algorithm updates

Source/Charts/Charts/ChartViewBase.swift

@@ -62,12 +62,9 @@ open class ChartViewBase: NSUIView, ChartDataProvider, AnimatorDelegate
             // calculate how many digits are needed
             setupDefaultFormatter(min: data.yMin, max: data.yMax)
 
-            for set in data
+            for set in data where set.valueFormatter is DefaultValueFormatter
             {
-                if set.valueFormatter is DefaultValueFormatter
-                {
-                    set.valueFormatter = defaultValueFormatter
-                }
+                set.valueFormatter = defaultValueFormatter
             }
 
             // let the chart know there is new data

Source/Charts/Components/AxisBase.swift

@@ -12,6 +12,12 @@
 import Foundation
 import CoreGraphics
 
+extension Sequence {
+    func max<T: Comparable>(by keyPath: KeyPath<Element, T>) -> Element? {
+        self.max { $0[keyPath: keyPath] < $1[keyPath: keyPath] }
+    }
+}
+
 /// Base class for all axes
 @objc(ChartAxisBase)
 open class AxisBase: ComponentBase
@@ -133,19 +139,12 @@ open class AxisBase: ComponentBase
 
     @objc open func getLongestLabel() -> String
     {
-        var longest = ""
-
-        for i in entries.indices
-        {
-            let text = getFormattedLabel(i)
-
-            if longest.count < text.count
-            {
-                longest = text
-            }
-        }
-
-        return longest
+        let longest = entries.indices
+            .lazy
+            .map(getFormattedLabel(_:))
+            .max(by: \.count)
+
+        return longest ?? ""
     }
 
     /// - Returns: The formatted label at the specified index. This will either use the auto-formatter or the custom formatter (if one is set).

Source/Charts/Data/Implementations/Standard/BarChartData.swift

@@ -91,7 +91,6 @@ open class BarChartData: BarLineScatterCandleBubbleChartData
             {
                 fromX += diff
             }
-
         }
 
         notifyDataChanged()

Source/Charts/Data/Implementations/Standard/BarChartDataEntry.swift

@@ -112,6 +112,8 @@ open class BarChartDataEntry: ChartDataEntry
         return _positiveSum
     }
 
+    @objc public var stackSize: Int { yValues?.count ?? 1}
+
     @objc open func calcPosNegSum()
     {
         (_negativeSum, _positiveSum) = _yVals?.reduce(into: (0,0)) { (result, y) in
@@ -207,16 +209,6 @@ open class BarChartDataEntry: ChartDataEntry
     /// - Returns:
     private static func calcSum(values: [Double]?) -> Double
     {
-        guard let values = values
-            else { return 0.0 }
-
-        var sum = 0.0
-
-        for f in values
-        {
-            sum += f
-        }
-
-        return sum
+        values?.reduce(into: 0, +=) ?? 0
     }
 }

Source/Charts/Data/Implementations/Standard/BarChartDataSet.swift

@@ -48,18 +48,17 @@ open class BarChartDataSet: BarLineScatterCandleBubbleChartDataSet, BarChartData
     /// stacks. All values belonging to a stack are calculated separately.
     private func calcEntryCountIncludingStacks(entries: [BarChartDataEntry])
     {
-        _entryCountStacks = 0
-
-        entries.forEach { _entryCountStacks += $0.yValues?.count ?? 1 }
+        _entryCountStacks = entries.lazy
+            .map(\.stackSize)
+            .reduce(into: 0, +=)
     }
 
     /// calculates the maximum stacksize that occurs in the Entries array of this DataSet
     private func calcStackSize(entries: [BarChartDataEntry])
     {
-        for e in entries where (e.yValues?.count ?? 0) > _stackSize
-        {
-            _stackSize = e.yValues!.count
-        }
+        _stackSize = entries.lazy
+            .map(\.stackSize)
+            .max(by: \.self) ?? 1
     }
 
     open override func calcMinMax(entry e: ChartDataEntry)

Source/Charts/Highlight/BarHighlighter.swift

@@ -98,6 +98,7 @@ open class BarHighlighter: ChartHighlighter
     @objc open func getClosestStackIndex(ranges: [Range]?, value: Double) -> Int
     {
         guard let ranges = ranges else { return 0 }
+
         if let stackIndex = ranges.firstIndex(where: { $0.contains(value) }) {
             return stackIndex
         } else {

Source/Charts/Highlight/RadarHighlighter.swift

@@ -22,20 +22,12 @@ open class RadarHighlighter: PieRadarHighlighter
         let highlights = getHighlights(forIndex: index)
 
         let distanceToCenter = Double(chart.distanceToCenter(x: x, y: y) / chart.factor)
-
-        var closest: Highlight?
-        var distance = Double.greatestFiniteMagnitude
-
-        for high in highlights
-        {
-            let cdistance = abs(high.y - distanceToCenter)
-            if cdistance < distance
-            {
-                closest = high
-                distance = cdistance
-            }
+
+        func closestToCenter(lhs: Highlight, rhs: Highlight) -> Bool {
+            abs(lhs.y - distanceToCenter) < abs(rhs.y - distanceToCenter)
         }
-
+
+        let closest = highlights.min(by: closestToCenter(lhs:rhs:))
         return closest
     }
 

Source/Charts/Renderers/BarChartRenderer.swift

@@ -391,12 +391,13 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
             // Create and append the corresponding accessibility element to accessibilityOrderedElements
             if let chart = dataProvider as? BarChartView
             {
-                let element = createAccessibleElement(withIndex: j,
-                                                      container: chart,
-                                                      dataSet: dataSet,
-                                                      dataSetIndex: index,
-                                                      stackSize: stackSize)
-                { (element) in
+                let element = createAccessibleElement(
+                    withIndex: j,
+                    container: chart,
+                    dataSet: dataSet,
+                    dataSetIndex: index,
+                    stackSize: stackSize
+                ) { (element) in
                     element.accessibilityFrame = barRect
                 }
 
@@ -536,8 +537,9 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
                     // if we have stacks
 
                     var bufferIndex = 0
-
-                    for index in 0 ..< Int(ceil(Double(dataSet.entryCount) * animator.phaseX))
+                    let lastIndex = ceil(Double(dataSet.entryCount) * animator.phaseX)
+
+                    for index in 0 ..< Int(lastIndex)
                     {
                         guard let e = dataSet.entryForIndex(index) as? BarChartDataEntry else { continue }
 
@@ -548,19 +550,18 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
                         let x = rect.origin.x + rect.size.width / 2.0
 
                         // we still draw stacked bars, but there is one non-stacked in between
-                        if let vals = vals
+                        if let values = vals
                         {
                             // draw stack values
                             var transformed = [CGPoint]()
 
                             var posY = 0.0
                             var negY = -e.negativeSum
 
-                            for k in vals.indices
+                            for value in values
                             {
-                                let value = vals[k]
-                                var y: Double
-
+                                let y: Double
+
                                 if value == 0.0 && (posY == 0.0 || negY == 0.0)
                                 {
                                     // Take care of the situation of a 0.0 value, which overlaps a non-zero bar
@@ -582,9 +583,9 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
 
                             trans.pointValuesToPixel(&transformed)
 
-                            for (val, transformed) in zip(vals, transformed)
+                            for (value, transformed) in zip(values, transformed)
                             {
-                                let drawBelow = (val == 0.0 && negY == 0.0 && posY > 0.0) || val < 0.0
+                                let drawBelow = (value == 0.0 && negY == 0.0 && posY > 0.0) || value < 0.0
                                 let y = transformed.y + (drawBelow ? negOffset : posOffset)
 
                                 guard viewPortHandler.isInBoundsRight(x) else { break }
@@ -597,7 +598,7 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
                                     drawValue(
                                         context: context,
                                         value: formatter.stringForValue(
-                                            val,
+                                            value,
                                             entry: e,
                                             dataSetIndex: dataSetIndex,
                                             viewPortHandler: viewPortHandler),

Source/Charts/Renderers/BubbleChartRenderer.swift

@@ -45,7 +45,8 @@ open class BubbleChartRenderer: BarLineScatterCandleBubbleRenderer
             accessibleChartElements.append(element)
         }
 
-        for case let (i, set) as (Int, BubbleChartDataSetProtocol) in bubbleData.enumerated() where set.isVisible
+        let sets = bubbleData.dataSets as! [BubbleChartDataSet]
+        for case let (i, set) in zip(sets.indices, sets) where set.isVisible
         {
             drawDataSet(context: context, dataSet: set, dataSetIndex: i)
         }

Source/Charts/Renderers/CombinedChartRenderer.swift

@@ -59,35 +59,30 @@ open class CombinedChartRenderer: NSObject, DataRenderer
                 {
                     _renderers.append(BarChartRenderer(dataProvider: chart, animator: animator, viewPortHandler: viewPortHandler))
                 }
-                break
-
+
             case .line:
                 if chart.lineData !== nil
                 {
                     _renderers.append(LineChartRenderer(dataProvider: chart, animator: animator, viewPortHandler: viewPortHandler))
                 }
-                break
-
+
             case .candle:
                 if chart.candleData !== nil
                 {
                     _renderers.append(CandleStickChartRenderer(dataProvider: chart, animator: animator, viewPortHandler: viewPortHandler))
                 }
-                break
-
+
             case .scatter:
                 if chart.scatterData !== nil
                 {
                     _renderers.append(ScatterChartRenderer(dataProvider: chart, animator: animator, viewPortHandler: viewPortHandler))
                 }
-                break
-
+
             case .bubble:
                 if chart.bubbleData !== nil
                 {
                     _renderers.append(BubbleChartRenderer(dataProvider: chart, animator: animator, viewPortHandler: viewPortHandler))
                 }
-                break
             }
         }
 
@@ -190,10 +185,7 @@ open class CombinedChartRenderer: NSObject, DataRenderer
     /// e.g. if you provide [DrawOrder.Bar, DrawOrder.Line], the bars will be drawn behind the lines.
     open var drawOrder: [CombinedChartView.DrawOrder]
     {
-        get
-        {
-            return _drawOrder
-        }
+        get { _drawOrder }
         set
         {
             if !newValue.isEmpty