reimplement vi's 'w' command to use ViWordDfa

fcore/cursor-dfa/vi-word-dfa.sml

@@ -0,0 +1,113 @@
+structure ViWordDfa =
+struct
+  val startState: Word8.word = 0w0
+
+  val startAlpha: Word8.word = 0w1
+  val startSpace: Word8.word = 0w2
+  val startPunct: Word8.word = 0w3
+
+  val alphaToSpace: Word8.word = 0w4
+  val punctToSpace: Word8.word = 0w5
+
+  val alphaToPunct: Word8.word = 0w6
+  val punctToAlpha: Word8.word = 0w7
+
+  val spaceToAlpha: Word8.word = 0w8
+  val spaceToPunct: Word8.word = 0w9
+
+  fun makeStart i =
+    let
+      val chr = Char.chr i
+    in
+      if Char.isAlphaNum chr orelse chr = #"_" then startAlpha
+      else if Char.isSpace chr then startSpace
+      else startPunct
+    end
+
+  fun makeStartAlpha i =
+    let
+      val chr = Char.chr i
+    in
+      if Char.isAlphaNum chr orelse chr = #"_" then startAlpha
+      else if Char.isSpace chr then alphaToSpace
+      else alphaToPunct
+    end
+
+  fun makeStartSpace i =
+    let
+      val chr = Char.chr i
+    in
+      if Char.isAlphaNum chr orelse chr = #"_" then spaceToAlpha
+      else if Char.isSpace chr then startSpace
+      else spaceToPunct
+    end
+
+  fun makeStartPunct i =
+    let
+      val chr = Char.chr i
+    in
+      if Char.isAlphaNum chr orelse chr = #"_" then punctToAlpha
+      else if Char.isSpace chr then punctToSpace
+      else startPunct
+    end
+
+  val startTable = Vector.tabulate (255, makeStart)
+
+  val startAlphaTable = Vector.tabulate (255, makeStartAlpha)
+  val startSpaceTable = Vector.tabulate (255, makeStartSpace)
+  val startPunctTable = Vector.tabulate (255, makeStartPunct)
+
+  val alphaToSpaceTable = startSpaceTable
+  val punctToSpaceTable = startSpaceTable
+
+  val tables =
+   #[ startTable
+    , startAlphaTable
+    , startSpaceTable
+    , startPunctTable
+    , alphaToSpaceTable
+    , punctToSpaceTable
+    ]
+
+  fun next (currentState, chr) =
+    let
+      val currentState = Word8.toInt currentState
+      val currentTable = Vector.sub (tables, currentState)
+      val charIdx = Char.ord chr
+    in
+      Vector.sub (currentTable, charIdx)
+    end
+
+  structure StartOfNextWord =
+    MakeNextDfaLoop
+      (struct
+         val startState = startState
+
+         fun fStart (idx, absIdx, str, tl, currentState, counter) =
+           if idx = String.size str then
+             case tl of
+               str :: tl => fStart (0, absIdx, str, tl, currentState, counter)
+             | [] => Int.max (0, absIdx - 2)
+           else
+             let
+               val chr = String.sub (str, idx)
+               val newState = next (currentState, chr)
+             in
+               if
+                 newState = alphaToPunct orelse newState = punctToAlpha
+                 orelse newState = spaceToAlpha orelse newState = spaceToPunct
+               then
+                 if counter - 1 = 0 then
+                   absIdx
+                 else
+                   (* reset state *)
+                   fStart
+                     (idx + 1, absIdx + 1, str, tl, startState, counter - 1)
+               else
+                 fStart (idx + 1, absIdx + 1, str, tl, newState, counter)
+             end
+       end)
+
+  (* w *)
+  val startOfNextWord = StartOfNextWord.next
+end

fcore/cursor.sml

@@ -863,8 +863,7 @@ struct
     end
 
   (* equivalent of vi's 'w' command *)
-  fun nextWord (lineGap, cursorIdx) =
-    toNextWord (lineGap, cursorIdx, helpNextWord)
+  val nextWord = ViWordDfa.startOfNextWord
 
   (* equivalent of vi's 'W' command *)
   val nextWORD = ViWORDDfa.startOfNextWORD

shf-tests.mlb

@@ -24,6 +24,7 @@ in
   fcore/text-builder.sml
   fcore/cursor-dfa/make-dfa-loop.sml
   fcore/cursor-dfa/vi-WORD-dfa.sml
+  fcore/cursor-dfa/vi-word-dfa.sml
 end
 fcore/cursor.sml
 fcore/text-window.sml

shf.mlb

@@ -24,6 +24,7 @@ in
   fcore/text-builder.sml
   fcore/cursor-dfa/make-dfa-loop.sml
   fcore/cursor-dfa/vi-WORD-dfa.sml
+  fcore/cursor-dfa/vi-word-dfa.sml
 end
 fcore/cursor.sml
 fcore/text-window.sml