JSSpecCompiler: Add infrastructure to parse <emu-clause> into AST

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Parser/SpecParser.h

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2023, Dan Klishch <danilklishch@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include "AST/AST.h"
+#include "Forward.h"
+#include "Parser/ParseError.h"
+#include "Parser/Token.h"
+
+namespace JSSpecCompiler {
+class AlgorithmStepList {
+public:
+    static ParseErrorOr<AlgorithmStepList> create(XML::Node::Element const& element);
+
+    Vector<AlgorithmStep> m_steps;
+    Tree m_expression = error_tree;
+};
+
+class AlgorithmStep {
+public:
+    static ParseErrorOr<AlgorithmStep> create(XML::Node const* node);
+
+    ParseErrorOr<Tree> parse();
+
+    Tree m_expression = error_tree;
+    Vector<Token> m_tokens;
+    NullableTree m_substeps;
+    XML::Node const* m_node;
+};
+
+class Algorithm {
+public:
+    static ParseErrorOr<Algorithm> create(XML::Node const* node);
+
+    AlgorithmStepList m_steps;
+    Tree m_tree = error_tree;
+};
+
+class Function {
+public:
+    struct Argument {
+        StringView name;
+    };
+
+    static ParseErrorOr<Function> create(XML::Node const* element);
+
+    ParseErrorOr<void> parse_definition(XML::Node const* element);
+
+    StringView m_section_number;
+    StringView m_id;
+    StringView m_name;
+
+    Vector<Argument> m_arguments;
+    Algorithm m_algorithm;
+};
+
+}