To work out the verbs used and to diagram sentences in the source.
+ ++ +
§1. Traversing for primary verbs. The story so far: the supervisor module has arranged for the source +text to be read in by words and has made a rudimentary parse tree for +it using syntax. Certain "structural" sentences, such as headings, have +been taken care of, and turned into nodes with types like HEADING_NT. +
+ +But the assertions we want to read — such as "The Mona Lisa is in the Louvre", +or "The plural of major general is majors general" — are all simply +SENTENCE_NT nodes with no children. The following traverse begins Inform's +compilation process in earnest: for each such SENTENCE_NT node, it asks +the linguistics module to identify a primary verb, noun phrases and so +on, placing them in a subtree. +
+ ++int classification_traverse_done = FALSE; + +void Classifying::traverse(void) { + SyntaxTree::traverse(Task::syntax_tree(), Classifying::visit); + classification_traverse_done = TRUE; +} + +void Classifying::visit(parse_node *p) { + if (Node::get_type(p) == TRACE_NT) { + SyntaxTree::toggle_trace(Task::syntax_tree()); + Log::tracing_on(SyntaxTree::is_trace_set(Task::syntax_tree()), I"Diagramming"); + } + if (Node::get_type(p) == SENTENCE_NT) { + Classifying::sentence(p); + Sentences::Rearrangement::check_sentence_for_direction_creation(p); + } +} ++
§2. Certain extra sentences, called "inventions", are sometimes created after +that traverse takes place: those extra SENTENCE_NT nodes therefore won't +be caught. Extra sentences can happen in two ways: +
+ +- (a) When additional text is fed to the lexer and sentence-broken by the +syntax module, at which point syntax calls the function below +because we have given it as a callback. +
- (b) When explicit rearrangement of the tree causes new SENTENCE_NT nodes +to be created. Any code doing this should call the following function +explicitly. +
define NEW_NONSTRUCTURAL_SENTENCE_SYNTAX_CALLBACK Classifying::visit_extra_sentence ++
+void Classifying::visit_extra_sentence(parse_node *new) { + if (classification_traverse_done) Classifying::sentence(new); +} ++
§3. Textual sentences. "Textual" sentences are not really sentences at all, and are just double-quoted +text used in isolation — Inform sometimes recognises these as being implicit +property values, as for the description of a room just created. These sentences +are necessarily exempt from having a primary verb. +
+ ++int Classifying::sentence_is_textual(parse_node *p) { + if ((Wordings::length(Node::get_text(p)) == 1) && + (Vocabulary::test_flags( + Wordings::first_wn(Node::get_text(p)), TEXT_MC+TEXTWITHSUBS_MC))) + return TRUE; + return FALSE; +} ++
§4. Classifying a single sentence. Every SENTENCE_NT node, however it is constructed, therefore ends up here, +and we ask the linguistics module to "diagram" it. +
+ +See About Sentence Diagrams (in linguistics) for many examples. +
+ ++void Classifying::sentence(parse_node *p) { + if (Classifying::sentence_is_textual(p) == FALSE) { + wording W = Node::get_text(p); + if (<sentence-without-occurrences>(W)) { + parse_node *VP_PN = <<rp>>; + switch (Annotations::read_int(VP_PN, linguistic_error_here_ANNOT)) { + case TwoLikelihoods_LINERROR: Issue PM_TwoLikelihoods problem4.1; break; + } + SyntaxTree::graft(Task::syntax_tree(), VP_PN, p); + if (SyntaxTree::is_trace_set(Task::syntax_tree())) LOG("$T\n", p); + Check that this is allowed, if it occurs in the Options file4.2; + } else { + LOG("$T\n", p); + <no-primary-verb-diagnosis>(W); + } + } +} ++
§4.1. Issue PM_TwoLikelihoods problem4.1 = +
+ ++ StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_TwoLikelihoods), + "this sentence seems to have a likelihood qualification on both " + "sides of the verb", + "which is not allowed. 'The black door certainly is usually open' " + "might possibly be grammatical English in some idioms, but Inform " + "doesn't like a sentence in this shape because the 'certainly' " + "on one side of the verb and the 'usually' on the other are " + "rival indications of certainty."); ++
- This code is used in §4.
§4.2. Only special-meaning sentences are allowed in Options files, and not all +of those. +
+ +Check that this is allowed, if it occurs in the Options file4.2 = +
+ ++ if (Wordings::within(Node::get_text(p), options_file_wording)) { + special_meaning_holder *sm = Node::get_special_meaning(p->down); + if ((sm == NULL) || + (SpecialMeanings::call(sm, ALLOW_IN_OPTIONS_FILE_SMFT, NULL, NULL) == FALSE)) + StandardProblems::unlocated_problem(Task::syntax_tree(), + _p_(BelievedImpossible), not convenient to test automatically, anyway + "The options file placed in this installation of Inform's folder " + "is incorrect, making use of a sentence form which isn't allowed " + "in that situation. The options file is only allowed to contain " + "use options, Test ... with..., and Release along with... " + "instructions."); + } ++
- This code is used in §4.
§5. From the earliest beta-testing, the problem message for "I can't find a verb" +split into cases. Inform is quite sensitive to punctuation errors as between +comma, paragraph break and semicolon, and this is where that sensitivity begins +to bite. The grammar below is just a set of heuristics, really: once we enter +this, a problem message of some kind will certainly result. +
+ ++<no-primary-verb-diagnosis> ::= + ... <no-primary-verb-diagnosis-tail> | + before/every/after/when/instead/check/carry/report ... | ==> Issue PM_RuleWithoutColon problem5.1 + if ... | ==> Issue PM_IfOutsidePhrase problem5.2 + ... , ... | ==> Issue PM_NoSuchVerbComma problem5.3 + ... ==> Issue PM_NoSuchVerb problem5.4 + +<no-primary-verb-diagnosis-tail> ::= + <rc-marker> <certainty> <nonimperative-verb> ... | ==> { advance Wordings::delta(WR[1], W) } + <rc-marker> <nonimperative-verb> ... | ==> { advance Wordings::delta(WR[1], W) } + <past-tense-verb> ... | ==> Issue PM_NonPresentTense problem5.5 + <negated-verb> ... ==> Issue PM_NegatedVerb1 problem5.6 ++
- This is Preform grammar, not regular C code.
§5.1. Issue PM_RuleWithoutColon problem5.1 = +
+ ++ StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_RuleWithoutColon), + "I can't find a verb that I know how to deal with, so can't do anything " + "with this sentence. It looks as if it might be a rule definition", + "but if so then it is lacking the necessary colon (or comma). " + "The punctuation style for rules is 'Rule conditions: do this; " + "do that; do some more.' Perhaps you used a full stop instead " + "of the colon?"); ++
- This code is used in §5.
§5.2. Issue PM_IfOutsidePhrase problem5.2 = +
+ ++ StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_IfOutsidePhrase), + "I can't find a verb that I know how to deal with. This looks like an 'if' " + "phrase which has slipped its moorings", + "so I am ignoring it. ('If' phrases, like all other such " + "instructions, belong inside definitions of rules or phrases - " + "not as sentences which have no context. Maybe a full stop or a " + "skipped line was accidentally used instead of semicolon, so that you " + "inadvertently ended the last rule early?)"); ++
- This code is used in §5.
§5.3. Issue PM_NoSuchVerbComma problem5.3 = +
+ ++ Problems::quote_source(1, current_sentence); + StandardProblems::handmade_problem(Task::syntax_tree(), _p_(PM_NoSuchVerbComma)); + Problems::issue_problem_segment( + "In the sentence %1, I can't find a verb that I know how to deal with. " + "(I notice there's a comma here, which is sometimes used to abbreviate " + "rules which would normally be written with a colon - for instance, " + "'Before taking: say \"You draw breath.\"' can be abbreviated to 'Before " + "taking, say...' - but that's only allowed for Before, Instead and " + "After rules. I mention all this in case you meant this sentence " + "as a rule in some rulebook, but used a comma where there should " + "have been a colon ':'?)"); + Problems::issue_problem_end(); ++
- This code is used in §5.
§5.4. Issue PM_NoSuchVerb problem5.4 = +
+ ++ Problems::quote_source(1, current_sentence); + StandardProblems::handmade_problem(Task::syntax_tree(), _p_(PM_NoSuchVerb)); + Problems::issue_problem_segment( + "In the sentence %1, I can't find a verb that I know how to deal with."); + Problems::issue_problem_end(); ++
- This code is used in §5.
§5.5. Issue PM_NonPresentTense problem5.5 = +
+ ++ if (Annotations::read_int(current_sentence, verb_problem_issued_ANNOT) == FALSE) { + Annotations::write_int(current_sentence, verb_problem_issued_ANNOT, TRUE); + StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_NonPresentTense), + "assertions about the initial state of play must be given in the " + "present tense", + "so 'The cat is in the basket' is fine but not 'The cat has been in " + "the basket'. Time is presumed to start only when the game begins, so " + "there is no anterior state which we can speak of."); + } ++
- This code is used in §5.
§5.6. Issue PM_NegatedVerb1 problem5.6 = +
+ ++ if (Annotations::read_int(current_sentence, verb_problem_issued_ANNOT) == FALSE) { + Annotations::write_int(current_sentence, verb_problem_issued_ANNOT, TRUE); + StandardProblems::negative_sentence_problem(Task::syntax_tree(), _p_(PM_NegatedVerb1)); + } ++
- This code is used in §5.