KeyHandler // Reducing the usage of "as!", etc.

Source/Modules/ControllerModules/KeyHandler_HandleCandidate.swift

@@ -37,8 +37,7 @@ import Cocoa
 	) -> Bool {
 		let inputText = input.inputText
 		let charCode: UniChar = input.charCode
-		let ctlCandidateCurrent = delegate!.ctlCandidate(for: self) as! ctlCandidate
+		if let ctlCandidateCurrent = delegate!.ctlCandidate(for: self) as? ctlCandidate {
-
 			// MARK: Cancel Candidate
 
 			let cancelCandidateKey =
@@ -247,16 +246,16 @@ import Cocoa
 				return true
 			}
 
+			// MARK: End Key
+
 			var candidates: [String]!
 
-		if state is InputState.ChoosingCandidate {
+			if let state = state as? InputState.ChoosingCandidate {
-			candidates = (state as! InputState.ChoosingCandidate).candidates
+				candidates = state.candidates
-		} else if state is InputState.AssociatedPhrases {
+			} else if let state = state as? InputState.AssociatedPhrases {
-			candidates = (state as! InputState.AssociatedPhrases).candidates
+				candidates = state.candidates
 			}
 
-		// MARK: End Key
-
 			if candidates.isEmpty {
 				return false
 			} else {  // 這裡不用「count > 0」，因為該整數變數只要「!isEmpty」那就必定滿足這個條件。
@@ -267,7 +266,6 @@ import Cocoa
 					} else {
 						ctlCandidateCurrent.selectedCandidateIndex = UInt(candidates.count - 1)
 					}
-				return true
 				}
 			}
 
@@ -279,7 +277,11 @@ import Cocoa
 
 			var index: Int = NSNotFound
 			var match: String!
-		if state is InputState.AssociatedPhrases { match = input.inputTextIgnoringModifiers } else { match = inputText }
+			if state is InputState.AssociatedPhrases {
+				match = input.inputTextIgnoringModifiers
+			} else {
+				match = inputText
+			}
 
 			var j = 0
 			while j < ctlCandidateCurrent.keyLabels.count {
@@ -294,7 +296,9 @@ import Cocoa
 			if index != NSNotFound {
 				let candidateIndex: UInt = ctlCandidateCurrent.candidateIndexAtKeyLabelIndex(UInt(index))
 				if candidateIndex != UInt.max {
-				delegate!.keyHandler(self, didSelectCandidateAt: Int(candidateIndex), ctlCandidate: ctlCandidateCurrent)
+					delegate!.keyHandler(
+						self, didSelectCandidateAt: Int(candidateIndex), ctlCandidate: ctlCandidateCurrent
+					)
 					return true
 				}
 			}
@@ -353,6 +357,7 @@ import Cocoa
 					return true
 				}
 			}
+		}  // END: "if let ctlCandidateCurrent"
 
 		IME.prtDebugIntel("172A0F81")
 		errorCallback()

Source/Modules/ControllerModules/KeyHandler_HandleInput.swift

@@ -125,16 +125,13 @@ import Cocoa
 
 		// MARK: Handle Marking.
 
-		if state is InputState.Marking {
+		if let marking = state as? InputState.Marking {
-			let marking = state as! InputState.Marking
-
 			if _handleMarkingState(
-				state as! InputState.Marking, input: input, stateCallback: stateCallback,
+				marking, input: input, stateCallback: stateCallback,
 				errorCallback: errorCallback
 			) {
 				return true
 			}
-
 			state = marking.convertToInputting()
 			stateCallback(state)
 		}
@@ -224,16 +221,17 @@ import Cocoa
 
 		// MARK: Calling candidate window using Space or Down or PageUp / PageDn.
 
-		if isPhoneticReadingBufferEmpty() && (state is InputState.NotEmpty)
+		if let currentState = state as? InputState.NotEmpty {
-			&& (input.isExtraChooseCandidateKey || input.isExtraChooseCandidateKeyReverse || input.isSpace
+			if isPhoneticReadingBufferEmpty(),
+				input.isExtraChooseCandidateKey || input.isExtraChooseCandidateKeyReverse || input.isSpace
 					|| input.isPageDown || input.isPageUp || input.isTab
-				|| (input.useVerticalMode && (input.isVerticalModeOnlyChooseCandidateKey)))
+					|| (input.useVerticalMode && (input.isVerticalModeOnlyChooseCandidateKey))
 			{
 				if input.isSpace {
 					// If the Space key is NOT set to be a selection key
 					if input.isShiftHold || !mgrPrefs.chooseCandidateUsingSpace {
 						if getBuilderCursorIndex() >= getBuilderLength() {
-						let composingBuffer = (state as! InputState.NotEmpty).composingBuffer
+							let composingBuffer = currentState.composingBuffer
 							if (composingBuffer.count) != 0 {
 								let committing = InputState.Committing(poppedText: composingBuffer)
 								stateCallback(committing)
@@ -254,12 +252,13 @@ import Cocoa
 					}
 				}
 				let choosingCandidates = _buildCandidateState(
-				state as! InputState.NotEmpty,
+					currentState,
 					useVerticalMode: input.useVerticalMode
 				)
 				stateCallback(choosingCandidates)
 				return true
 			}
+		}
 
 		// MARK: -
 

Source/Modules/ControllerModules/KeyHandler_States.swift

@@ -228,11 +228,13 @@ import Cocoa
 
 		clear()
 
-		let current = state as! InputState.Inputting
+		if let current = state as? InputState.Inputting {
 			let composingBuffer = current.composingBuffer
 
 			let committing = InputState.Committing(poppedText: composingBuffer)
 			stateCallback(committing)
+		}
+
 		let empty = InputState.Empty()
 		stateCallback(empty)
 		return true
@@ -468,8 +470,7 @@ import Cocoa
 			return true
 		}
 
-		let currentState = state as! InputState.Inputting
+		if let currentState = state as? InputState.Inputting {
-
 			if input.isShiftHold {
 				// Shift + Right
 				if currentState.cursorIndex < (currentState.composingBuffer as NSString).length {
@@ -499,6 +500,8 @@ import Cocoa
 					stateCallback(state)
 				}
 			}
+		}
+
 		return true
 	}
 
@@ -519,8 +522,7 @@ import Cocoa
 			return true
 		}
 
-		let currentState = state as! InputState.Inputting
+		if let currentState = state as? InputState.Inputting {
-
 			if input.isShiftHold {
 				// Shift + left
 				if currentState.cursorIndex > 0 {
@@ -550,6 +552,8 @@ import Cocoa
 					stateCallback(state)
 				}
 			}
+		}
+
 		return true
 	}
 }