[Swift] use stdlib (single pass)

runtime/Swift/Sources/Antlr4/BufferedTokenStream.swift

@@ -171,7 +171,7 @@ public class BufferedTokenStream: TokenStream {
     }
 
     public func get(_ i: Int) throws -> Token {
-        if i < 0 || i >= tokens.count {
+        guard tokens.indices.contains(i) else {
             throw ANTLRError.indexOutOfBounds(msg: "token index \(i) out of range 0 ..< \(tokens.count)")
         }
         return tokens[i]
@@ -284,8 +284,8 @@ public class BufferedTokenStream: TokenStream {
     /// 
     public func getTokens(_ start: Int, _ stop: Int, _ types: Set<Int>?) throws -> [Token]? {
         try lazyInit()
-        if start < 0 || start >= tokens.count ||
-            stop < 0 || stop >= tokens.count {
+        guard tokens.indices.contains(start),
+              tokens.indices.contains(stop) else {
             throw ANTLRError.indexOutOfBounds(msg: "start \(start) or stop \(stop) not in 0 ..< \(tokens.count)")
 
         }
@@ -309,9 +309,7 @@ public class BufferedTokenStream: TokenStream {
     }
 
     public func getTokens(_ start: Int, _ stop: Int, _ ttype: Int) throws -> [Token]? {
-        var s = Set<Int>()
-        s.insert(ttype)
-        return try getTokens(start, stop, s)
+        return try getTokens(start, stop, [ttype])
     }
 
     /// 
@@ -378,7 +376,7 @@ public class BufferedTokenStream: TokenStream {
     /// 
     public func getHiddenTokensToRight(_ tokenIndex: Int, _ channel: Int = -1) throws -> [Token]? {
         try lazyInit()
-        if tokenIndex < 0 || tokenIndex >= tokens.count {
+        guard tokens.indices.contains(tokenIndex) else {
             throw ANTLRError.indexOutOfBounds(msg: "\(tokenIndex) not in 0 ..< \(tokens.count)")
         }
 
@@ -403,7 +401,7 @@ public class BufferedTokenStream: TokenStream {
     /// 
     public func getHiddenTokensToLeft(_ tokenIndex: Int, _ channel: Int = -1) throws -> [Token]? {
         try lazyInit()
-        if tokenIndex < 0 || tokenIndex >= tokens.count {
+        guard tokens.indices.contains(tokenIndex) else {
             throw ANTLRError.indexOutOfBounds(msg: "\(tokenIndex) not in 0 ..< \(tokens.count)")
         }
 

runtime/Swift/Sources/Antlr4/DiagnosticErrorListener.swift

@@ -102,7 +102,7 @@ public class DiagnosticErrorListener: BaseErrorListener {
         let ruleIndex: Int = dfa.atnStartState.ruleIndex!
 
         let ruleNames: [String] = recognizer.getRuleNames()
-        if ruleIndex < 0 || ruleIndex >= ruleNames.count {
+        guard ruleNames.indices.contains(ruleIndex) else {
             return String(decision)
         }
 

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

@@ -139,7 +139,7 @@ public class ATN {
     /// number `stateNumber`
     /// 
     public func getExpectedTokens(_ stateNumber: Int, _ context: RuleContext) throws -> IntervalSet {
-        if stateNumber < 0 || stateNumber >= states.count {
+        guard states.indices.contains(stateNumber) else {
             throw ANTLRError.illegalArgument(msg: "Invalid state number.")
         }
 

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

@@ -252,18 +252,7 @@ public class SemanticContext: Hashable, CustomStringConvertible {
                 return self
             }
 
-            if operands.isEmpty {
-                // all elements were true, so the AND context is true
-                return SemanticContext.NONE
-            }
-
-            var result = operands[0]
-            let length = operands.count
-            for i in 1..<length {
-                result = SemanticContext.and(result, operands[i])
-            }
-
-            return result
+            return operands.reduce(SemanticContext.NONE, SemanticContext.and)
         }
 
         override
@@ -354,18 +343,7 @@ public class SemanticContext: Hashable, CustomStringConvertible {
                 return self
             }
 
-            if operands.isEmpty {
-                // all elements were false, so the OR context is false
-                return nil
-            }
-
-            var result = operands[0]
-            let length = operands.count
-            for i in 1..<length {
-                result = SemanticContext.or(result, operands[i])
-            }
-
-            return result
+            return operands.reduce(nil, SemanticContext.or)
         }
 
         override

runtime/Swift/Sources/Antlr4/misc/BitSet.swift

@@ -633,7 +633,7 @@ public class BitSet: Hashable, CustomStringConvertible {
 
         while true {
             if word != 0 {
-                let bit = (u * BitSet.BITS_PER_WORD) + BitSet.numberOfTrailingZeros(word)
+                let bit = (u * BitSet.BITS_PER_WORD) + word.trailingZeroBitCount
                 return bit
             }
             u += 1
@@ -644,44 +644,6 @@ public class BitSet: Hashable, CustomStringConvertible {
         }
     }
 
-    public static func numberOfTrailingZeros(_ i: Int64) -> Int {
-        // HD, Figure 5-14
-        var x: Int32, y: Int32
-        if i == 0 {
-            return 64
-        }
-        var n: Int32 = 63
-        y = Int32(truncatingIfNeeded: i)
-        if y != 0 {
-            n = n - 32
-            x = y
-        } else {
-            x = Int32(truncatingIfNeeded: i >>> 32)
-        }
-
-        y = x << 16
-        if y != 0 {
-            n = n - 16
-            x = y
-        }
-        y = x << 8
-        if y != 0 {
-            n = n - 8
-            x = y
-        }
-        y = x << 4
-        if y != 0 {
-            n = n - 4
-            x = y
-        }
-        y = x << 2
-        if y != 0 {
-            n = n - 2
-            x = y
-        }
-        return Int(n - ((x << 1) >>> 31))
-    }
-
     /// 
     /// Returns the index of the first bit that is set to `false`
     /// that occurs on or after the specified starting index.
@@ -708,7 +670,7 @@ public class BitSet: Hashable, CustomStringConvertible {
 
         while true {
             if word != 0 {
-                return (u * BitSet.BITS_PER_WORD) + BitSet.numberOfTrailingZeros(word)
+                return (u * BitSet.BITS_PER_WORD) + word.trailingZeroBitCount
             }
             u += 1
             if u == wordsInUse {
@@ -759,7 +721,7 @@ public class BitSet: Hashable, CustomStringConvertible {
         var word: Int64 = words[u] & (BitSet.WORD_MASK >>> Int64(-(fromIndex + 1)))
         while true {
             if word != 0 {
-                return (u + 1) * BitSet.BITS_PER_WORD - 1 - BitSet.numberOfLeadingZeros(word)
+                return (u + 1) * BitSet.BITS_PER_WORD - 1 - word.leadingZeroBitCount
             }
             if u == 0 {
                 return -1
@@ -803,7 +765,7 @@ public class BitSet: Hashable, CustomStringConvertible {
 
         while true {
             if word != 0 {
-                return (u + 1) * BitSet.BITS_PER_WORD - 1 - BitSet.numberOfLeadingZeros(word)
+                return (u + 1) * BitSet.BITS_PER_WORD - 1 - word.leadingZeroBitCount
             }
             if u == 0 {
                 return -1
@@ -812,38 +774,6 @@ public class BitSet: Hashable, CustomStringConvertible {
             word = ~words[u]
         }
     }
-
-    public static func numberOfLeadingZeros(_ i: Int64) -> Int {
-        // HD, Figure 5-6
-        if i == 0 {
-            return 64
-        }
-        var n: Int32 = 1
-        var x = Int32(i >>> 32)
-        if x == 0 {
-            n += 32
-            x = Int32(i)
-        }
-        if x >>> 16 == 0 {
-            n += 16
-            x <<= 16
-        }
-        if x >>> 24 == 0 {
-            n += 8
-            x <<= 8
-        }
-        if x >>> 28 == 0 {
-            n += 4
-            x <<= 4
-        }
-        if x >>> 30 == 0 {
-            n += 2
-            x <<= 2
-        }
-        n -= x >>> 31
-
-        return Int(n)
-    }
     /// 
     /// Returns the "logical size" of this `BitSet`: the index of
     /// the highest set bit in the `BitSet` plus one. Returns zero
@@ -857,7 +787,7 @@ public class BitSet: Hashable, CustomStringConvertible {
         }
 
         return BitSet.BITS_PER_WORD * (wordsInUse - 1) +
-                (BitSet.BITS_PER_WORD - BitSet.numberOfLeadingZeros(words[wordsInUse - 1]))
+                (BitSet.BITS_PER_WORD - words[wordsInUse - 1].leadingZeroBitCount)
     }
 
     /// 
@@ -897,24 +827,11 @@ public class BitSet: Hashable, CustomStringConvertible {
     public func cardinality() -> Int {
         var sum: Int = 0
         for i in 0..<wordsInUse {
-            sum += BitSet.bitCount(words[i])
+            sum += words[i].nonzeroBitCount
         }
         return sum
     }
 
-    public static func bitCount(_ i: Int64) -> Int {
-        var i = i
-        // HD, Figure 5-14
-        i = i - ((i >>> 1) & 0x5555555555555555)
-        i = (i & 0x3333333333333333) + ((i >>> 2) & 0x3333333333333333)
-        i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0f
-        i = i + (i >>> 8)
-        i = i + (i >>> 16)
-        i = i + (i >>> 32)
-
-        return Int(i) & 0x7f
-    }
-
     /// 
     /// Performs a logical __AND__ of this target bit set with the
     /// argument bit set. This bit set is modified so that each bit in it

runtime/Swift/Sources/Antlr4/misc/IntervalSet.swift

@@ -613,10 +613,7 @@ public class IntervalSet: IntSet, Hashable, CustomStringConvertible {
         for interval in intervals {
             let a = interval.a
             let b = interval.b
-
-            for v in a...b  {
-                values.append(v)
-            }
+            values.append(contentsOf: a...b)
         }
         return values
     }

runtime/Swift/Sources/Antlr4/misc/Utils.swift

@@ -41,7 +41,7 @@ public class Utils {
     }
 
     public static func bitLeftShift(_ n: Int) -> Int64 {
-       return (Int64(1) << Int64(n % 64))
+       return (Int64(1) &<< n)
     }
 
 

runtime/Swift/Sources/Antlr4/misc/utils/CommonUtil.swift

@@ -35,26 +35,15 @@ public func +(lhs: Token, rhs: String) -> String {
 infix operator >>> : BitwiseShiftPrecedence
 
 func >>>(lhs: Int32, rhs: Int32) -> Int32 {
-    let left = UInt32(bitPattern: lhs)
-    let right = UInt32(bitPattern: rhs) % 32
-
-    return Int32(bitPattern: left >> right)
+    return lhs &>> rhs
 }
 
 func >>>(lhs: Int64, rhs: Int64) -> Int64 {
-    let left = UInt64(bitPattern: lhs)
-    let right = UInt64(bitPattern: rhs) % 64
-
-    return Int64(bitPattern: left >> right)
+    return lhs &>> rhs
 }
 
 func >>>(lhs: Int, rhs: Int) -> Int {
-    let numberOfBits: UInt = MemoryLayout<UInt>.size == MemoryLayout<UInt64>.size ? 64 : 32
-
-    let left = UInt(bitPattern: lhs)
-    let right = UInt(bitPattern: rhs) % numberOfBits
-
-    return Int(bitPattern: left >> right)
+    return lhs &>> rhs
 }
 
 func intChar2String(_ i: Int) -> String {
@@ -89,18 +78,3 @@ func toUUID(_ data: [Character], _ offset: Int) -> UUID {
     let mostSigBits: Int64 = toLong(data, offset + 4)
     return UUID(mostSigBits: mostSigBits, leastSigBits: leastSigBits)
 }
-
-func ==<T:Equatable>(_ lhs: [T?], _ rhs: [T?]) -> Bool {
-
-    if lhs.count != rhs.count {
-        return false
-    }
-
-    for i in 0..<lhs.count {
-        if lhs[i] != rhs[i] {
-            return false
-        }
-    }
-
-    return true
-}

runtime/Swift/Sources/Antlr4/tree/Trees.swift

@@ -184,8 +184,7 @@ public class Trees {
     }
 
     public static func descendants(_ t: ParseTree) -> Array<ParseTree> {
-        var nodes: Array<ParseTree> = Array<ParseTree>()
-        nodes.append(t)
+        var nodes: Array<ParseTree> = [t]
 
         let n: Int = t.getChildCount()
         for i in 0..<n {