Use let instead of var when it's possible.

These usage of `var` instead of `let` causes Swift compiler
warnings.

Author: niw

runtime/Swift/Sources/Antlr4/Lexer.swift

@@ -132,7 +132,7 @@ open class Lexer: Recognizer<LexerATNSimulator>, TokenSource {
 
         // Mark start location in char stream so unbuffered streams are
         // guaranteed at least have text of current token
-        var tokenStartMarker = _input.mark()
+        let tokenStartMarker = _input.mark()
         defer {
             // make sure we release marker after match or
             // unbuffered char stream will keep buffering

runtime/Swift/Sources/Antlr4/atn/LexerATNSimulator.swift

@@ -116,7 +116,7 @@ open class LexerATNSimulator: ATNSimulator {
         LexerATNSimulator.match_calls += 1
 
         self.mode = mode
-        var mark = input.mark()
+        let mark = input.mark()
         defer {
             try! input.release(mark)
         }
@@ -609,10 +609,10 @@ open class LexerATNSimulator: ATNSimulator {
             return try recog.sempred(nil, ruleIndex, predIndex)
         }
 
-        var savedCharPositionInLine = charPositionInLine
-        var savedLine = line
-        var index = input.index()
-        var marker = input.mark()
+        let savedCharPositionInLine = charPositionInLine
+        let savedLine = line
+        let index = input.index()
+        let marker = input.mark()
         do {
             try consume(input)
             defer

runtime/Swift/Sources/Antlr4/atn/LexerActionExecutor.swift

@@ -149,7 +149,7 @@ public class LexerActionExecutor: Hashable {
     /// 
     public func execute(_ lexer: Lexer, _ input: CharStream, _ startIndex: Int) throws {
         var requiresSeek: Bool = false
-        var stopIndex: Int = input.index()
+        let stopIndex: Int = input.index()
         defer {
             if requiresSeek {
                 try! input.seek(stopIndex)

runtime/Swift/Sources/Antlr4/atn/ProfilingATNSimulator.swift

@@ -53,17 +53,17 @@ public class ProfilingATNSimulator: ParserATNSimulator {
 
     override
     public func adaptivePredict(_ input: TokenStream, _ decision: Int,_ outerContext: ParserRuleContext?) throws -> Int {
-        var outerContext = outerContext
+        let outerContext = outerContext
         self._sllStopIndex = -1
         self._llStopIndex = -1
         self.currentDecision = decision
-        var start: Int64 = Int64(Date().timeIntervalSince1970) //System.nanoTime(); // expensive but useful info
-        var alt: Int = try  super.adaptivePredict(input, decision, outerContext)
-        var stop: Int64 = Int64(Date().timeIntervalSince1970)  //System.nanoTime();
+        let start: Int64 = Int64(Date().timeIntervalSince1970) //System.nanoTime(); // expensive but useful info
+        let alt: Int = try  super.adaptivePredict(input, decision, outerContext)
+        let stop: Int64 = Int64(Date().timeIntervalSince1970)  //System.nanoTime();
         decisions[decision].timeInPrediction += (stop - start)
         decisions[decision].invocations += 1
 
-        var SLL_k: Int64 = Int64(_sllStopIndex - _startIndex + 1)
+        let SLL_k: Int64 = Int64(_sllStopIndex - _startIndex + 1)
         decisions[decision].SLL_TotalLook += SLL_k
         decisions[decision].SLL_MinLook = decisions[decision].SLL_MinLook == 0 ? SLL_k : min(decisions[decision].SLL_MinLook, SLL_k)
         if SLL_k > decisions[decision].SLL_MaxLook {
@@ -73,7 +73,7 @@ public class ProfilingATNSimulator: ParserATNSimulator {
         }
 
         if _llStopIndex >= 0 {
-            var LL_k: Int64 = Int64(_llStopIndex - _startIndex + 1)
+            let LL_k: Int64 = Int64(_llStopIndex - _startIndex + 1)
             decisions[decision].LL_TotalLook += LL_k
             decisions[decision].LL_MinLook = decisions[decision].LL_MinLook == 0 ? LL_k : min(decisions[decision].LL_MinLook, LL_k)
             if LL_k > decisions[decision].LL_MaxLook {