To manage the special variables providing bibliographic data on the work of IF being generated (title, author's name and so forth), and to write the Library Card in the index.
§2. Much of this section is best understood by reference to the Treaty of Babel, a cross-IF-system standard for bibliographic data and packaging agreed between the major IF design systems in 2006. Inform aims to comply fully with the Treaty and the code below should be maintained as such.
The bibliographic data for the story is kept in the following variables, which are used to build the iFiction record and the releasing blurb at the end of a successful compilation.
nonlocal_variable *story_title_VAR = NULL; nonlocal_variable *story_author_VAR = NULL; nonlocal_variable *story_headline_VAR = NULL; nonlocal_variable *story_genre_VAR = NULL; nonlocal_variable *story_description_VAR = NULL; nonlocal_variable *story_release_number_VAR = NULL; nonlocal_variable *story_creation_year_VAR = NULL; int episode_number = -1; for a work which is part of a numbered series wchar_t *series_name = NULL;
§3. This is organised as a plugin since it's all broadly IF-based, and not something you'd expect in a general programming language. But the main effect is only to make a small number of variables special.
void PL::Bibliographic::start(void) { PLUGIN_REGISTER(PLUGIN_NEW_VARIABLE_NOTIFY, PL::Bibliographic::bibliographic_new_variable_notify); }
§4. The following grammar contains the names of all of the bibliographic variables — those used to set entries on the Library Card about a project. As usual, Inform uses these English wordings to detect the creation of the variables in the Standard Rules, which are in English: so there's no point in translating this nonterminal to other languages.
<notable-bibliographic-variables> ::= story title | story author | story headline | story genre | story description | story creation year | release number
- This is Preform grammar, not regular C code.
define STORY_TITLE_BIBV 0 define STORY_AUTHOR_BIBV 1 define STORY_HEADLINE_BIBV 2 define STORY_GENRE_BIBV 3 define STORY_DESCRIPTION_BIBV 4 define STORY_CREATION_YEAR_BIBV 5 define RELEASE_NUMBER_BIBV 6
int PL::Bibliographic::bibliographic_new_variable_notify(nonlocal_variable *q) { if (<notable-bibliographic-variables>(q->name)) { switch (<<r>>) { case STORY_TITLE_BIBV: story_title_VAR = q; break; case STORY_AUTHOR_BIBV: story_author_VAR = q; break; case STORY_HEADLINE_BIBV: story_headline_VAR = q; break; case STORY_GENRE_BIBV: story_genre_VAR = q; break; case STORY_DESCRIPTION_BIBV: story_description_VAR = q; break; case STORY_CREATION_YEAR_BIBV: story_creation_year_VAR = q; break; case RELEASE_NUMBER_BIBV: story_release_number_VAR = q; break; } NonlocalVariables::make_constant(q, TRUE); } return FALSE; }
§6. The following is called in response to the bibliographic sentence. That in fact has already been parsed by Inbuild, so we simply extract the results, and set the "story title" and "story author" variables accordingly.
void PL::Bibliographic::bibliographic_data(parse_node *PN) { inbuild_edition *edn = Task::edition(); TEMPORARY_TEXT(T) TEMPORARY_TEXT(A) WRITE_TO(T, "\"%S\" ", edn->work->title); WRITE_TO(A, "\"%S\" ", edn->work->author_name); wording TW = Feeds::feed_text(T); wording AW = Feeds::feed_text(A); DISCARD_TEXT(T) DISCARD_TEXT(A) if ((story_title_VAR) && (story_author_VAR)) { parse_node *the_title; if (<s-value>(TW)) the_title = <<rp>>; else the_title = Specifications::new_UNKNOWN(TW); Assertions::PropertyKnowledge::initialise_global_variable(story_title_VAR, the_title); Strings::TextLiterals::suppress_quote_expansion(Node::get_text(the_title)); if (Str::len(edn->work->author_name) > 0) { parse_node *the_author; if (<s-value>(AW)) the_author = <<rp>>; else the_author = Specifications::new_UNKNOWN(AW); Assertions::PropertyKnowledge::initialise_global_variable(story_author_VAR, the_author); } } }
§7. This unattractive routine performs a string comparison of the author's name against one that's supplied, case sensitively, and is used when deciding whether to print credits at run-time for extensions written by the same person as the author of the main work.
int PL::Bibliographic::story_author_is(text_stream *p) { if ((story_author_VAR) && (NonlocalVariables::has_initial_value_set(story_author_VAR))) { parse_node *spec = NonlocalVariables::get_initial_value(story_author_VAR); Node::set_kind_of_value(spec, K_text); int result = FALSE; TEMPORARY_TEXT(TEMP) wording W = Node::get_text(spec); int w1 = Wordings::first_wn(W); PL::Bibliographic::compile_bibliographic_text(TEMP, Lexer::word_text(w1)); if (Str::eq(TEMP, p)) result = TRUE; DISCARD_TEXT(TEMP) return result; } return FALSE; }
§8. Inform probably shouldn't support this sentence, which does nothing other than to fill in two pieces of rarely-used bibliographic data (which could just as easily be variables). But two of the larger worked examples we were trying Inform out on, in the early days, belonged to a sequence called "When in Rome". So it didn't seem such an obscure request at the time.
This is episode 2 of "When in Rome".
The subject noun phrase is fixed, so the information is in the object NP, which must match:
<episode-sentence-subject> ::= <definite-article> story | this story | story <episode-sentence-object> ::= episode <cardinal-number> of <quoted-text-without-subs> | ==> R[1]; <<series>> = R[2]; episode ... ==> Issue PM_BadEpisode problem8.1;
- This is Preform grammar, not regular C code.
§8.1. Issue PM_BadEpisode problem8.1 =
*X = -1; StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_BadEpisode), "this is not the right way to specify how the story " "fits into a larger narrative", "and should take the form 'The story is episode 2 of " "\"Belt of Orion\", where the episode number has to be a " "whole number 0, 1, 2, ... and the series name has to be " "plain text without [substitutions].");
- This code is used in §8.
§9. This handles the special meaning "The story is episode...".
int PL::Bibliographic::episode_SMF(int task, parse_node *V, wording *NPs) { wording SW = (NPs)?(NPs[0]):EMPTY_WORDING; wording OW = (NPs)?(NPs[1]):EMPTY_WORDING; switch (task) { "The story is episode 2 of ..." case ACCEPT_SMFT: if ((<episode-sentence-subject>(SW)) && (<episode-sentence-object>(OW))) { Annotations::write_int(V, verb_id_ANNOT, SPECIAL_MEANING_VB); if (<<r>> >= 0) { episode_number = <<r>>; Word::dequote(<<series>>); series_name = Lexer::word_text(<<series>>); } return TRUE; } break; } return FALSE; }
§10. In the I6 template layer, some of the bibliographic variables are actually compiled to constants, used early on at run-time to print the banner.
void PL::Bibliographic::compile_constants(void) { encode_constant_text_bibliographically = TRUE; BEGIN_COMPILATION_MODE; COMPILATION_MODE_ENTER(COMPILE_TEXT_TO_I6_CMODE); if (story_title_VAR) Compile the I6 Story constant10.1; if (story_headline_VAR) Compile the I6 Headline constant10.2; if (story_author_VAR) Compile the I6 Story Author constant10.3; if (story_release_number_VAR) Compile the I6 Release directive10.4; Compile the I6 serial number, based on the date10.5; END_COMPILATION_MODE; encode_constant_text_bibliographically = FALSE; }
§10.1. If the author doesn't name a work, then its title is properly "", not "Welcome": that's just something we use to provide a readable banner.
Compile the I6 Story constant10.1 =
inter_name *iname = Hierarchy::find(STORY_HL); NonlocalVariables::treat_as_plain_text_word(story_title_VAR); inter_t v1 = 0, v2 = 0; if (NonlocalVariables::has_initial_value_set(story_title_VAR)) NonlocalVariables::seek_initial_value(iname, &v1, &v2, story_title_VAR); else Strings::TextLiterals::compile_literal_from_text(iname, &v1, &v2, L"\"Welcome\""); Emit::named_generic_constant(iname, v1, v2); Hierarchy::make_available(Emit::tree(), iname);
- This code is used in §10.
Compile the I6 Headline constant10.2 =
inter_name *iname = Hierarchy::find(HEADLINE_HL); inter_t v1 = 0, v2 = 0; if (NonlocalVariables::has_initial_value_set(story_headline_VAR)) { NonlocalVariables::treat_as_plain_text_word(story_headline_VAR); NonlocalVariables::seek_initial_value(iname, &v1, &v2, story_headline_VAR); } else { Strings::TextLiterals::compile_literal_from_text(iname, &v1, &v2, L"\"An Interactive Fiction\""); } Emit::named_generic_constant(iname, v1, v2); Hierarchy::make_available(Emit::tree(), iname);
- This code is used in §10.
§10.3. This time we compile nothing if no author is provided:
Compile the I6 Story Author constant10.3 =
if (NonlocalVariables::has_initial_value_set(story_author_VAR)) { inter_name *iname = Hierarchy::find(STORY_AUTHOR_HL); inter_t v1 = 0, v2 = 0; NonlocalVariables::treat_as_plain_text_word(story_author_VAR); NonlocalVariables::seek_initial_value(iname, &v1, &v2, story_author_VAR); Emit::named_generic_constant(iname, v1, v2); Hierarchy::make_available(Emit::tree(), iname); UseOptions::story_author_given(); } else { inter_name *iname = Hierarchy::find(STORY_AUTHOR_HL); inter_t v1 = LITERAL_IVAL, v2 = 0; Emit::named_generic_constant(iname, v1, v2); Hierarchy::make_available(Emit::tree(), iname); }
- This code is used in §10.
§10.4. Similarly (but numerically):
Compile the I6 Release directive10.4 =
if (NonlocalVariables::has_initial_value_set(story_release_number_VAR)) { inter_name *iname = Hierarchy::find(RELEASE_HL); inter_t v1 = 0, v2 = 0; NonlocalVariables::seek_initial_value(iname, &v1, &v2, story_release_number_VAR); Emit::named_generic_constant(iname, v1, v2); Hierarchy::make_available(Emit::tree(), iname); }
- This code is used in §10.
§10.5. This innocuous code — if Inform runs on 25 June 2013, we compile the serial number "130625" — is actually controversial: quite a few users feel they should be able to fake the date-stamp with dates of their own choosing.
Compile the I6 serial number, based on the date10.5 =
inter_name *iname = Hierarchy::find(SERIAL_HL); TEMPORARY_TEXT(SN) int year_digits = (the_present->tm_year) % 100; WRITE_TO(SN, "%02d%02d%02d", year_digits, (the_present->tm_mon)+1, the_present->tm_mday); Emit::named_text_constant(iname, SN); DISCARD_TEXT(SN) Hierarchy::make_available(Emit::tree(), iname);
- This code is used in §10.
§11. The Library Card is part of the Contents index, and is intended as a natural way to present bibliographic data to the user. In effect, it's a simplified form of the iFiction record, without the XML overhead.
void PL::Bibliographic::index_library_card(OUTPUT_STREAM) { HTML_OPEN("p"); Index::anchor(OUT, I"LCARD"); HTML::begin_html_table(OUT, "*bg_images/indexcard.png", FALSE, 0, 3, 3, 0, 0); PL::Bibliographic::library_card_entry(OUT, "Story title", story_title_VAR, I"Untitled"); PL::Bibliographic::library_card_entry(OUT, "Story author", story_author_VAR, I"Anonymous"); PL::Bibliographic::library_card_entry(OUT, "Story headline", story_headline_VAR, I"An Interactive Fiction"); PL::Bibliographic::library_card_entry(OUT, "Story genre", story_genre_VAR, I"Fiction"); if (episode_number >= 0) { TEMPORARY_TEXT(episode_text) WRITE_TO(episode_text, "%d of %w", episode_number, series_name); PL::Bibliographic::library_card_entry(OUT, "Episode", NULL, episode_text); DISCARD_TEXT(episode_text) } PL::Bibliographic::library_card_entry(OUT, "Release number", story_release_number_VAR, I"1"); PL::Bibliographic::library_card_entry(OUT, "Story creation year", story_creation_year_VAR, I"(This year)"); TEMPORARY_TEXT(lang) inform_language *L = Projects::get_language_of_play(Task::project()); if (L == NULL) WRITE_TO(lang, "English"); else WRITE_TO(lang, "%X", L->as_copy->edition->work); PL::Bibliographic::library_card_entry(OUT, "Language of play", NULL, lang); DISCARD_TEXT(lang) PL::Bibliographic::library_card_entry(OUT, "IFID number", NULL, PL::Bibliographic::IFID::read_uuid()); PL::Bibliographic::library_card_entry(OUT, "Story description", story_description_VAR, I"None"); HTML::end_html_table(OUT); HTML_CLOSE("p"); }
void PL::Bibliographic::library_card_entry(OUTPUT_STREAM, char *field, nonlocal_variable *nlv, text_stream *t) { text_stream *col = I"303030"; if (nlv == story_title_VAR) col = I"803030"; HTML::first_html_column_nowrap(OUT, 0, NULL); HTML::begin_colour(OUT, col); HTML_OPEN_WITH("span", "class=\"typewritten\""); WRITE("%s", field); HTML_CLOSE("span"); HTML::end_colour(OUT); HTML::next_html_column(OUT, 0); HTML::begin_colour(OUT, col); HTML_OPEN_WITH("span", "class=\"typewritten\""); HTML_OPEN("b"); PL::Bibliographic::index_bibliographic_variable(OUT, nlv, t); HTML_CLOSE("b"); HTML_CLOSE("span"); HTML::end_colour(OUT); HTML::end_html_row(OUT); }
§13. The Index also likes to print the name and authorship at the top of the Contents listing, so:
void PL::Bibliographic::contents_heading(OUTPUT_STREAM) { if ((story_title_VAR == NULL) || (story_author_VAR == NULL)) WRITE("Contents"); else { PL::Bibliographic::index_bibliographic_variable(OUT, story_title_VAR, I"Untitled"); WRITE(" by "); PL::Bibliographic::index_bibliographic_variable(OUT, story_author_VAR, I"Anonymous"); } }
§14. And both of those features use:
void PL::Bibliographic::index_bibliographic_variable(OUTPUT_STREAM, nonlocal_variable *nlv, text_stream *t) { BEGIN_COMPILATION_MODE; COMPILATION_MODE_ENTER(COMPILE_TEXT_TO_XML_CMODE); if ((nlv) && (NonlocalVariables::has_initial_value_set(nlv))) { wording W = NonlocalVariables::treat_as_plain_text_word(nlv); PL::Bibliographic::compile_bibliographic_text(OUT, Lexer::word_text(Wordings::first_wn(W))); } else { WRITE("%S", t); } END_COMPILATION_MODE; }
§15. Bibliographic text. "Bibliographic text" is text used in bibliographic data about the work of IF compiled: for instance, in the iFiction record, or in the Library Card section of the HTML index. Note that the exact output format depends on global variables, which allow the bibliographic text writing code to configure Inform for its current purposes. On non-empty strings this routine therefore splits into one of three independent methods.
void PL::Bibliographic::compile_bibliographic_text(OUTPUT_STREAM, wchar_t *p) { if (p == NULL) return; if (TEST_COMPILATION_MODE(COMPILE_TEXT_TO_XML_CMODE)) Compile bibliographic text as XML respecting Treaty of Babel rules15.1; if (TEST_COMPILATION_MODE(TRUNCATE_TEXT_CMODE)) Compile bibliographic text as a truncated filename15.4; if (TEST_COMPILATION_MODE(COMPILE_TEXT_TO_I6_CMODE)) Compile bibliographic text as an I6 string15.3 Compile bibliographic text as HTML15.2; }
§15.1. This looks like a standard routine for converting ISO Latin-1 to UTF-8 with XML escapes, but there are a few conventions on whitespace, too, in order to comply with a strict reading of the Treaty of Babel. (This is intended for fields in iFiction records.)
Compile bibliographic text as XML respecting Treaty of Babel rules15.1 =
int i = 0, i2 = Wide::len(p)-1, snl, wsc; if ((p[0] == '"') && (p[i2] == '"')) { i++; i2--; } omit surrounding double-quotes while (Characters::is_babel_whitespace(p[i])) i++; omit leading whitespace while ((i2>=0) && (Characters::is_babel_whitespace(p[i2]))) i2--; omit trailing whitespace for (snl = FALSE, wsc = 0; i<=i2; i++) { switch(p[i]) { case ' ': case '\x0a': case '\x0d': case '\t': snl = FALSE; wsc++; int k = i; while ((p[k] == ' ') || (p[k] == '\x0a') || (p[k] == '\x0d') || (p[k] == '\t')) k++; if ((wsc == 1) && (p[k] != NEWLINE_IN_STRING)) WRITE(" "); break; case NEWLINE_IN_STRING: if (snl) break; WRITE("<br/>"); snl = TRUE; wsc = 1; break; case '[': if ((p[i+1] == '\'') && (p[i+2] == ']')) { i += 2; WRITE("'"); break; } int n = CompiledText::expand_unisub(OUT, p, i); if (n >= 0) { i = n; break; } and otherwise fall through to the default case default: snl = FALSE; wsc = 0; switch(p[i]) { case '&': WRITE("&"); break; case '<': WRITE("<"); break; case '>': WRITE(">"); break; default: PUT(p[i]); break; } break; } } return;
- This code is used in §15.
§15.2. In the HTML version, we want to respect the forcing of newlines, and also the ['] escape to obtain a literal single quotation mark.
Compile bibliographic text as HTML15.2 =
int i, whitespace_count=0; if (p[0] == '"') p++; for (i=0; p[i]; i++) { if ((p[i] == '"') && (p[i+1] == 0)) break; switch(p[i]) { case ' ': case '\x0a': case '\x0d': case '\t': whitespace_count++; if (whitespace_count == 1) PUT(' '); break; case NEWLINE_IN_STRING: while (p[i+1] == NEWLINE_IN_STRING) i++; PUT('<'); PUT('p'); PUT('>'); whitespace_count = 1; break; case '[': if ((p[i+1] == '\'') && (p[i+2] == ']')) { i += 2; PUT('\''); break; } int n = CompiledText::expand_unisub(OUT, p, i); if (n >= 0) { i = n; break; } and otherwise fall through to the default case default: whitespace_count = 0; PUT(p[i]); break; } } return;
- This code is used in §15.
§15.3. In the Inform 6 string version, we suppress the forcing of newlines, but otherwise it's much the same.
Compile bibliographic text as an I6 string15.3 =
int i, whitespace_count=0; if (p[0] == '"') p++; for (i=0; p[i]; i++) { if ((p[i] == '"') && (p[i+1] == 0)) break; switch(p[i]) { case ' ': case '\x0a': case '\x0d': case '\t': case NEWLINE_IN_STRING: whitespace_count++; if (whitespace_count == 1) PUT(' '); break; case '[': if ((p[i+1] == '\'') && (p[i+2] == ']')) { i += 2; PUT('\''); break; } and otherwise fall through to the default case default: whitespace_count = 0; PUT(p[i]); break; } } return;
- This code is used in §15.
§15.4. This code is used to work out a good filename for something given a name inside Inform. For instance, if a project is called
"St. Bartholemew's Fair: \'Etude for a Push-Me/Pull-You Machine"
then what would be a good filename for its released story file?
In the filename version we must forcibly truncate the text to ensure that it does not exceed a certain length, and must also make it filename-safe, omitting characters used as folder separators on various platforms and (for good measure) removing accents from accented letters, so that we can arrive at a sequence of ASCII characters. Each run of whitespace is also converted to a single space. If this would result in an empty text or only a single space, we return the text "story" instead.
Our example (if not truncated) then emerges as:
St- Bartholemew's Fair- Etude for a Push-Me-Pull-You Machine
Note that we do not write any filename extension (e.g., .z5) here.
We change possible filename separators or extension indicators to hyphens, and remove accents from each possible ISO Latin-1 accented letter. This does still mean that the OE and AE digraphs will simply be omitted, while the German eszet will be barbarously shortened to a single "s", but life is just too short to care overmuch about this.
Compile bibliographic text as a truncated filename15.4 =
int i, pos = STREAM_EXTENT(OUT), whitespace_count=0, black_chars_written = 0; int N = 100; #ifdef IF_MODULE N = BIBLIOGRAPHIC_TEXT_TRUNCATION; #endif if (p[0] == '"') p++; for (i=0; p[i]; i++) { if (STREAM_EXTENT(OUT) - pos >= N) break; if ((p[i] == '"') && (p[i+1] == 0)) break; switch(p[i]) { case ' ': case '\x0a': case '\x0d': case '\t': case NEWLINE_IN_STRING: whitespace_count++; if (whitespace_count == 1) PUT(' '); break; case '?': case '*': if ((p[i+1]) && (p[i+1] != '\"')) PUT('-'); break; default: { int charcode = p[i]; charcode = Characters::make_filename_safe(charcode); whitespace_count = 0; if (charcode < 128) { PUT(charcode); black_chars_written++; } break; } } } if (black_chars_written == 0) WRITE("story"); return;
- This code is used in §15.