size hd then
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(* strIdx in hd *)
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helpViH (strIdx, hd, cursorIdx, leftStrings)
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else
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(* strIdx in tl *)
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(case tl of
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tlhd :: tltl =>
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let val strIdx = strIdx - String.size hd
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in helpViH (strIdx, tlhd, cursorIdx, hd :: leftStrings)
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end
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| [] => cursorIdx)
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end
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| [] => cursorIdx
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end
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fun fStart (strIdx, hd, _, cursorIdx, leftStrings, _) =
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helpViH (strIdx, hd, cursorIdx, leftStrings)
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end)
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val viH = ViH.foldPrev
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fun helpGetCursorColumn (distanceFromLine, strList, lineList) =
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case (strList, lineList) of
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@@ -452,230 +435,215 @@ struct
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| (_, _) => (* nowhere to go rightward, so return cursorIdx *) cursorIdx
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end
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fun helpViK
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( strPos
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, str
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, absIdx
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, lineColumn
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, preferredColumn
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, hasPassedLine
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, strTl
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, lineHd
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, lineTl
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) =
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if strPos < 0 then
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case (strTl, lineTl) of
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(shd :: stl, lhd :: ltl) =>
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helpViK
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( String.size shd - 1
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, shd
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, absIdx
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, lineColumn
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, preferredColumn
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, hasPassedLine
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, stl
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, lhd
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, ltl
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)
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| (_, _) => (* empty, so return start of previous string *) absIdx + 1
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else
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case String.sub (str, strPos) of
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#"\n" =>
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if hasPassedLine then
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(* reached line break twice,
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* but line has fewer chars than preferredColumn
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* so go back to chr immediately after this second line break *)
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absIdx + 1
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else
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(* reached start of line once;
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* have to check if this is a double linebreak,
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* and return idx of second linebreak if so *)
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let
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(* have to calculate column of current line
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* so we know which line to stop searching at *)
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val lineColumn = getCursorColumn
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(strPos - 1, str, lineHd, strTl, lineTl, absIdx - 1)
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in
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helpViK
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( strPos - 1
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, str
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, absIdx - 1
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, lineColumn
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, preferredColumn
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, true
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, strTl
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, lineHd
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, lineTl
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)
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end
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| _ =>
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if lineColumn <= preferredColumn andalso hasPassedLine then
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(* We're at or before the preferredColumn so return absIdx
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* context: current line may have fewer columns
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* than our preferred column value.
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* If this is the case, we want to check
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* "is lineColumn equal to or before preferredColumn?". *)
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absIdx
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else
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(* we're not in the preferred column, so keep iterating *)
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helpViK
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( strPos - 1
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, str
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, absIdx - 1
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, lineColumn - 1
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, preferredColumn
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, hasPassedLine
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, strTl
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, lineHd
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, lineTl
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)
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structure ViK =
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MakeIfCharFolderPrev
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(struct
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fun helpViK
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( strPos
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, str
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, absIdx
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, lineColumn
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, preferredColumn
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, hasPassedLine
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, strTl
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, lineHd
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, lineTl
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) =
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if strPos < 0 then
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case (strTl, lineTl) of
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(shd :: stl, lhd :: ltl) =>
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helpViK
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( String.size shd - 1
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, shd
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, absIdx
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, lineColumn
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, preferredColumn
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, hasPassedLine
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, stl
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, lhd
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, ltl
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)
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| (_, _) => (* empty, so return start of previous string *)
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absIdx + 1
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else
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case String.sub (str, strPos) of
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#"\n" =>
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if hasPassedLine then
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(* reached line break twice,
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* but line has fewer chars than preferredColumn
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* so go back to chr immediately after this second line break *)
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absIdx + 1
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else
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(* reached start of line once;
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* have to check if this is a double linebreak,
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* and return idx of second linebreak if so *)
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let
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(* have to calculate column of current line
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* so we know which line to stop searching at *)
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val lineColumn = getCursorColumn
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(strPos - 1, str, lineHd, strTl, lineTl, absIdx - 1)
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in
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helpViK
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( strPos - 1
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, str
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, absIdx - 1
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, lineColumn
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, preferredColumn
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, true
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, strTl
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, lineHd
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, lineTl
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)
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end
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| _ =>
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if lineColumn <= preferredColumn andalso hasPassedLine then
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(* We're at or before the preferredColumn so return absIdx
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* context: current line may have fewer columns
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* than our preferred column value.
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* If this is the case, we want to check
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* "is lineColumn equal to or before preferredColumn?". *)
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absIdx
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else
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(* we're not in the preferred column, so keep iterating *)
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helpViK
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( strPos - 1
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, str
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, absIdx - 1
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, lineColumn - 1
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, preferredColumn
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, hasPassedLine
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, strTl
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, lineHd
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, lineTl
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)
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fun startViK (strIdx, shd, cursorIdx, leftStrings, lhd, leftLines) =
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if String.sub (shd, strIdx) = #"\n" then
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(* ? -> ? -> \n *)
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if strIdx > 0 then
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(* strIdx - 1 is in shd *)
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if String.sub (shd, strIdx - 1) = #"\n" then
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(* ? -> \n -> \n *)
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if strIdx > 1 then
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(* strIdx - 2 is in shd *)
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if String.sub (shd, strIdx - 2) = #"\n" then
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(* \n -> \n -> \n
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* so it is safe to decrement cursorIdx by 1 *)
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cursorIdx - 1
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else
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(* graphical-chr -> \n -> \n
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* so go to beginning of line,
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* starting from graphical-chr *)
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startVi0
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(strIdx - 2, shd, lhd, cursorIdx - 2, leftStrings, leftLines)
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else
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(* strIdx - 2 is in leftStrings *)
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case (leftStrings, leftLines) of
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(lshd :: lstl, llhd :: lltl) =>
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if String.sub (lshd, String.size lshd - 1) = #"\n" then
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(* \n -> \n -> \n
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* so it is safe to decrement cursorIdx by 1 *)
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cursorIdx - 1
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else
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(* graphical-chr -> \n -> \n
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* so go to beginning of line,
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* starting from graphical-chr *)
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startVi0
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( String.size lshd - 1
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, lshd
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, llhd
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, cursorIdx - 2
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, lstl
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, lltl
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)
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| (_, _) =>
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(* nothing to the left, so we are at start of buffer *)
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0
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else
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(* ? -> graphical-chr -> \n
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* Don't expect this case to happen
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* but if it does, go to start of line. *)
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startVi0 (strIdx - 1, shd, lhd, cursorIdx - 1, leftStrings, leftLines)
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else
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(* strIdx - 1 is in leftStrings *)
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case (leftStrings, leftLines) of
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(lshd :: lstl, llhd :: lltl) =>
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if String.sub (lshd, String.size lshd - 1) = #"\n" then
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(* ? -> \n -> \n *)
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if String.size lshd > 1 then
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(* cursorIdx - 2 is in this string *)
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if String.sub (lshd, String.size lshd - 2) = #"\n" then
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(* \n -> \n -> \n *)
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cursorIdx - 1
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else
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(* graphical-chr -> \n -> \n *)
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startVi0
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( String.size lshd - 2
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, lshd
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, llhd
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, cursorIdx - 2
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, lstl
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, lltl
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)
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else
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(* cursorIdx - 2 is in lstl *)
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(case (lstl, lltl) of
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(stlhd :: stltl, ltlhd :: lltl) =>
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if String.sub (stlhd, String.size stlhd - 1) = #"\n" then
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(* \n -> \n -> \n *)
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cursorIdx - 1
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fun fStart (strIdx, shd, lhd, cursorIdx, leftStrings, leftLines) =
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if String.sub (shd, strIdx) = #"\n" then
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(* ? -> ? -> \n *)
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if strIdx > 0 then
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(* strIdx - 1 is in shd *)
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if String.sub (shd, strIdx - 1) = #"\n" then
|
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(* ? -> \n -> \n *)
|
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if strIdx > 1 then
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(* strIdx - 2 is in shd *)
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if String.sub (shd, strIdx - 2) = #"\n" then
|
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(* \n -> \n -> \n
|
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* so it is safe to decrement cursorIdx by 1 *)
|
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cursorIdx - 1
|
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else
|
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(* graphical-chr -> \n -> \n
|
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* so go to beginning of line,
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* starting from graphical-chr *)
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startVi0
|
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( strIdx - 2
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, shd
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, lhd
|
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, cursorIdx - 2
|
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, leftStrings
|
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, leftLines
|
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)
|
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else
|
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(* strIdx - 2 is in leftStrings *)
|
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case (leftStrings, leftLines) of
|
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(lshd :: lstl, llhd :: lltl) =>
|
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if String.sub (lshd, String.size lshd - 1) = #"\n" then
|
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(* \n -> \n -> \n
|
||||
* so it is safe to decrement cursorIdx by 1 *)
|
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cursorIdx - 1
|
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else
|
||||
(* graphical-chr -> \n -> \n
|
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* so go to beginning of line,
|
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* starting from graphical-chr *)
|
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startVi0
|
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( String.size lshd - 1
|
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, lshd
|
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, llhd
|
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, cursorIdx - 2
|
||||
, lstl
|
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, lltl
|
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)
|
||||
| (_, _) =>
|
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(* nothing to the left, so we are at start of buffer *)
|
||||
0
|
||||
else
|
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(* ? -> graphical-chr -> \n
|
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* Don't expect this case to happen
|
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* but if it does, go to start of line. *)
|
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startVi0
|
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(strIdx - 1, shd, lhd, cursorIdx - 1, leftStrings, leftLines)
|
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else
|
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(* strIdx - 1 is in leftStrings *)
|
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case (leftStrings, leftLines) of
|
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(lshd :: lstl, llhd :: lltl) =>
|
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if String.sub (lshd, String.size lshd - 1) = #"\n" then
|
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(* ? -> \n -> \n *)
|
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if String.size lshd > 1 then
|
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(* cursorIdx - 2 is in this string *)
|
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if String.sub (lshd, String.size lshd - 2) = #"\n" then
|
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(* \n -> \n -> \n *)
|
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cursorIdx - 1
|
||||
else
|
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(* graphical-chr -> \n -> \n *)
|
||||
startVi0
|
||||
( String.size lshd - 2
|
||||
, lshd
|
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, llhd
|
||||
, cursorIdx - 2
|
||||
, lstl
|
||||
, lltl
|
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)
|
||||
else
|
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(* graphical-chr -> \n -> \n *)
|
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startVi0
|
||||
( String.size stlhd - 1
|
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, stlhd
|
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, ltlhd
|
||||
, cursorIdx - 2
|
||||
, lstl
|
||||
, lltl
|
||||
)
|
||||
| (_, _) => 0)
|
||||
else
|
||||
(* ? -> graphical-chr -> \n *)
|
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startVi0
|
||||
( String.size lshd - 1
|
||||
, lshd
|
||||
, llhd
|
||||
, cursorIdx - 1
|
||||
, leftStrings
|
||||
, leftLines
|
||||
)
|
||||
| (_, _) => (* leftStrings is empty so go to start of buffer *) 0
|
||||
else
|
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(* ? -> ? -> graphical-chr
|
||||
* Normal case where we call startViK. *)
|
||||
let
|
||||
val lineColumn = getCursorColumn
|
||||
(strIdx, shd, lhd, leftStrings, leftLines, cursorIdx)
|
||||
in
|
||||
helpViK
|
||||
( strIdx
|
||||
, shd
|
||||
, cursorIdx
|
||||
, lineColumn
|
||||
, lineColumn
|
||||
, false
|
||||
, leftStrings
|
||||
, lhd
|
||||
, leftLines
|
||||
)
|
||||
end
|
||||
(* cursorIdx - 2 is in lstl *)
|
||||
(case (lstl, lltl) of
|
||||
(stlhd :: stltl, ltlhd :: lltl) =>
|
||||
if String.sub (stlhd, String.size stlhd - 1) = #"\n" then
|
||||
(* \n -> \n -> \n *)
|
||||
cursorIdx - 1
|
||||
else
|
||||
(* graphical-chr -> \n -> \n *)
|
||||
startVi0
|
||||
( String.size stlhd - 1
|
||||
, stlhd
|
||||
, ltlhd
|
||||
, cursorIdx - 2
|
||||
, lstl
|
||||
, lltl
|
||||
)
|
||||
| (_, _) => 0)
|
||||
else
|
||||
(* ? -> graphical-chr -> \n *)
|
||||
startVi0
|
||||
( String.size lshd - 1
|
||||
, lshd
|
||||
, llhd
|
||||
, cursorIdx - 1
|
||||
, leftStrings
|
||||
, leftLines
|
||||
)
|
||||
| (_, _) => (* leftStrings is empty so go to start of buffer *) 0
|
||||
else
|
||||
(* ? -> ? -> graphical-chr
|
||||
* Normal case where we call startViK. *)
|
||||
let
|
||||
val lineColumn = getCursorColumn
|
||||
(strIdx, shd, lhd, leftStrings, leftLines, cursorIdx)
|
||||
in
|
||||
helpViK
|
||||
( strIdx
|
||||
, shd
|
||||
, cursorIdx
|
||||
, lineColumn
|
||||
, lineColumn
|
||||
, false
|
||||
, leftStrings
|
||||
, lhd
|
||||
, leftLines
|
||||
)
|
||||
end
|
||||
|
||||
fun viK (lineGap: LineGap.t, cursorIdx) =
|
||||
let
|
||||
val
|
||||
{rightStrings, idx = bufferIdx, rightLines, leftStrings, leftLines, ...} =
|
||||
lineGap
|
||||
in
|
||||
case (rightStrings, rightLines) of
|
||||
(shd :: stl, lhd :: ltl) =>
|
||||
let
|
||||
(* convert absolute cursorIdx to idx relative to hd string *)
|
||||
val strIdx = cursorIdx - bufferIdx
|
||||
in
|
||||
if strIdx < String.size shd then
|
||||
startViK (strIdx, shd, cursorIdx, leftStrings, lhd, leftLines)
|
||||
else
|
||||
case (stl, ltl) of
|
||||
(stlhd :: stltl, ltlhd :: ltltl) =>
|
||||
let
|
||||
val strIdx = strIdx - String.size shd
|
||||
val leftStrings = shd :: leftStrings
|
||||
val leftLines = lhd :: leftLines
|
||||
in
|
||||
startViK
|
||||
(strIdx, stlhd, cursorIdx, leftStrings, ltlhd, leftLines)
|
||||
end
|
||||
| (_, _) => cursorIdx
|
||||
end
|
||||
| (_, _) => (* nowhere to go rightward, so return cursorIdx *) cursorIdx
|
||||
end
|
||||
end)
|
||||
|
||||
val viK = ViK.foldPrev
|
||||
|
||||
(* equivalent of vi's 'w' command *)
|
||||
val nextWord = ViWordDfa.startOfNextWord
|
||||
@@ -703,60 +671,36 @@ struct
|
||||
val endOfWORD = ViWORDDfa.endOfCurrentWORD
|
||||
val endOfWORDForDelete = ViWORDDfa.endOfCurrentWORDForDelete
|
||||
|
||||
fun helpFirstNonSpaceChr (strPos, str, absIdx, stl, ltl) =
|
||||
if strPos = String.size str then
|
||||
case (stl, ltl) of
|
||||
(shd :: stl, lhd :: ltl) =>
|
||||
helpFirstNonSpaceChr (0, shd, absIdx, stl, ltl)
|
||||
| (_, _) => absIdx - 1
|
||||
else
|
||||
let
|
||||
val chr = String.sub (str, strPos)
|
||||
in
|
||||
if chr = #" " then
|
||||
helpFirstNonSpaceChr (strPos + 1, str, absIdx + 1, stl, ltl)
|
||||
else
|
||||
absIdx
|
||||
end
|
||||
|
||||
fun startFirstNonSpaceChr (shd, strIdx, absIdx, stl, ltl) =
|
||||
if strIdx < String.size shd then
|
||||
helpFirstNonSpaceChr (strIdx, shd, absIdx, stl, ltl)
|
||||
else
|
||||
case (stl, ltl) of
|
||||
(stlhd :: stltl, ltlhd :: ltltl) =>
|
||||
helpFirstNonSpaceChr (0, stlhd, absIdx, stltl, ltltl)
|
||||
| (_, _) => (* tl is empty; just return absIdx *) absIdx
|
||||
|
||||
(* Prerequisite:
|
||||
* LineGap has been moved to start of line (provided with vi0). *)
|
||||
fun firstNonSpaceChr (lineGap: LineGap.t, cursorIdx) =
|
||||
let
|
||||
val {rightStrings, rightLines, idx = bufferIdx, ...} = lineGap
|
||||
in
|
||||
case (rightStrings, rightLines) of
|
||||
(shd :: stl, lhd :: ltl) =>
|
||||
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 *)
|
||||
startFirstNonSpaceChr (shd, strIdx, cursorIdx, stl, ltl)
|
||||
else
|
||||
(* strIdx is in tl *)
|
||||
(case (stl, ltl) of
|
||||
(stlhd :: stltl, ltlhd :: ltltl) =>
|
||||
let
|
||||
val strIdx = strIdx - String.size shd
|
||||
in
|
||||
startFirstNonSpaceChr
|
||||
(stlhd, strIdx, cursorIdx, stltl, ltltl)
|
||||
end
|
||||
| (_, _) => cursorIdx)
|
||||
end
|
||||
| (_, _) => cursorIdx
|
||||
end
|
||||
structure FirstNonSpaceChr =
|
||||
MakeIfCharFolderPrev
|
||||
(struct
|
||||
fun helpFirstNonSpaceChr (strPos, str, absIdx, stl) =
|
||||
if strPos = String.size str then
|
||||
case stl of
|
||||
shd :: stl => helpFirstNonSpaceChr (0, shd, absIdx, stl)
|
||||
| [] => absIdx - 1
|
||||
else
|
||||
let
|
||||
val chr = String.sub (str, strPos)
|
||||
in
|
||||
if chr = #" " then
|
||||
helpFirstNonSpaceChr (strPos + 1, str, absIdx + 1, stl)
|
||||
else
|
||||
absIdx
|
||||
end
|
||||
|
||||
fun fStart (strIdx, shd, _, absIdx, stl, _) =
|
||||
if strIdx < String.size shd then
|
||||
helpFirstNonSpaceChr (strIdx, shd, absIdx, stl)
|
||||
else
|
||||
case stl of
|
||||
stlhd :: stltl => helpFirstNonSpaceChr (0, stlhd, absIdx, stltl)
|
||||
| [] => (* tl is empty; just return absIdx *) absIdx
|
||||
end)
|
||||
|
||||
val firstNonSpaceChr = FirstNonSpaceChr.foldPrev
|
||||
|
||||
fun helpToNextChr (strPos, str, absIdx, stl, ltl, origIdx, findChr) =
|
||||
if strPos = String.size str then
|
||||
|
||||
Reference in New Issue
Block a user