start work on webconsole with templates

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd_webconsole/inja/token.hpp

@@ -0,0 +1,73 @@
+#ifndef INCLUDE_INJA_TOKEN_HPP_
+#define INCLUDE_INJA_TOKEN_HPP_
+
+#include <string>
+#include <string_view>
+
+namespace inja {
+
+/*!
+ * \brief Helper-class for the inja Lexer.
+ */
+struct Token {
+  enum class Kind {
+    Text,
+    ExpressionOpen,     // {{
+    ExpressionClose,    // }}
+    LineStatementOpen,  // ##
+    LineStatementClose, // \n
+    StatementOpen,      // {%
+    StatementClose,     // %}
+    CommentOpen,        // {#
+    CommentClose,       // #}
+    Id,                 // this, this.foo
+    Number,             // 1, 2, -1, 5.2, -5.3
+    String,             // "this"
+    Plus,               // +
+    Minus,              // -
+    Times,              // *
+    Slash,              // /
+    Percent,            // %
+    Power,              // ^
+    Comma,              // ,
+    Dot,                // .
+    Colon,              // :
+    LeftParen,          // (
+    RightParen,         // )
+    LeftBracket,        // [
+    RightBracket,       // ]
+    LeftBrace,          // {
+    RightBrace,         // }
+    Equal,              // ==
+    NotEqual,           // !=
+    GreaterThan,        // >
+    GreaterEqual,       // >=
+    LessThan,           // <
+    LessEqual,          // <=
+    Unknown,
+    Eof,
+  };
+
+  Kind kind {Kind::Unknown};
+  std::string_view text;
+
+  explicit constexpr Token() = default;
+  explicit constexpr Token(Kind kind, std::string_view text): kind(kind), text(text) {}
+
+  std::string describe() const {
+    switch (kind) {
+    case Kind::Text:
+      return "<text>";
+    case Kind::LineStatementClose:
+      return "<eol>";
+    case Kind::Eof:
+      return "<eof>";
+    default:
+      return static_cast<std::string>(text);
+    }
+  }
+};
+
+} // namespace inja
+
+#endif // INCLUDE_INJA_TOKEN_HPP_