+is_identifier (uniqstr s)
+{
+ static char const alphanum[26 + 26 + 1 + 10] =
+ "abcdefghijklmnopqrstuvwxyz"
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "_"
+ "0123456789";
+ if (!s || ! memchr (alphanum, *s, sizeof alphanum - 10))
+ return false;
+ for (++s; *s; ++s)
+ if (! memchr (alphanum, *s, sizeof alphanum))
+ return false;
+ return true;
+}
+
+
+/*-----------------------------------------------.
+| Get the identifier associated to this symbol. |
+`-----------------------------------------------*/
+uniqstr
+symbol_id_get (symbol const *sym)
+{
+ aver (sym->user_token_number != USER_NUMBER_HAS_STRING_ALIAS);
+ if (sym->alias)
+ sym = sym->alias;
+ return is_identifier (sym->tag) ? sym->tag : 0;
+}
+
+
+/*------------------------------------------------------------------.
+| Complain that S's WHAT is redeclared at SECOND, and was first set |
+| at FIRST. |
+`------------------------------------------------------------------*/
+
+static void
+symbol_redeclaration (symbol *s, const char *what, location first,
+ location second)
+{
+ unsigned i = 0;
+ complain_indent (&second, complaint, &i,
+ _("%s redeclaration for %s"), what, s->tag);
+ i += SUB_INDENT;
+ complain_indent (&first, complaint, &i,
+ _("previous declaration"));
+}
+
+static void
+semantic_type_redeclaration (semantic_type *s, const char *what, location first,
+ location second)
+{
+ unsigned i = 0;
+ complain_indent (&second, complaint, &i,
+ _("%s redeclaration for <%s>"), what, s->tag);
+ i += SUB_INDENT;
+ complain_indent (&first, complaint, &i,
+ _("previous declaration"));
+}
+
+
+
+/*-----------------------------------------------------------------.
+| Set the TYPE_NAME associated with SYM. Does nothing if passed 0 |
+| as TYPE_NAME. |
+`-----------------------------------------------------------------*/
+
+void
+symbol_type_set (symbol *sym, uniqstr type_name, location loc)
+{
+ if (type_name)
+ {
+ if (sym->type_name)
+ symbol_redeclaration (sym, "%type", sym->type_location, loc);
+ uniqstr_assert (type_name);
+ sym->type_name = type_name;
+ sym->type_location = loc;
+ }
+}
+
+/*--------------------------------------------------------.
+| Set the DESTRUCTOR or PRINTER associated with the SYM. |
+`--------------------------------------------------------*/
+
+void
+symbol_code_props_set (symbol *sym, code_props_type kind,
+ code_props const *code)
+{
+ if (sym->props[kind].code)
+ symbol_redeclaration (sym, code_props_type_string (kind),
+ sym->props[kind].location,
+ code->location);
+ sym->props[kind] = *code;
+}
+
+/*-----------------------------------------------------.
+| Set the DESTRUCTOR or PRINTER associated with TYPE. |
+`-----------------------------------------------------*/
+
+void
+semantic_type_code_props_set (semantic_type *type,
+ code_props_type kind,
+ code_props const *code)
+{
+ if (type->props[kind].code)
+ semantic_type_redeclaration (type, code_props_type_string (kind),
+ type->props[kind].location,
+ code->location);
+ type->props[kind] = *code;
+}
+
+/*---------------------------------------------------.
+| Get the computed %destructor or %printer for SYM. |
+`---------------------------------------------------*/
+
+code_props *
+symbol_code_props_get (symbol *sym, code_props_type kind)