feature: Adds special Number static vars

Author: NeedleInAJayStack

Sources/Haystack/IO/ZincReader.swift

@@ -64,8 +64,8 @@ public class ZincReader {
             case "M": return marker
             case "R": return remove
             case "NA": return na
-            case "NaN": return Number(.nan)
-            case "INF": return Number(.infinity)
+            case "NaN": return Number.nan
+            case "INF": return Number.infinity
             default:
                 throw ZincReaderError.UnexpectedId(id)
             }
@@ -79,7 +79,7 @@ public class ZincReader {
         if cur == .minus, peek == .id, peekVal.equals("INF") {
             try consume(.minus)
             try consume(.id)
-            return Number(-1.0 * .infinity)
+            return Number.negativeInfinity
         }
 
         if cur == .lbracket {

Sources/Haystack/Number.swift

@@ -3,6 +3,16 @@ import Foundation
 public struct Number: Val {
     public static var valType: ValType { .Number }
 
+    public static var infinity: Self {
+        return Number(.infinity)
+    }
+    public static var negativeInfinity: Self {
+        return Number(-1 * .infinity)
+    }
+    public static var nan: Self {
+        return Number(.nan)
+    }
+    
     public let val: Double
     public let unit: String?
 

Tests/HaystackTests/IO/ZincReaderTests.swift

@@ -107,7 +107,7 @@ final class ZincReaderTests: XCTestCase {
                 [Uri("path"), Ref("12cbb082-0c02ae73"), Number(4, unit: "s"), Number(-2.5, unit: "min")],
                 [marker, remove, null, null], // Bin not supported.
                 [Date(year: 2009, month: 12, day: 31), Time(hour: 23, minute: 59, second: 1), Time(hour: 1, minute: 2, second: 3, millisecond: 123), DateTime(year: 2009, month: 2, day: 3, hour: 4, minute: 5, second: 6)],
-                [Number(.infinity), Number(-1 * .infinity), "", Number(.nan)],
+                [Number.infinity, Number.negativeInfinity, "", Number.nan],
                 [Coord(lat: 12, lng: -34), Coord(lat: 0.123, lng: -0.789), Coord(lat: 84.5, lng: -77.45), Coord(lat: -90, lng: 180)],
             ]
         )

Tests/HaystackTests/NumberTests.swift

@@ -72,15 +72,15 @@ final class NumberTests: XCTestCase {
             "4"
         )
         XCTAssertEqual(
-            Number(.infinity).toZinc(),
+            Number.infinity.toZinc(),
             "INF"
         )
         XCTAssertEqual(
-            Number((-1.0 * .infinity)).toZinc(),
+            Number.negativeInfinity.toZinc(),
             "-INF"
         )
         XCTAssertEqual(
-            Number(.nan).toZinc(),
+            Number.nan.toZinc(),
             "NaN"
         )
     }