Add 'shf/' from commit 'b6c5a95b664aeb861d7b33ffc9eefe447ba99dd7'

git-subtree-dir: shf
git-subtree-mainline: 401408448f
git-subtree-split: b6c5a95b66

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

@@ -0,0 +1,285 @@
+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 spaceToAlpha: Word8.word = 0w6
+  val spaceToPunct: Word8.word = 0w7
+
+  val startNewline: Word8.word = 0w8
+  val newlineToNewline: Word8.word = 0w9
+  val chrToNewline: Word8.word = 0w10
+
+  val newlineToAlpha: Word8.word = 0w11
+  val newlineToPunct: Word8.word = 0w12
+
+  val alphaToPunct: Word8.word = 0w13
+  val punctToAlpha: Word8.word = 0w14
+
+  fun makeStart i =
+    let
+      val chr = Char.chr i
+    in
+      if Char.isAlphaNum chr orelse chr = #"_" then startAlpha
+      else if chr = #"\n" then startNewline
+      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 chr = #"\n" then chrToNewline
+      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 chr = #"\n" then chrToNewline
+      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 chr = #"\n" then chrToNewline
+      else if Char.isSpace chr then punctToSpace
+      else startPunct
+    end
+
+  fun makeStartNewline i =
+    let
+      val chr = Char.chr i
+    in
+      if Char.isAlphaNum chr orelse chr = #"_" then newlineToAlpha
+      else if chr = #"\n" then newlineToNewline
+      else if Char.isSpace chr then startSpace
+      else newlineToPunct
+    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 spaceToAlphaTable = startAlphaTable
+  val spaceToPunctTable = startPunctTable
+
+  val newlineTable = Vector.tabulate (255, makeStartNewline)
+
+  val tables =
+   #[ startTable
+
+    , startAlphaTable
+    , startSpaceTable
+    , startPunctTable
+
+    , alphaToSpaceTable
+    , punctToSpaceTable
+
+    , spaceToAlphaTable
+    , spaceToPunctTable
+
+    , newlineTable
+    , newlineTable
+    , newlineTable
+
+    , startAlphaTable
+    , startPunctTable
+    ]
+
+  structure StartOfNextWord =
+    MakeNextDfaLoop
+      (struct
+         val startState = startState
+
+         structure Folder =
+           MakeCharFolderNext
+             (struct
+                val startState = startState
+                val tables = tables
+
+                fun isFinal currentState =
+                  currentState = alphaToPunct orelse currentState = punctToAlpha
+                  orelse currentState = spaceToAlpha
+                  orelse currentState = spaceToPunct
+                  orelse currentState = newlineToNewline
+                  orelse currentState = newlineToAlpha
+                  orelse currentState = newlineToPunct
+
+                fun finish x = x
+              end)
+
+         val fStart = Folder.foldNext
+       end)
+
+  (* This is the same as StartOfNextWord, except for the `isFinal` function.
+   * The difference is that the `isFinal` function here considers
+   * the state where any character goes to a newline,
+   * to be a final state.
+   * This is because, in Vim, the 'w' motion will move past a newline
+   * when that newline is preceded by a non-newline character.
+   * However, the 'dw' motion deletes until that newline 
+   * (not including the newline itself).
+   * It is easier, less fragile, and perhaps clearer,
+   * to implement the difference using a transition table like this
+   * than convoluted if-statements. *)
+  structure StartOfNextWordForDelete =
+    MakeNextDfaLoop
+      (struct
+         val startState = startState
+
+         structure Folder =
+           MakeCharFolderNext
+             (struct
+                val startState = startState
+                val tables = tables
+
+                fun isFinal currentState =
+                  currentState = alphaToPunct orelse currentState = punctToAlpha
+                  orelse currentState = spaceToAlpha
+                  orelse currentState = spaceToPunct
+                  orelse currentState = chrToNewline
+
+                fun finish x = x
+              end)
+
+         val fStart = Folder.foldNext
+       end)
+
+  structure EndOfPrevWord =
+    MakePrevDfaLoop
+      (struct
+         val startState = startState
+
+         structure Folder =
+           MakeCharFolderPrev
+             (struct
+                val startState = startState
+                val tables = tables
+
+                fun isFinal currentState =
+                  currentState = alphaToPunct orelse currentState = punctToAlpha
+                  orelse currentState = spaceToAlpha
+                  orelse currentState = spaceToPunct
+                  orelse currentState = newlineToNewline
+                  orelse currentState = newlineToAlpha
+                  orelse currentState = newlineToPunct
+
+                fun finish x = x
+              end)
+
+         val fStart = Folder.foldPrev
+       end)
+
+  structure StartOfCurrentWordFolder =
+    MakeCharFolderPrev
+      (struct
+         val startState = startState
+         val tables = tables
+
+         fun isFinal currentState =
+           currentState = alphaToSpace orelse currentState = punctToSpace
+           orelse currentState = alphaToPunct orelse currentState = punctToAlpha
+           orelse currentState = chrToNewline
+           orelse currentState = newlineToNewline
+
+         fun finish idx = idx + 1
+       end)
+
+  structure StartOfCurrentWord =
+    MakePrevDfaLoopMinus1
+      (struct
+         val startState = startState
+         val fStart = StartOfCurrentWordFolder.foldPrev
+       end)
+
+  structure StartOfCurrentWordStrict =
+    MakePrevDfaLoop
+      (struct
+         val startState = startState
+         val fStart = StartOfCurrentWordFolder.foldPrev
+       end)
+
+  fun isFinalForEndOfCurrentWord currentState =
+    currentState = alphaToSpace orelse currentState = punctToSpace
+    orelse currentState = alphaToPunct orelse currentState = punctToAlpha
+    orelse currentState = chrToNewline
+
+  structure EndOfCurrentWordFolder =
+    MakeCharFolderNext
+      (struct
+         val startState = startState
+         val tables = tables
+
+         val isFinal = isFinalForEndOfCurrentWord
+         fun finish x = x - 1
+       end)
+
+  structure EndOfCurrentWord =
+    MakeNextDfaLoopPlus1
+      (struct
+         val startState = startState
+         val fStart = EndOfCurrentWordFolder.foldNext
+       end)
+
+  structure EndOfCurrentWordStrict =
+    MakeNextDfaLoop
+      (struct
+         val startState = startState
+         val fStart = EndOfCurrentWordFolder.foldNext
+       end)
+
+  structure EndOfCurrentWordForDelete =
+    MakeNextDfaLoopPlus1
+      (struct
+         val startState = startState
+
+         structure Folder =
+           MakeCharFolderNext
+             (struct
+                val startState = startState
+                val tables = tables
+
+                val isFinal = isFinalForEndOfCurrentWord
+                fun finish x = x
+              end)
+
+         val fStart = Folder.foldNext
+       end)
+
+  (* w *)
+  val startOfNextWord = StartOfNextWord.next
+  val startOfNextWordForDelete = StartOfNextWordForDelete.next
+  (* ge *)
+  val endOfPrevWord = EndOfPrevWord.prev
+  (* b *)
+  val startOfCurrentWord = StartOfCurrentWord.prev
+  (* e *)
+  val endOfCurrentWord = EndOfCurrentWord.next
+  val endOfCurrentWordForDelete = EndOfCurrentWordForDelete.next
+
+  (* the meaning of "Strict" and the utility of these two functions
+   * is described in vi-WORD-dfa.sml *)
+  val startOfCurrentWordStrict = StartOfCurrentWordStrict.prev
+  val endOfCurrentWordStrict = EndOfCurrentWordStrict.next
+end