Rename package to swift-mustache (#27)

* Rename package to swift-mustache

* Update CI

Sources/Mustache/Context.swift

@@ -0,0 +1,115 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Hummingbird server framework project
+//
+// Copyright (c) 2021-2021 the Hummingbird authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See hummingbird/CONTRIBUTORS.txt for the list of Hummingbird authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+/// Context while rendering mustache tokens
+struct MustacheContext {
+    let stack: [Any]
+    let sequenceContext: MustacheSequenceContext?
+    let indentation: String?
+    let inherited: [String: MustacheTemplate]?
+    let contentType: MustacheContentType
+    let library: MustacheLibrary?
+
+    /// initialize context with a single objectt
+    init(_ object: Any, library: MustacheLibrary? = nil) {
+        self.stack = [object]
+        self.sequenceContext = nil
+        self.indentation = nil
+        self.inherited = nil
+        self.contentType = HTMLContentType()
+        self.library = library
+    }
+
+    private init(
+        stack: [Any],
+        sequenceContext: MustacheSequenceContext?,
+        indentation: String?,
+        inherited: [String: MustacheTemplate]?,
+        contentType: MustacheContentType,
+        library: MustacheLibrary? = nil
+    ) {
+        self.stack = stack
+        self.sequenceContext = sequenceContext
+        self.indentation = indentation
+        self.inherited = inherited
+        self.contentType = contentType
+        self.library = library
+    }
+
+    /// return context with object add to stack
+    func withObject(_ object: Any) -> MustacheContext {
+        var stack = self.stack
+        stack.append(object)
+        return .init(
+            stack: stack,
+            sequenceContext: nil,
+            indentation: self.indentation,
+            inherited: self.inherited,
+            contentType: self.contentType,
+            library: self.library
+        )
+    }
+
+    /// return context with indent and parameter information for invoking a partial
+    func withPartial(indented: String?, inheriting: [String: MustacheTemplate]?) -> MustacheContext {
+        let indentation: String? = if let indented {
+            (self.indentation ?? "") + indented
+        } else {
+            self.indentation
+        }
+        let inherits: [String: MustacheTemplate]? = if let inheriting {
+            if let originalInherits = self.inherited {
+                originalInherits.merging(inheriting) { value, _ in value }
+            } else {
+                inheriting
+            }
+        } else {
+            self.inherited
+        }
+        return .init(
+            stack: self.stack,
+            sequenceContext: nil,
+            indentation: indentation,
+            inherited: inherits,
+            contentType: HTMLContentType(),
+            library: self.library
+        )
+    }
+
+    /// return context with sequence info and sequence element added to stack
+    func withSequence(_ object: Any, sequenceContext: MustacheSequenceContext) -> MustacheContext {
+        var stack = self.stack
+        stack.append(object)
+        return .init(
+            stack: stack,
+            sequenceContext: sequenceContext,
+            indentation: self.indentation,
+            inherited: self.inherited,
+            contentType: self.contentType,
+            library: self.library
+        )
+    }
+
+    /// return context with sequence info and sequence element added to stack
+    func withContentType(_ contentType: MustacheContentType) -> MustacheContext {
+        return .init(
+            stack: self.stack,
+            sequenceContext: self.sequenceContext,
+            indentation: self.indentation,
+            inherited: self.inherited,
+            contentType: contentType,
+            library: self.library
+        )
+    }
+}