Runtime Work

Signed-off-by: Will Hawkins <hawkinsw@obs.cr>

Sources/P4/Program.swift

@@ -1,4 +1,71 @@
-public struct Program {
+public class Identifier: CustomStringConvertible {
+    var name: String
+    var value: Value
+
+    public init(name: String, withValue value: Value) {
+        self.name = name
+        self.value = value
+    }
+
+    public var description: String {
+        return "\(name) = \(value)"
+    }
+}
+
+public class Variable: Identifier {
+    var constant: Bool
+
+    public init(name: String, withValue value: Value, isConstant constant: Bool) {
+        self.constant = constant
+        super.init(name: name, withValue: value)
+    }
+
+    public override var description: String {
+        return "\(super.description) \(constant ? "(constant)" : "")"
+    }
+}
+
+public struct Scope: CustomStringConvertible{
+    var variables: [Variable] = Array()
+    public init() {}
+
+    public var description: String {
+        var result = String()
+        for v in variables {
+            result += "\(v)"
+        }
+        return result
+    }
+}
+
+public struct Scopes: CustomStringConvertible {
+    var scopes: [Scope] = Array()
+
+    public init() {}
+
+    public mutating func enter() {
+        scopes.append(Scope())
+    }
+
+    public mutating func exit() {
+        let _ = scopes.popLast()
+    }
+
+    public var description: String {
+        var result = String()
+        for s in scopes {
+            result += "Scope: \(s)\n"
+        }
+
+        return result
+    }
+}
+
+public struct Program: CustomStringConvertible {
     public var parsers: [P4.Parser] = Array()
-    public init() { }
-}
+    public init() {}
+
+    public var description: String {
+        return "Program"
+    }
+}