+/*----------------------------------------.
+| Create a new semantic type, named TAG. |
+`----------------------------------------*/
+
+static semantic_type *
+semantic_type_new (uniqstr tag)
+{
+ semantic_type *res = xmalloc (sizeof *res);
+
+ uniqstr_assert (tag);
+ res->tag = tag;
+ code_props_none_init (&res->destructor);
+ code_props_none_init (&res->printer);
+
+ return res;
+}
+
+
+/*-----------------.
+| Print a symbol. |
+`-----------------*/
+
+#define SYMBOL_ATTR_PRINT(Attr) \
+ if (s->Attr) \
+ fprintf (f, " %s { %s }", #Attr, s->Attr)
+
+#define SYMBOL_CODE_PRINT(Attr) \
+ if (s->Attr.code) \
+ fprintf (f, " %s { %s }", #Attr, s->Attr.code)
+
+void
+symbol_print (symbol *s, FILE *f)
+{
+ if (s)
+ {
+ fprintf (f, "\"%s\"", s->tag);
+ SYMBOL_ATTR_PRINT (type_name);
+ SYMBOL_CODE_PRINT (destructor);
+ SYMBOL_CODE_PRINT (printer);
+ }
+ else
+ fprintf (f, "<NULL>");
+}
+
+#undef SYMBOL_ATTR_PRINT
+#undef SYMBOL_CODE_PRINT
+
+
+/*----------------------------------.
+| Whether S is a valid identifier. |
+`----------------------------------*/
+
+static bool
+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;
+}
+