fix Swift type-checker errors in LsvAnalysis chained closures

cue-ios/CueIOS/Models/LsvAnalysis.swift

@@ -41,22 +41,22 @@ func findExtrema(_ v: [Float], _ iSmooth: [Float], minProminence: Float) -> [(In
         }
     }
 
-    return candidates.filter { (idx, isMax) in
+    var result: [(Int, Bool)] = []
+    for (idx, isMax) in candidates {
         let val = iSmooth[idx]
         let leftSlice = iSmooth[..<idx]
         let rightSlice = iSmooth[(idx + 1)...]
-        let leftBound: Float
-        let rightBound: Float
         if isMax {
-            leftBound = leftSlice.min() ?? val
-            rightBound = rightSlice.min() ?? val
-            return val - max(leftBound, rightBound) >= minProminence
+            let lb = leftSlice.min() ?? val
+            let rb = rightSlice.min() ?? val
+            if val - max(lb, rb) >= minProminence { result.append((idx, isMax)) }
         } else {
-            leftBound = leftSlice.max() ?? val
-            rightBound = rightSlice.max() ?? val
-            return min(leftBound, rightBound) - val >= minProminence
+            let lb = leftSlice.max() ?? val
+            let rb = rightSlice.max() ?? val
+            if min(lb, rb) - val >= minProminence { result.append((idx, isMax)) }
         }
     }
+    return result
 }
 
 /// Detect Q/HQ redox peak in the -100 to +600 mV window.
@@ -75,13 +75,16 @@ func detectQhqPeak(_ points: [LsvPoint]) -> Float? {
 
     let extrema = findExtrema(vVals, smoothed, minProminence: prominence)
 
-    let candidates = extrema
-        .filter { $0.1 && vVals[$0.0] >= -100 && vVals[$0.0] <= 600 }
-        .max(by: { smoothed[$0.0] < smoothed[$1.0] })
-
-    if let (idx, _) = candidates {
-        return vVals[idx]
+    var bestIdx: Int? = nil
+    var bestVal: Float = -.infinity
+    for (idx, isMax) in extrema {
+        guard isMax, vVals[idx] >= -100, vVals[idx] <= 600 else { continue }
+        if smoothed[idx] > bestVal {
+            bestVal = smoothed[idx]
+            bestIdx = idx
         }
+    }
+    if let idx = bestIdx { return vVals[idx] }
     return nil
 }
 
@@ -108,38 +111,33 @@ func deriveClPotentials(_ points: [LsvPoint]) -> ClPotentials {
     let extrema = findExtrema(vVals, smoothed, minProminence: prominence)
 
     // v_free: most prominent cathodic peak (isMax==false) in +300 to -300 mV
-    let freePeak = extrema
-        .filter { !$0.1 && vVals[$0.0] >= -300 && vVals[$0.0] <= 300 }
-        .min(by: { smoothed[$0.0] < smoothed[$1.0] })
-
-    let vFree: Float
-    let vFreeDetected: Bool
-    let freeIdx: Int?
-    if let (idx, _) = freePeak {
+    var vFree: Float = 100
+    var vFreeDetected = false
+    var freeIdx: Int? = nil
+    var freeBest: Float = .infinity
+    for (idx, isMax) in extrema {
+        guard !isMax, vVals[idx] >= -300, vVals[idx] <= 300 else { continue }
+        if smoothed[idx] < freeBest {
+            freeBest = smoothed[idx]
             vFree = vVals[idx]
             vFreeDetected = true
             freeIdx = idx
-    } else {
-        vFree = 100
-        vFreeDetected = false
-        freeIdx = nil
+        }
     }
 
     // v_total: secondary cathodic peak between (vFree-100) and -500, excluding free peak
     let totalHi = vFree - 100
     let totalLo: Float = -500
-    let totalPeak = extrema
-        .filter { !$0.1 && vVals[$0.0] >= totalLo && vVals[$0.0] <= totalHi && $0.0 != freeIdx }
-        .min(by: { smoothed[$0.0] < smoothed[$1.0] })
-
-    var vTotal: Float
-    let vTotalDetected: Bool
-    if let (idx, _) = totalPeak {
+    var vTotal: Float = vFree - 300
+    var vTotalDetected = false
+    var totalBest: Float = .infinity
+    for (idx, isMax) in extrema {
+        guard !isMax, vVals[idx] >= totalLo, vVals[idx] <= totalHi, idx != freeIdx else { continue }
+        if smoothed[idx] < totalBest {
+            totalBest = smoothed[idx]
             vTotal = vVals[idx]
             vTotalDetected = true
-    } else {
-        vTotal = vFree - 300
-        vTotalDetected = false
+        }
     }
     vTotal = max(vTotal, -400)
 
@@ -179,18 +177,30 @@ func detectLsvPeaks(_ points: [LsvPoint]) -> [LsvPeak] {
     }
 
     // largest peak in positive voltage region -> freeCl
-    let freeCl = extrema
-        .filter { $0.1 && vVals[$0.0] >= 0 }
-        .max(by: { smoothed[$0.0] < smoothed[$1.0] })
-    if let (idx, _) = freeCl {
+    var freeClIdx: Int? = nil
+    var freeClVal: Float = -.infinity
+    for (idx, isMax) in extrema {
+        guard isMax, vVals[idx] >= 0 else { continue }
+        if smoothed[idx] > freeClVal {
+            freeClVal = smoothed[idx]
+            freeClIdx = idx
+        }
+    }
+    if let idx = freeClIdx {
         peaks.append(LsvPeak(vMv: vVals[idx], iUa: smoothed[idx], kind: .freeCl))
     }
 
     // largest peak in negative voltage region -> totalCl
-    let totalCl = extrema
-        .filter { $0.1 && vVals[$0.0] < 0 }
-        .max(by: { smoothed[$0.0] < smoothed[$1.0] })
-    if let (idx, _) = totalCl {
+    var totalClIdx: Int? = nil
+    var totalClVal: Float = -.infinity
+    for (idx, isMax) in extrema {
+        guard isMax, vVals[idx] < 0 else { continue }
+        if smoothed[idx] > totalClVal {
+            totalClVal = smoothed[idx]
+            totalClIdx = idx
+        }
+    }
+    if let idx = totalClIdx {
         peaks.append(LsvPeak(vMv: vVals[idx], iUa: smoothed[idx], kind: .totalCl))
     }