Work on parser

docs/html_grammar.txt

@@ -5,7 +5,7 @@ Defined Tokens
 
 ---
 
-<doc> ::= [<doctype>] <elem>
+<doc> ::= [<doctype>] <elem>*
 <doctype> ::= "<" "!" "doctype" "html" ">"
 <elem> ::=
     | "<" <ident> <attr>* ">" (<elem> | <inner>)* "<" "/" <ident> ">"

src/html_parse.cpp

@@ -182,4 +182,94 @@ std::string Token::to_string()
     }
 }
 
+Parser::Parser(std::vector<Token> tokens)
+    : m_tokens(std::move(tokens))
+    , m_index(0)
+{
+}
+
+NodeDoc Parser::parse()
+{
+    return {};
+}
+
+std::optional<std::reference_wrapper<Token>> Parser::peek(size_t ahead)
+{
+    if (m_index + ahead >= m_tokens.size()) {
+        return {};
+    }
+    return m_tokens.at(m_index + ahead);
+}
+Token& Parser::consume()
+{
+    return m_tokens.at(m_index++);
+}
+
+bool is_ci_equal(const std::string& s1, const std::string& s2)
+{
+    if (s1.size() != s2.size()) {
+        return false;
+    }
+    for (size_t i = 0; i < s1.size(); i++) {
+        if (std::tolower(s1.at(i) != std::tolower(s2.at(i)))) {
+            return false;
+        }
+    }
+    return true;
+}
+
+std::optional<NodeDocType> Parser::parse_doc_type()
+{
+    if (!peek().has_value()) {
+        return {};
+    }
+    Token& ahead1 = peek().value().get();
+    if (ahead1.type != TokenType::lt) {
+        return {};
+    }
+    if (!peek(2).has_value()) {
+        return {};
+    }
+    Token& ahead2 = peek(2).value().get();
+    if (ahead2.type != TokenType::ident || !ahead2.value.has_value() || !is_ci_equal(ahead2.value.value(), "doctype")) {
+        return {};
+    }
+    consume();
+    consume();
+    Token& ahead3 = peek(3).value().get();
+    if (ahead3.type != TokenType::ident) {
+        std::cerr << "[ERROR] Expected identifier" << std::endl;
+        exit(EXIT_FAILURE);
+    }
+    NodeDocType doc_type;
+    doc_type.type = consume().value.value();
+}
+bool Parser::peek_is(size_t ahead, TokenType type)
+{
+    if (!peek(ahead).has_value()) {
+        return {};
+    }
+    return peek(ahead).value().get().type == type;
+}
+
+bool Parser::peek_is_with_val(size_t ahead, TokenType type)
+{
+    if (!peek_is(ahead, type)) {
+        return false;
+    }
+    return peek(ahead).value().get().value.has_value();
+}
+bool Parser::peek_is(size_t ahead, TokenType type, const std::string& val, Parser::StrCmp cmp)
+{
+    if (!peek_is_with_val(ahead, type)) {
+        return false;
+    }
+    switch (cmp) {
+    case StrCmp::case_sensitive:
+        return peek(ahead).value().get().value.value() == val;
+    case StrCmp::case_insensitive:
+        return is_ci_equal(peek(ahead).value().get().value.value(), val);
+    }
+}
+
 }

src/html_parse.hpp

@@ -1,7 +1,9 @@
 #pragma once
 
+#include <memory>
 #include <optional>
 #include <string>
+#include <variant>
 #include <vector>
 
 #include <utf8.h>
@@ -37,12 +39,6 @@ struct Token {
     std::string to_string();
 };
 
-enum class NodeType {
-
-};
-
-struct Node { };
-
 class Tokenizer {
 public:
     explicit Tokenizer(std::string source);
@@ -53,4 +49,62 @@ private:
     std::string m_source;
 };
 
+struct NodeDocType {
+    std::string type;
+};
+
+struct NodeAttr {
+    std::string key;
+    std::string val;
+};
+
+struct NodeInner {
+    std::string value;
+};
+
+struct NodeElem;
+
+struct NodeElemReg {
+    std::string tag;
+    std::vector<NodeAttr> attributes;
+    std::vector<std::variant<NodeElem, NodeInner>> inner;
+};
+
+struct NodeElemSelfClose {
+    std::string tag;
+    std::vector<NodeAttr> attributes;
+};
+
+struct NodeElem {
+    std::variant<NodeElemReg, NodeElemSelfClose> var;
+};
+
+struct NodeDoc {
+    std::optional<NodeDocType> doc_type;
+    std::vector<NodeElem> children;
+};
+
+class Parser {
+public:
+    explicit Parser(std::vector<Token> tokens);
+
+    NodeDoc parse();
+
+    std::optional<NodeDocType> parse_doc_type();
+
+private:
+    std::optional<std::reference_wrapper<Token>> peek(size_t ahead = 0);
+
+    enum class StrCmp { case_sensitive, case_insensitive };
+
+    bool peek_is(size_t ahead, TokenType type);
+    bool peek_is_with_val(size_t ahead, TokenType type);
+    bool peek_is(size_t ahead, TokenType type, const std::string& val, StrCmp cmp);
+
+    Token& consume();
+
+    std::vector<Token> m_tokens;
+    size_t m_index;
+};
+
 }