in start of cursor.sml's viK function, use vi0 function if cursor is at newline, so there's no need to worry about or track column

This commit is contained in:
2024-10-22 07:06:16 +01:00
parent b22222cf5d
commit dd71dda9f2
2 changed files with 171 additions and 156 deletions

View File

@@ -1,5 +1,151 @@
structure Cursor =
struct
fun helpVi0String (strPos, str, absIdx, strTl, lineTl) =
if strPos < 0 then
helpVi0List (strTl, lineTl, absIdx)
else
case String.sub (str, strPos) of
#"\n" =>
absIdx + 1
| _ =>
helpVi0String (strPos - 1, str, absIdx - 1, strTl, lineTl)
and helpVi0List (strings, lines, absIdx) =
case (strings, lines) of
(strHd::strTl, lineHd::lineTl) =>
helpVi0String
( String.size strHd - 1, strHd, absIdx
, strTl, lineTl
)
| (_, _) =>
(* this case means strings and lines are empty
* and empty means we are at first line
* so we can return 0 *)
0
fun vi0 (lineGap: LineGap.t, cursorIdx) =
let
val
{rightStrings, idx = bufferIdx, rightLines, leftStrings, leftLines, ...} =
lineGap
in
case (rightStrings, rightLines) of
(strHd :: strTl, lnHd :: lnTl) =>
let
(* convert absolute cursorIdx to idx relative to hd string *)
val strIdx = cursorIdx - bufferIdx
in
if strIdx < String.size strHd then
(* strIdx is in this string *)
if String.sub (strHd, strIdx) = #"\n" then
(* don't need to do anything if we are already at newline;
* just return current cursorIdx *)
cursorIdx
else
(* not at newline so start iterating *)
helpVi0String
( strIdx - 1, strHd, cursorIdx - 1
, strTl, lnTl
)
else
(* strIdx must be in the strTl *)
(case (strTl, lnTl) of
(nestStrHd :: _, nestLnHd :: _) =>
let
val strIdx = strIdx - String.size strHd
in
if String.sub (nestStrHd, strIdx) = #"\n" then
(* already at linebreak so return same cursorIdx *)
cursorIdx
else
(* not in linebreak *)
helpVi0String
( strIdx - 1, nestStrHd, cursorIdx - 1
, strHd :: leftStrings, lnHd :: leftLines
)
end
| (_, _) => cursorIdx)
end
| (_, _) =>
(* nowhere to go, so return cursorIdx *)
cursorIdx
end
fun helpViDlrString (strPos, str, absIdx, strTl, lineTl) =
if strPos = String.size str then
helpViDlrList (strTl, lineTl, absIdx)
else
case String.sub (str, strPos) of
#"\n" =>
absIdx - 1
| _ =>
helpViDlrString (strPos + 1, str, absIdx + 1, strTl, lineTl)
and helpViDlrList (strings, lines, absIdx) =
case (strings, lines) of
(strHd::strTl, lineHd::lineTl) =>
helpViDlrString
(0, strHd, absIdx , strTl, lineTl)
| (_, _) =>
(* this case means strings and lines are empty
* and empty means we have reached end of lineGap
* so we can return last chr *)
absIdx - 1
fun viDlr(lineGap: LineGap.t, cursorIdx) =
let
val
{rightStrings, idx = bufferIdx, rightLines, leftStrings, leftLines, ...} =
lineGap
in
case (rightStrings, rightLines) of
(strHd :: strTl, lnHd :: lnTl) =>
let
(* convert absolute cursorIdx to idx relative to hd string *)
val strIdx = cursorIdx - bufferIdx
in
if strIdx < String.size strHd then
if String.sub (strHd, strIdx) <> #"\n" then
(* not in double linebreak *)
helpViDlrString
(strIdx + 1, strHd, cursorIdx + 1, strTl, lnTl)
else
(* check if we are in double linebreak *)
if strIdx - 1 >= 0 then
if String.sub (strHd, strIdx - 1) = #"\n" then
(* we are in double linebreak, so do nothing *)
cursorIdx
else
(* not in double linebreak, so iterate *)
helpViDlrString
(strIdx + 1, strHd, cursorIdx + 1 , strTl, lnTl)
else
(* check if double linebreak in strTl *)
(case strTl of
nestStrHd :: _ =>
if String.sub (nestStrHd, 0) = #"\n" then
cursorIdx
else
helpViDlrString
(strIdx + 1, strHd, cursorIdx + 1, strTl, lnTl)
| [] => cursorIdx)
else
(* strIdx must be in the strTl *)
(case (strTl, lnTl) of
(nestStrHd :: nestStrTl, nestLnHd :: nestLnTl) =>
let
val strIdx = strIdx - String.size strHd
in
helpViDlrString
(strIdx + 1, nestStrHd, cursorIdx + 1, nestStrTl, nestLnTl)
end
| (_, _) => cursorIdx)
end
| (_, _) =>
(* nowhere to go, so return cursorIdx *)
cursorIdx
end
(* Prerequisite: lineGap is moved to requested idx first
* todo: check if we are in a \r\n pair, but this is not a priority *)
fun viL (lineGap: LineGap.t, cursorIdx) =
@@ -484,7 +630,7 @@ struct
absIdx
else
(* not in double linebreak *)
absIdx - 1
absIdx - 1
else
(* check for double linebreak in tl *)
(case strTl of
@@ -592,15 +738,30 @@ struct
if strIdx < String.size strHd then
(* strIdx is in this string *)
if String.sub (strHd, strIdx) = #"\n" then
(* if we are at a newline
* note:
* don't need to check if we are a double linebreak,
* because cursor navigation functions already check
* for that condition at the end.
* So there is no way at the start of a navigation function
* that cursor is in a double linebreak incorrectly. *)
helpViKString
(strIdx - 1, strHd, cursorIdx - 1, 0, 0, true, strTl, lnHd, lnTl)
(* if we are at a newline *)
if strIdx > 0 then
if String.sub (strHd, strIdx - 1) = #"\n" then
(* if in double linebreak *)
helpVi0String
(strIdx - 2, strHd, cursorIdx - 2, strTl, lnTl)
else
(* not in double linebreak *)
helpVi0String
(strIdx - 1, strHd, cursorIdx - 1, strTl, lnTl)
else
(* check leftStrings to see if we are in a double linebreak *)
(case (leftStrings, leftLines) of
(lStrHd :: lStrTl, lLnHd :: lLnTl) =>
if String.sub (lStrHd, String.size lStrHd - 1) = #"\n" then
(* in double linebreak *)
helpVi0String
(String.size lStrHd - 2, lStrHd, cursorIdx - 2, lStrTl, lLnTl)
else
helpVi0String
(strIdx - 1, strHd, cursorIdx - 1, strTl, lnTl)
| (_, _) =>
helpViKString
(strIdx - 1, strHd, cursorIdx - 1, 0, 0, true, strTl, lnHd, lnTl))
else
(* not at newline
* so get column number and start iterating *)
@@ -646,150 +807,4 @@ struct
(* nowhere to go rightward, so return cursorIdx *)
cursorIdx
end
fun helpVi0String (strPos, str, absIdx, strTl, lineTl) =
if strPos < 0 then
helpVi0List (strTl, lineTl, absIdx)
else
case String.sub (str, strPos) of
#"\n" =>
absIdx + 1
| _ =>
helpVi0String (strPos - 1, str, absIdx - 1, strTl, lineTl)
and helpVi0List (strings, lines, absIdx) =
case (strings, lines) of
(strHd::strTl, lineHd::lineTl) =>
helpVi0String
( String.size strHd - 1, strHd, absIdx
, strTl, lineTl
)
| (_, _) =>
(* this case means strings and lines are empty
* and empty means we are at first line
* so we can return 0 *)
0
fun vi0 (lineGap: LineGap.t, cursorIdx) =
let
val
{rightStrings, idx = bufferIdx, rightLines, leftStrings, leftLines, ...} =
lineGap
in
case (rightStrings, rightLines) of
(strHd :: strTl, lnHd :: lnTl) =>
let
(* convert absolute cursorIdx to idx relative to hd string *)
val strIdx = cursorIdx - bufferIdx
in
if strIdx < String.size strHd then
(* strIdx is in this string *)
if String.sub (strHd, strIdx) = #"\n" then
(* don't need to do anything if we are already at newline;
* just return current cursorIdx *)
cursorIdx
else
(* not at newline so start iterating *)
helpVi0String
( strIdx - 1, strHd, cursorIdx - 1
, strTl, lnTl
)
else
(* strIdx must be in the strTl *)
(case (strTl, lnTl) of
(nestStrHd :: _, nestLnHd :: _) =>
let
val strIdx = strIdx - String.size strHd
in
if String.sub (nestStrHd, strIdx) = #"\n" then
(* already at linebreak so return same cursorIdx *)
cursorIdx
else
(* not in linebreak *)
helpVi0String
( strIdx - 1, nestStrHd, cursorIdx - 1
, strHd :: leftStrings, lnHd :: leftLines
)
end
| (_, _) => cursorIdx)
end
| (_, _) =>
(* nowhere to go, so return cursorIdx *)
cursorIdx
end
fun helpViDlrString (strPos, str, absIdx, strTl, lineTl) =
if strPos = String.size str then
helpViDlrList (strTl, lineTl, absIdx)
else
case String.sub (str, strPos) of
#"\n" =>
absIdx - 1
| _ =>
helpViDlrString (strPos + 1, str, absIdx + 1, strTl, lineTl)
and helpViDlrList (strings, lines, absIdx) =
case (strings, lines) of
(strHd::strTl, lineHd::lineTl) =>
helpViDlrString
(0, strHd, absIdx , strTl, lineTl)
| (_, _) =>
(* this case means strings and lines are empty
* and empty means we have reached end of lineGap
* so we can return last chr *)
absIdx - 1
fun viDlr(lineGap: LineGap.t, cursorIdx) =
let
val
{rightStrings, idx = bufferIdx, rightLines, leftStrings, leftLines, ...} =
lineGap
in
case (rightStrings, rightLines) of
(strHd :: strTl, lnHd :: lnTl) =>
let
(* convert absolute cursorIdx to idx relative to hd string *)
val strIdx = cursorIdx - bufferIdx
in
if strIdx < String.size strHd then
if String.sub (strHd, strIdx) <> #"\n" then
(* not in double linebreak *)
helpViDlrString
(strIdx + 1, strHd, cursorIdx + 1, strTl, lnTl)
else
(* check if we are in double linebreak *)
if strIdx - 1 >= 0 then
if String.sub (strHd, strIdx - 1) = #"\n" then
(* we are in double linebreak, so do nothing *)
cursorIdx
else
(* not in double linebreak, so iterate *)
helpViDlrString
(strIdx + 1, strHd, cursorIdx + 1 , strTl, lnTl)
else
(* check if double linebreak in strTl *)
(case strTl of
nestStrHd :: _ =>
if String.sub (nestStrHd, 0) = #"\n" then
cursorIdx
else
helpViDlrString
(strIdx + 1, strHd, cursorIdx + 1, strTl, lnTl)
| [] => cursorIdx)
else
(* strIdx must be in the strTl *)
(case (strTl, lnTl) of
(nestStrHd :: nestStrTl, nestLnHd :: nestLnTl) =>
let
val strIdx = strIdx - String.size strHd
in
helpViDlrString
(strIdx + 1, nestStrHd, cursorIdx + 1, nestStrTl, nestLnTl)
end
| (_, _) => cursorIdx)
end
| (_, _) =>
(* nowhere to go, so return cursorIdx *)
cursorIdx
end
end

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