progress with equivalent of vi's 'x' command

This commit is contained in:
2024-11-05 12:38:01 +00:00
parent a0a8fcc17b
commit 9df6f92a33
3 changed files with 173 additions and 15 deletions

View File

@@ -6,6 +6,14 @@ struct
open DrawMsg
open InputMsg
fun clearMode app =
let
val mode = NORMAL_MODE ""
val newApp = AppWith.mode (app, mode)
in
(newApp, [])
end
fun resizeText (app: app_type, newWidth, newHeight) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
@@ -170,8 +178,6 @@ struct
then
(* if visible, just need to redraw; no need to get line *)
let
val buffer = LineGap.goToLine (startLine, buffer)
val newApp = AppWith.bufferAndCursorIdx
(app, buffer, cursorIdx, NORMAL_MODE "", startLine)
@@ -226,6 +232,72 @@ struct
(newApp, drawMsg)
end
(* equivalent of vi's 'x' command *)
fun deleteChr (app: app_type, count) =
let
val {buffer, cursorIdx, startLine, windowWidth, windowHeight, ...} = app
val buffer = LineGap.goToIdx (cursorIdx, buffer)
(* Explanation of how Vi's 'x' command behaves:
* If the cursor is at the end of the file,
* then it is decremented by 1.
* If the character after the cursor is a line break,
* then it is also decremented by 1.
* If the character before the cursor is a linee break, the cursor stays
* where it is.
* If the chracter AT the cursor is a line break and the characater
* AFTER the cursor is also a line break, then nothing is deleted.
* Otherwise, the same cursor is returned.
* All decrement cases do not decrement when the cursor is 0. *)
val cursorIsStart = Cursor.isCursorAtStartOfLine (buffer, cursorIdx)
val nextIsEnd = Cursor.isNextChrEndOfLine (buffer, cursorIdx)
in
if nextIsEnd andalso cursorIsStart then
(* vi simply doesn't do anything on 'x' command
* when cursor is at start of line, and next chr is line break *)
clearMode app
else if cursorIsStart then
let val _ = print "260\n" in
clearMode app end
else if nextIsEnd then
let
(* delete char at cursor and then decrement cursorIdx by 1
* if cursorIdx is not 0 *)
val newBuffer = LineGap.delete (cursorIdx, 1, buffer)
val cursorIdx =
if Cursor.isPrevChrStartOfLine (newBuffer, cursorIdx)
orelse cursorIdx = 0 then
cursorIdx
else cursorIdx - 1
val newBuffer = LineGap.goToLine (startLine, newBuffer)
val newApp = AppWith.bufferAndCursorIdx
(app, newBuffer, cursorIdx, NORMAL_MODE "", startLine)
val drawMsg =
TextBuilder.build
(startLine, cursorIdx, newBuffer, windowWidth, windowHeight)
in
(newApp, drawMsg)
end
else if Cursor.isPrevChrStartOfLine (buffer, cursorIdx) then
clearMode app
else
let
val newBuffer = LineGap.delete (cursorIdx, 1, buffer)
val newBuffer = LineGap.goToLine (startLine, newBuffer)
val newApp = AppWith.bufferAndCursorIdx
(app, newBuffer, cursorIdx, NORMAL_MODE "", startLine)
val drawMsg =
TextBuilder.build
(startLine, cursorIdx, newBuffer, windowWidth, windowHeight)
in
(newApp, drawMsg)
end
end
(* number of characters which are integers *)
fun getNumLength (pos, str) =
if pos = String.size str then
@@ -295,6 +367,7 @@ struct
else
moveToLine (app, count - 1)
| #"%" => moveToMatchingPair app
| #"x" => deleteChr (app, count)
(* multi-char commands which can be appended *)
| #"t" => appendChr (app, chr, str)
| #"T" => appendChr (app, chr, str)
@@ -355,15 +428,6 @@ struct
in helpMoveToChr (app, buffer, cursorIdx, count, fMove, chr)
end
(* temp placeholder function *)
fun clearMode app =
let
val mode = NORMAL_MODE ""
val newApp = AppWith.mode (app, mode)
in
(newApp, [])
end
fun handleMoveToChr (count, app, fMove, newCmd) =
case newCmd of
CHAR_EVENT chr => moveToChr (app, count, fMove, chr)

View File

@@ -31,7 +31,8 @@ struct
cursorIdx
else
(* not at newline so start iterating *)
helpVi0 (strIdx - 1, strHd, cursorIdx - 1, strTl, lnTl)
helpVi0
(strIdx - 1, strHd, cursorIdx - 1, leftStrings, leftLines)
else
(* strIdx must be in the strTl *)
(case (strTl, lnTl) of
@@ -977,18 +978,18 @@ struct
(case (stl, ltl) of
(stlhd :: stltl, ltlhd :: ltltl) =>
let val strIdx = strIdx - String.size shd
in fNext (strIdx, shd, cursorIdx, stltl, ltltl)
in fNext (strIdx, stlhd, cursorIdx, stltl, ltltl)
end
| (_, _) => cursorIdx)
end
| (_, _) => cursorIdx
end
(* equivalent 'f vi's 'w' command *)
(* equivalent of vi's 'w' command *)
fun nextWord (lineGap, cursorIdx) =
toNextWord (lineGap, cursorIdx, helpNextWord)
(* equivalent 'f vi's 'W' command *)
(* equivalent of vi's 'W' command *)
fun nextWORD (lineGap, cursorIdx) =
toNextWord (lineGap, cursorIdx, helpNextWORD)
@@ -1742,4 +1743,97 @@ struct
| (_, _) => 0)
end
end
(* Prerequisite: lineGap is moved to cursorIdx *)
fun isCursorAtStartOfLine (lineGap: LineGap.t, cursorIdx) =
let
val {rightStrings, idx = bufferIdx, ...} = lineGap
in
case rightStrings of
hd :: tl =>
let
(* convert absolute cursorIdx to idx relative to hd string *)
val strIdx = cursorIdx - bufferIdx
in
if strIdx < String.size hd then
(* chr is in hd *)
String.sub (hd, strIdx) = #"\n"
else
(* chr is in tl *)
(case tl of
tlhd :: _ =>
let
val strIdx = strIdx - String.size hd
in
String.sub (tlhd, strIdx) = #"\n"
end
| [] => true)
end
| [] => true
end
(* Prerequisite: lineGap is moved to cursorIdx *)
fun isPrevChrStartOfLine (lineGap: LineGap.t, cursorIdx) =
let
val {rightStrings, idx = bufferIdx, leftStrings, ...} = lineGap
in
case rightStrings of
hd :: tl =>
let
(* convert absolute cursorIdx to idx relative to hd string *)
val strIdx = cursorIdx - bufferIdx
in
if strIdx > 0 then
(* prev chr is in hd *)
String.sub (hd, strIdx - 1) = #"\n"
else
(* prev chr if in leftStrings *)
(case leftStrings of
lhd :: _ =>
String.sub (lhd, String.size lhd - 1) = #"\n"
| [] =>
(* cursorIdx = 0 which means we are at start of file/line *)
true)
end
| [] =>
true
end
fun helpIsNextChrEndOfLine (strIdx, hd, tl) =
if strIdx + 1 < String.size hd then
(* next chr is in this string *)
String.sub (hd, strIdx + 1) = #"\n"
else
(* next chr, if it exists, is in tl *)
(case tl of
tlhd :: _ =>
String.sub (tlhd, 0) = #"\n"
| [] =>
true)
(* Prerequisite: lineGap is moved to cursorIdx *)
fun isNextChrEndOfLine (lineGap: LineGap.t, cursorIdx) =
let
val {rightStrings, idx = bufferIdx, ...} = lineGap
in
case rightStrings of
hd :: tl =>
let
(* convert absolute cursorIdx to idx relative to hd string *)
val strIdx = cursorIdx - bufferIdx
in
if strIdx < String.size hd then
helpIsNextChrEndOfLine (strIdx, hd, tl)
else
(* strIdx is in tl *)
(case tl of
tlhd :: tltl =>
helpIsNextChrEndOfLine (strIdx, tlhd, tltl)
| [] =>
(* strIdx is at end of lineGap
* which also means at end of line *)
true)
end
| [] => true
end
end

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