1 files changed, 80 insertions, 6 deletions

diff --git a/src/core/CSSParser.hpp b/src/core/CSSParser.hpp
index 4c99a5a..c1a4c0d 100644
--- a/src/core/CSSParser.hpp
+++ b/src/core/CSSParser.hpp
@@ -19,24 +19,98 @@
 #ifndef _OUSIA_CSS_PARSER_HPP_
 #define _OUSIA_CSS_PARSER_HPP_
 
-#include <istream>
-#include <map>
 #include <vector>
 #include <tuple>
 
 #include "BufferedCharReader.hpp"
-#include "Managed.hpp"
-#include "Node.hpp"
 #include "CSS.hpp"
+#include "Exceptions.hpp"
 
 namespace ousia {
 
+/**
+ * This is a context free, recursive parser for a subset of the CSS3 language
+ * as defined by W3C. We allow the following grammar:
+ *
+ * DOC              := SELECT RULESET DOC | epsilon
+ * SELECTORS        := SELECT , SELECTORS | SELECT
+ * SELECT           := SELECT' OPERATOR SELECT | SELECT'
+ * SELECT'          := TYPE | TYPE:PSEUDO | TYPE::GEN_PSEUDO |
+ *                     TYPE:PSEUDO(ARGUMENTS) |
+ *                     TYPE::GEN_PSEUDO(ARGUMENTS) | TYPE#ID |
+ *                     TYPE[ATTRIBUTE] | TYPE[ATTRIBUTE=VALUE]
+ * TYPE             := string
+ * PSEUDO           := string
+ * GEN_PSEUDO       := string
+ * ARGUMENTS        := string , ARGUMENTS
+ * ID               := string
+ * ATTRIBUTE        := string
+ * VALUE            := string
+ * OPERATOR         := epsilon | &gt;
+ * RULESET          := epsilon | { RULES }
+ * RULES            := RULE RULES | epsilon
+ * RULE             := KEY : VALUE ;
+ * KEY              := string
+ * VALUE            := type-specific parser
+ *
+ *
+ * @author Benjamin Paassen - bpaassen@techfak.uni-bielefeld.de
+ */
 class CSSParser {
-
 private:
+	/**
+	 * Implements the DOC Nonterminal
+	 */
+	void parseDocument(Rooted<SelectorNode> root, CodeTokenizer &tokenizer);
+	/**
+	 * Implements the SELECTORS Nonterminal and adds all leaf nodes of the
+	 * resulting SelectorTree to the input leafList so that a parsed RuleSet can
+	 * be inserted there.
+	 */
+	void parseSelectors(Rooted<SelectorNode> root, CodeTokenizer &tokenizer,
+	                    std::vector<Rooted<SelectorNode>> &leafList);
+	/**
+	 * Implements the SELECT Nonterminal, which in effect parses a SelectorPath
+	 * of the SelectorTree and returns the beginning node of the path as first
+	 * element as well as the leaf of the path as second tuple element.
+	 */
+	std::tuple<Rooted<SelectorNode>, Rooted<SelectorNode>> parseSelector(
+	    CodeTokenizer &tokenizer);
+
+	/**
+	 * Implements the SELECT' Nonterminal, which parses a single Selector with
+	 * its PseudoSelector and returns it.
+	 */
+	Rooted<SelectorNode> parsePrimitiveSelector(CodeTokenizer &tokenizer);
+
+	// TODO: Add RuleSet parsing methods.
+
+	/**
+	 * A convenience function to wrap around the tokenizer peek() function that
+	 * only returns true if an instance of the expected type occurs.
+	 *
+	 * @param expectedType the ID of the expected type according to the
+	 *                     CodeTokenizer specification.
+	 * @param tokenizer    the tokenizer for the input.
+	 * @param t            an empty token that gets the parsed token content
+	 *                     if it has the expected type.
+	 * @param force        a flag to be set if it would be fatal for the
+	 *                     parsing process to get the wrong type. In that case
+	 *                     an exception is thrown.
+	 * @return             true iff a token of the expected type was found.
+	 */
+	bool expect(int expectedType, CodeTokenizer &tokenizer, Token &t,
+	            bool force);
 
 public:
-	StyleNode parse(BufferedCharReader &input);
+	/**
+	 * This parses the given input as CSS content as specified by the grammar
+	 * seen above. The return value is a Rooted reference to the root of the
+	 * SelectorTree.
+	 * TODO: The RuleSet at the respective node at the tree lists all CSS Style
+	 * rules that apply.
+	 */
+	Rooted<SelectorNode> parse(BufferedCharReader &input);
 };
 }