make working setScale method on BigDecimal

bastie · Dec 10, 2023 · ec465bd · ec465bd
1 parent c758c48
commit ec465bd
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Showing 2 changed files with 24 additions and 45 deletions.
diff --git a/Sources/JavApi/math/BigDecimal+Java.swift b/Sources/JavApi/math/BigDecimal+Java.swift
@@ -13,54 +13,24 @@ extension java.math.BigDecimal {
   public static let ROUND_DOWN = 1
 
   public func setScale (_ newScale : Int, _ roundingMode : Int) -> java.math.BigDecimal {
-    let before = self.exponent
-    var stringValue = ""
-    if before < 0 { // -2 = to chars after point
-      stringValue = "\(self)"
-
-      // trim to scale
-      var newStringValue = ""
-      var dotPosition = -1
-
-      for char in stringValue {
-        if char == "." { // found
-          dotPosition += 1
-        }
-        else {
-          if dotPosition < 0 { // before dot
-            newStringValue.append(char)
-          }
-          else {
-            if dotPosition * -1 > before { // in the scale
-              newStringValue.append(char)
-            }
-            dotPosition += 1 // next position after dot
-          }
-        }
-        // trimmed
-        stringValue = newStringValue
-      }
-
-    }
-    else { // FIXME: not real implemented
-      stringValue = "\((self as NSDecimalNumber).int64Value)"
-    }
-
-    let result = java.math.BigDecimal (string: stringValue)!
 
-    let roundMode : NSDecimalNumber.RoundingMode = switch (roundingMode) {
-    case 4 /* ROUND_HALF_UP */ : .plain
-    case 0 /* ROUND_UP */ : .up
-    case 1 /* ROUND_DOWN */ : .down
-    default : .bankers // FIXME: Java knows some more
+    var result = self
+    var doubleValue = (self as NSDecimalNumber).doubleValue
+    switch roundingMode {
+    case java.math.BigDecimal.ROUND_DOWN :
+      let string = String(format: "%.\(newScale)f" ,doubleValue)
+      result = java.math.BigDecimal.valueOf(string)!
+    case java.math.BigDecimal.ROUND_UP :
+      var factor = 10
+      for _ in 1..<newScale { factor *= 10 }
+      doubleValue = ceil(doubleValue * Double(factor)) / Double(factor)
+      let string = String(format: "%.\(newScale)f" ,doubleValue)
+      result = java.math.BigDecimal.valueOf(string)!
+    default:
+      fatalError("Please help! Not yet implemented round method.")
+      break;
     }
 
-
-    _ = _BigDecimal.savedRoundMode [result, default: roundMode]
     return result
   }
 }
-
-internal class _BigDecimal {
-  internal static var savedRoundMode : [java.math.BigDecimal: NSDecimalNumber.RoundingMode] = [:]
-}
diff --git a/Tests/JavApiTests/JavApi_math_BigDecimal.swift b/Tests/JavApiTests/JavApi_math_BigDecimal.swift
@@ -30,4 +30,13 @@ final class JavApi_math_BigDecimal_Tests: XCTestCase {
     XCTAssertEqual(VSP1, java.math.BigDecimal.valueOf("2325.00")!)
 
   }
+
+  public func testScale2 () {
+    let pi = java.math.BigDecimal.valueOf(Double.pi)
+    let up = pi.setScale(2, java.math.BigDecimal.ROUND_UP)
+    let down = pi.setScale(2, java.math.BigDecimal.ROUND_DOWN)
+
+    XCTAssertEqual(up, 3.15)
+    XCTAssertEqual(down, 3.14)
+  }
 }