sugar/include/molasses/errors.h

#pragma once
#include "lexer.h"
#include <sstream>
#include <stdexcept>


namespace molasses {
    namespace details {
        template<typename... RestT>
        std::string concatenate_builder_impl(std::stringstream& stream)
            requires(sizeof...(RestT) == 0)
        {
            return stream.str();
        }
        template<typename FirstT, typename... RestT>
        std::string concatenate_builder_impl(std::stringstream& stream, FirstT first, RestT... rest) {
            stream << first;
            return concatenate_builder_impl(stream, rest...);
        }
        template<typename... RestT>
        std::string concatenate_builder(RestT... rest) {
            std::stringstream stream{};
            return concatenate_builder_impl(stream, rest...);
        }
    }

    struct build_system_error : std::runtime_error {
        explicit build_system_error(const std::string& message)
            : std::runtime_error(message) {}
    };

    struct interpreter_error : std::runtime_error {
        explicit interpreter_error(const std::string& message)
            : std::runtime_error(message) {}
    };

    struct parser_error : public std::runtime_error {
        explicit parser_error(const std::string& str)
            : std::runtime_error(str) {}
    };

    struct type_input_error : public parser_error {
        type_input_error()
            : parser_error("Bad type provided") {}
        // TODO: Better error message
    };
    struct value_missing_error : public parser_error {
        value_missing_error()
            : parser_error("Expected value, none provided") {}
        // TODO: Better error message
    };
    struct procedure_stack_error : public parser_error {
        procedure_stack_error()
            : parser_error("Expected the stack to look like the return stack upon completion\n") {}
        // TODO: Better error message
    };
    struct unexpected_token_error : public parser_error {
        unexpected_token_error(const symbol& sym, const std::string& found, const std::string& expected)
            : parser_error(details::concatenate_builder(
                  "Unexpected token encountered\n", "\tAt ", sym.file_name, ":", sym.line, ":", sym.column, "\n",
                  "\tExpected ", expected, "\n", "\tFound ", found, "\n"
              )) {}
    };
    struct expecting_token_error : public parser_error {
        expecting_token_error(const std::string& expected, const std::string& context)
            : parser_error(details::concatenate_builder(
                  "An expected token has not been encountered before the end of the input\n", "\tExpected ", expected,
                  "\n", "\t", context, "\n"
              )) {}
        // TODO: Better error message
    };
    struct unknown_token_error : public parser_error {
        explicit unknown_token_error(const symbol& sym)
            : parser_error(details::concatenate_builder(
                  "An unknown token has been encountered\n", "\tAt ", sym.file_name, ":", sym.line, ":", sym.column,
                  "\n"
              )) {}
        // TODO: Better error message
    };
    struct type_expected_with_modifier_error : public parser_error {
        type_expected_with_modifier_error()
            : parser_error("A type is expected before a modifier") {}
        // TODO: Better error message
    };
}