Add requirement-based resolution to index

Sources/apk/Index/ApkIndex.swift

@@ -7,6 +7,7 @@ import Foundation
 
 public struct ApkIndex: Sendable {
   public let packages: [ApkIndexPackage]
+  public typealias Index = Array<ApkIndexPackage>.Index
 }
 
 public extension ApkIndex {
@@ -21,6 +22,18 @@ public extension ApkIndex {
       $0.name == name
     }
   }
+
+  func resolve(requirement: ApkVersionRequirement) -> ApkIndexPackage? {
+    self.packages.first {
+      $0.name == requirement.name && requirement.versionSpec.satisfied(by: $0.version)
+    }
+  }
+
+  func resolveIndex(requirement: ApkVersionRequirement) -> Index? {
+    self.packages.firstIndex {
+      $0.name == requirement.name && requirement.versionSpec.satisfied(by: $0.version)
+    }
+  }
 }
 
 public extension ApkIndex {

Sources/apk/Version/ApkVersionRequirement.swift

@@ -5,7 +5,7 @@
 
 import Foundation
 
-internal struct ApkVersionRequirement: Sendable, Hashable {
+public struct ApkVersionRequirement: Sendable, Hashable {
   let name: String
   let versionSpec: ApkVersionSpecification
 
@@ -49,7 +49,7 @@ internal struct ApkVersionRequirement: Sendable, Hashable {
 }
 
 extension ApkVersionRequirement: CustomStringConvertible {
-  var description: String {
+  public var description: String {
     switch self.versionSpec {
     case .any(let invert):
       "\(invert ? "!" : "")\(self.name)"

Sources/apk/Version/ApkVersionSpecification.swift

@@ -30,6 +30,51 @@ internal extension ApkVersionSpecification {
       return false
     }
   }
+
+  func satisfied(by version: String) -> Bool {
+    switch self {
+    case .any:
+      //return true
+      return ApkVersionCompare.validate(version)
+    case .constraint(_ , let op, let requiredVersion):
+      switch ApkVersionCompare.compare(version, requiredVersion, mode: op.isFuzzy ? .fuzzy : .normal) {
+      case .equal:   return op.isEqual
+      case .greater: return op.isGreater
+      case .less:    return op.isLess
+      default: return false
+      }
+    }
+  }
+}
+
+internal extension ApkVersionSpecification.Operator {
+  @inlinable var isFuzzy: Bool {
+    switch self {
+    case .fuzzyEquals, .lessFuzzy, .greaterFuzzy: return true
+    default: return false
+    }
+  }
+
+  @inlinable var isEqual: Bool {
+    switch self {
+    case .equals, .fuzzyEquals, .greaterEqual, .lessEqual, .greaterFuzzy, .lessFuzzy: true
+    default: false
+    }
+  }
+
+  @inlinable var isGreater: Bool {
+    switch self {
+    case .greater, .greaterEqual, .greaterFuzzy: true
+    default: false
+    }
+  }
+
+  @inlinable var isLess: Bool {
+    switch self {
+    case .less, .lessEqual, .lessFuzzy: true
+    default: false
+    }
+  }
 }
 
 extension ApkVersionSpecification.Operator: CustomStringConvertible {