Interface to the Problems module.

§1. 

define PROBLEMS_HTML_EMITTER HTMLFiles::char_out

§2. Inform tops and tails its output of problem messages, and it also prints non-problem messages when everything was fine. That all happens here: 

define PROBLEMS_INITIAL_REPORTER Problems::Using::start_problems_report
define PROBLEMS_FINAL_REPORTER Problems::Using::final_report

void Problems::Using::start_problems_report(filename *F) {
    if (STREAM_OPEN_TO_FILE(problems_file, F, UTF8_ENC) == FALSE)
        Problems::Fatal::filename_related("Can't open problem log", F);
    HTMLFiles::html_header(problems_file, I"Translating the Source");
}

void Problems::Using::final_report(int disaster_struck, int problems_count) {
    int total_words = 0;

    if (problem_count > 0) {
        Problems::Buffer::redirect_problem_stream(problems_file);
        Problems::issue_problem_begin(Task::syntax_tree(), "*");
        if (disaster_struck) Issue problem summary for an internal error2.1
        else Issue problem summary for a run with problem messages2.2;
        Problems::issue_problem_end();
        Problems::Buffer::redirect_problem_stream(NULL);
    } else {
        int rooms = 0, things = 0;
        HTMLFiles::html_outcome_image(problems_file, "ni_succeeded", "Succeeded");
        #ifdef IF_MODULE
        PL::Spatial::get_world_size(&rooms, &things);
        #endif
        Problems::quote_number(1, &rooms);
        if (rooms == 1) Problems::quote_text(2, "room"); else Problems::quote_text(2, "rooms");
        Problems::quote_number(3, &things);
        if (things == 1) Problems::quote_text(4, "thing"); else Problems::quote_text(4, "things");
        total_words = TextFromFiles::total_word_count(FIRST_OBJECT(source_file));
        Problems::quote_number(5, &total_words);
        Issue problem summaries for a run without problems2.3;
    }
}

§2.1. One of the slightly annoying things about internal errors is that Inform's users persistently refer to them as "crashes" on bug report forms. I mean, the effort we go to! They are entirely clean exits from the program! The ingratitude of some — oh, all right.

Issue problem summary for an internal error2.1 = 

    Problems::issue_problem_segment(
        "What has happened here is that one of the checks Inform carries "
        "out internally, to see if it is working properly, has failed. "
        "There must be a bug in this copy of Inform. It may be worth "
        "checking whether you have the current, up-to-date version. "
        "If so, please report this problem via www.inform7.com/bugs. %P"
        "As for fixing your source text to avoid this bug, the last thing "
        "you changed is probably the cause, if there is a simple cause. "
        "Your source text might in fact be wrong, and the problem might be "
        "occurring because Inform has failed to find a good way to say so. "
        "But even if your source text looks correct, there are "
        "probably rephrasings which would achieve the same effect.");

§2.2. Singular and plural versions of the same message, really:

Issue problem summary for a run with problem messages2.2 = 

    if (problem_count == 1)
        Problems::issue_problem_segment(
            "Because of this problem, the source could not be translated "
            "into a working game. (Correct the source text to "
            "remove the difficulty and click on Go once again.)");
    else
        Problems::issue_problem_segment(
            "Problems occurring in translation prevented the game "
            "from being properly created. (Correct the source text to "
            "remove these problems and click on Go once again.)");
    HTMLFiles::outcome_image_tail(problems_file);

    text_stream *STATUS = ProgressBar::begin_outcome();
    if (STATUS) {
        WRITE_TO(STATUS, "Translation failed: %d problem%s found",
            problem_count, (problem_count==1)?"":"s");
        ProgressBar::end_outcome();
    }

§2.3. The success message needs to take different forms in stdout and in the Problems log file. In the latter, we write as though the subsequent conversion of Inform's output to a story file via Inform 6 had already been completed successfully — this is because the Problems log is intended to be viewed inside the Inform application, which will instead divert to an error page if I6 should fail. So although the Problems file contains an unwarranted claim, if not an actual falsehood, no human eye should see it unless and until it comes true.

We don't want to make similar claims on stdout, where the user — who might well not be running in the Inform application, but only on the command line — deserves the truth.

Issue problem summaries for a run without problems2.3 = 

    Problems::Buffer::redirect_problem_stream(problems_file);
    text_stream *OUT = problems_file;
    HTML_OPEN("p");
    Problems::issue_problem_begin(Task::syntax_tree(), "**");
    Problems::issue_problem_segment(
        "The %5-word source text has successfully been translated "
        "into a world with %1 %2 and %3 %4, and the index has been "
        "brought up to date.");
    Problems::issue_problem_end();
    HTMLFiles::outcome_image_tail(problems_file);

    if (telemetry_recording) {
        Telemetry::ensure_telemetry_file();
        Problems::Buffer::redirect_problem_stream(telmy);
        Problems::issue_problem_begin(Task::syntax_tree(), "**");
        Problems::issue_problem_segment(
            "The %5-word source text has successfully been translated "
            "into a world with %1 %2 and %3 %4, and the index has been "
            "brought up to date.");
        Problems::issue_problem_end();
        WRITE_TO(telmy, "\n");
    }
    Problems::Buffer::redirect_problem_stream(STDOUT);
    WRITE_TO(STDOUT, "\n");
    Problems::issue_problem_begin(Task::syntax_tree(), "**");
    Problems::issue_problem_segment(
        "The %5-word source text has successfully been translated "
        "into an intermediate description which can be run through "
        "Inform 6 to complete compilation. There were %1 %2 and %3 %4.");
    Problems::issue_problem_end();
    STREAM_FLUSH(STDOUT);
    Problems::Buffer::redirect_problem_stream(NULL);

    ProgressBar::final_state_of_progress_bar();
    text_stream *STATUS = ProgressBar::begin_outcome();
    if (STATUS) {
        WRITE_TO(STATUS, "Translation succeeded: %d room%s, %d thing%s",
            rooms, (rooms==1)?"":"s",
            things, (things==1)?"":"s");
        ProgressBar::end_outcome();
    }