§1. Suppose we have an identifier name, say BlkValueCreate, which we think refers to some symbol in an Inter tree. How do we find it, coming up with the right inter_symbol?

The answer must depend on context, so the question really has to be "with the conventions given by this identifier_finder, what inter_symbol does this name correspond to?".

define MAX_IDENTIFIER_PRIORITIES 3

typedef struct identifier_finder {
    int no_priorities;
    struct inter_symbols_table *priorities[MAX_IDENTIFIER_PRIORITIES];
} identifier_finder;

• The structure identifier_finder is private to this section.

§2. The most basic set of conventions only allows us to see names visible everywhere:

identifier_finder IdentifierFinders::common_names_only(void) {
    identifier_finder finder;
    finder.no_priorities = 0;
    return finder;
}

§3. But we can add to that by providing up to three symbols tables to search in preference order (first match wins):

void IdentifierFinders::next_priority?Usage of IdentifierFinders::next_priority:
Emitting Inter Schemas - §2.1.3(identifier_finder *finder,
    inter_symbols_table *where) {
    if (finder->no_priorities >= MAX_IDENTIFIER_PRIORITIES)
        internal_error("too many identifier finder priorities");
    finder->priorities[finder->no_priorities++] = where;
}

§4. And here goes.

inter_symbol *IdentifierFinders::find?Usage of IdentifierFinders::find:
§5
Emitting Inter Schemas - §2.1.3, §3.1.10.2, §3.1.11.1(inter_tree *I, text_stream *name,
    identifier_finder finder) {
    if (Str::get_at(name, 0) == 0x00A7)
        Interpret this as an absolute URL4.1
    else
        Interpret this as an identifier4.2;
    LOG("Defeated on %S\n", name);
    internal_error("unable to find identifier");
    return NULL;
}

§4.1. If the name begins with this magic character, we interpret it as an absolute URL within the tree — the conventions are then unimportant: either the symbol exists where we said it is, or nothing is found. And in that case we will halt with an internal error: so this must be done speculatively.

Interpret this as an absolute URL4.1 =

    TEMPORARY_TEXT(SR)
    Str::copy(SR, name);
    Str::delete_first_character(SR);
    Str::delete_last_character(SR);
    inter_symbol *S = InterSymbolsTable::URL_to_symbol(I, SR);
    DISCARD_TEXT(SR)
    if (S) return S;

• This code is used in §4.

§4.2. Here, though, if all attempts to find the identifier fail, we in effect force it to exist by creating a plug with this name, and then returning that. So the above internal error cannot occur.

Interpret this as an identifier4.2 =

    for (int i = 0; i < finder.no_priorities; i++) {
        inter_symbol *S = InterSymbolsTable::symbol_from_name(finder.priorities[i], name);
        if (S) return S;
    }
    inter_symbol *S = LargeScale::find_architectural_symbol(I, name,
        Produce::kind_to_symbol(NULL));
    if (S) return S;
    S = InterSymbolsTable::symbol_from_name(LargeScale::connectors_scope(I), name);
    if (S) return S;
    S = InterSymbolsTable::symbol_from_name(LargeScale::main_scope(I), name);
    if (S) return S;
    S = InterNames::to_symbol(HierarchyLocations::find_by_name(I, name));
    if (S) return S;

• This code is used in §4.

§5. A small variation. Note that a token can be marked explicitly with an iname to which it corresponds; if it has been, then this overrides the finding process, because the symbol which that iname incarnates as must be the right one.

inter_symbol *IdentifierFinders::find_token?Usage of IdentifierFinders::find_token:
Emitting Inter Schemas - §3.1.2.1, §3.1.7.2(inter_tree *I, inter_schema_token *t,
    identifier_finder finder) {
    if (t->as_quoted) return InterNames::to_symbol(t->as_quoted);
    #ifdef CORE_MODULE
    local_variable *lvar = LocalVariables::by_identifier(t->material);
    if (lvar) return LocalVariables::declare(lvar);
    #endif
    return IdentifierFinders::find(I, t->material, finder);
}