Use a version of json scanner from Foundation source code to load json files (#11)

* Use json scanner from foundation

* Load as complete object

* All JSON loading done by JSON scanner

* Add musl, winsdk etc

* Fix for linux

* Use ContiguousBytes protocol instead of Data

Author: adam-fowler

Sources/JMESPath/Array.swift

@@ -0,0 +1,26 @@
+/// Array storage for JMES
+typealias JMESArray = [Any]
+
+extension JMESArray {
+    /// return if arrays are equal by converting entries to `JMESVariable`
+    func equalTo(_ rhs: JMESArray) -> Bool {
+        guard self.count == rhs.count else { return false }
+        for i in 0..<self.count {
+            guard JMESVariable(from: self[i]) == JMESVariable(from: rhs[i]) else {
+                return false
+            }
+        }
+        return true
+    }
+}
+
+extension Array {
+    /// calculate actual index. Negative indices read backwards from end of array
+    func calculateIndex(_ index: Int) -> Int {
+        if index >= 0 {
+            return index
+        } else {
+            return count + index
+        }
+    }
+}

Sources/JMESPath/Ast.swift

@@ -1,5 +1,5 @@
 /// JMES expression abstract syntax tree
-public indirect enum Ast: Equatable {
+indirect enum Ast: Equatable {
     /// compares two nodes using a comparator
     case comparison(comparator: Comparator, lhs: Ast, rhs: Ast)
     /// if `predicate` evaluates to a truthy value returns result from `then`
@@ -39,7 +39,7 @@ public indirect enum Ast: Equatable {
 }
 
 /// Comparator used in comparison AST nodes
-public enum Comparator: Equatable, JMESSendable {
+public enum Comparator: Equatable, Sendable {
     case equal
     case notEqual
     case lessThan
@@ -66,4 +66,4 @@ public enum Comparator: Equatable, JMESSendable {
 // have to force Sendable conformance as enum `.literal` uses `JMESVariable` which
 // is not necessarily sendable but in the use here it is
 extension Ast: @unchecked Sendable {}
-#endif
+#endif

Sources/JMESPath/Expression.swift

@@ -1,9 +1,13 @@
+#if canImport(FoundationEssentials)
+import FoundationEssentials
+#else
 import Foundation
+#endif
 
 /// JMES Expression
 ///
 /// Holds a compiled JMES expression and allows you to search Json text or a type already in memory
-public struct JMESExpression: JMESSendable {
+public struct JMESExpression: Sendable {
     let ast: Ast
 
     public static func compile(_ text: String) throws -> Self {
@@ -22,8 +26,12 @@ public struct JMESExpression: JMESSendable {
     ///   - runtime: JMES runtime (includes functions)
     /// - Throws: JMESPathError
     /// - Returns: Search result
-    public func search<Value>(json: Data, as: Value.Type = Value.self, runtime: JMESRuntime = .init()) throws -> Value? {
-        try self.search(json: json, runtime: runtime) as? Value
+    public func search<Value>(json: String, as: Value.Type = Value.self, runtime: JMESRuntime = .init()) throws -> Value {
+        let searchResult = try self.search(json: json, runtime: runtime)
+        guard let value = searchResult as? Value else {
+            throw JMESPathError.runtime("Expected \(Value.self)) but got a \(type(of: searchResult))")
+        }
+        return value
     }
 
     /// Search JSON
@@ -34,8 +42,12 @@ public struct JMESExpression: JMESSendable {
     ///   - runtime: JMES runtime (includes functions)
     /// - Throws: JMESPathError
     /// - Returns: Search result
-    public func search<Value>(json: String, as: Value.Type = Value.self, runtime: JMESRuntime = .init()) throws -> Value? {
-        try self.search(json: json, runtime: runtime) as? Value
+    public func search<Value>(json: some ContiguousBytes, as: Value.Type = Value.self, runtime: JMESRuntime = .init()) throws -> Value {
+        let searchResult = try self.search(json: json, runtime: runtime)
+        guard let value = searchResult as? Value else {
+            throw JMESPathError.runtime("Expected \(Value.self)) but got a \(type(of: searchResult))")
+        }
+        return value
     }
 
     /// Search Swift type
@@ -46,9 +58,12 @@ public struct JMESExpression: JMESSendable {
     ///   - runtime: JMES runtime (includes functions)
     /// - Throws: JMESPathError
     /// - Returns: Search result
-    public func search<Value>(object: Any, as: Value.Type = Value.self, runtime: JMESRuntime = .init()) throws -> Value? {
-        let value = try self.search(object: object, runtime: runtime)
-        return value as? Value
+    public func search<Value>(object: Any, as: Value.Type = Value.self, runtime: JMESRuntime = .init()) throws -> Value {
+        let searchResult = try self.search(object: object, runtime: runtime)
+        guard let value = searchResult as? Value else {
+            throw JMESPathError.runtime("Expected \(Value.self)) but got a \(type(of: searchResult))")
+        }
+        return value
     }
 
     /// Search JSON
@@ -58,9 +73,9 @@ public struct JMESExpression: JMESSendable {
     ///   - runtime: JMES runtime (includes functions)
     /// - Throws: JMESPathError
     /// - Returns: Search result
-    public func search(json: Data, runtime: JMESRuntime = .init()) throws -> Any? {
-        let value = try JMESVariable.fromJson(json)
-        return try runtime.interpret(value, ast: self.ast).collapse()
+    public func search(json: String, runtime: JMESRuntime = .init()) throws -> Any? {
+        let value = try JMESJSON.parse(json: json)
+        return try runtime.interpret(JMESVariable(from: value), ast: self.ast).collapse()
     }
 
     /// Search JSON
@@ -70,9 +85,9 @@ public struct JMESExpression: JMESSendable {
     ///   - runtime: JMES runtime (includes functions)
     /// - Throws: JMESPathError
     /// - Returns: Search result
-    public func search(json: String, runtime: JMESRuntime = .init()) throws -> Any? {
-        let value = try JMESVariable.fromJson(json)
-        return try runtime.interpret(value, ast: self.ast).collapse()
+    public func search(json: some ContiguousBytes, runtime: JMESRuntime = .init()) throws -> Any? {
+        let value = try JMESJSON.parse(json: json)
+        return try runtime.interpret(JMESVariable(from: value), ast: self.ast).collapse()
     }
 
     /// Search Swift type

Sources/JMESPath/Functions.swift

@@ -1,5 +1,3 @@
-import Foundation
-
 /// Used to validate arguments of a function before it is run
 public struct FunctionSignature {
     /// Function argument used in function signature to verify arguments
@@ -118,7 +116,7 @@ extension JMESVariable {
 /// let expression = try Expression.compile(myExpression)
 /// let result = try expression.search(json: myJson, runtime: runtime)
 /// ```
-public protocol JMESFunction {
+protocol JMESFunction {
     /// function signature
     static var signature: FunctionSignature { get }
     /// Evaluate function
@@ -310,7 +308,7 @@ struct MapFunction: JMESFunction {
     static func evaluate(args: [JMESVariable], runtime: JMESRuntime) throws -> JMESVariable {
         switch (args[0], args[1]) {
         case (.expRef(let ast), .array(let array)):
-            let results = try array.map { try runtime.interpret(JMESVariable(from: $0), ast: ast).collapse() ?? NSNull() }
+            let results = try array.map { try runtime.interpret(JMESVariable(from: $0), ast: ast).collapse() ?? JMESNull() }
             return .array(results)
         default:
             preconditionFailure()
@@ -665,7 +663,7 @@ struct ToArrayFunction: JMESFunction {
         case .array:
             return args[0]
         default:
-            return .array([args[0].collapse() ?? NSNull()])
+            return .array([args[0].collapse() ?? JMESNull()])
         }
     }
 }

Sources/JMESPath/Interpreter.swift

@@ -1,5 +1,4 @@
-import Foundation
-
+/// Extend runtime with intepret function
 extension JMESRuntime {
     /// Interpret Ast given object to search
     /// - Parameters:
@@ -78,7 +77,7 @@ extension JMESRuntime {
                 for element in array {
                     let currentResult = try interpret(.init(from: element), ast: rhs)
                     if currentResult != .null {
-                        collected.append(currentResult.collapse() ?? NSNull())
+                        collected.append(currentResult.collapse() ?? JMESNull())
                     }
                 }
                 return .array(collected)
@@ -108,7 +107,7 @@ extension JMESRuntime {
             }
             var collected: JMESArray = []
             for node in elements {
-                collected.append(try self.interpret(data, ast: node).collapse() ?? NSNull())
+                collected.append(try self.interpret(data, ast: node).collapse() ?? JMESNull())
             }
             return .array(collected)
 
@@ -119,7 +118,7 @@ extension JMESRuntime {
             var collected: JMESObject = [:]
             for element in elements {
                 let valueResult = try self.interpret(data, ast: element.value)
-                collected[element.key] = valueResult.collapse() ?? NSNull()
+                collected[element.key] = valueResult.collapse() ?? JMESNull()
             }
             return .object(collected)