+/* If TOKEN has the type of a scan error (a subset of those identified by
+ is_scan_type()), returns an appropriate error message. Otherwise, returns
+ NULL. */
+char *
+scan_token_to_error (const struct token *token)
+{
+ switch (token->type)
+ {
+ case SCAN_BAD_HEX_LENGTH:
+ return xasprintf (_("String of hex digits has %d characters, which "
+ "is not a multiple of 2."), (int) token->number);
+
+ case SCAN_BAD_HEX_DIGIT:
+ case SCAN_BAD_UNICODE_DIGIT:
+ return xasprintf (_("`%c' is not a valid hex digit."),
+ (int) token->number);
+
+ case SCAN_BAD_UNICODE_LENGTH:
+ return xasprintf (_("Unicode string contains %d bytes, which is "
+ "not in the valid range of 1 to 8 bytes."),
+ (int) token->number);
+
+ case SCAN_BAD_UNICODE_CODE_POINT:
+ return xasprintf (_("U+%04X is not a valid Unicode code point."),
+ (int) token->number);
+
+ case SCAN_EXPECTED_QUOTE:
+ return xasprintf (_("Unterminated string constant."));
+
+ case SCAN_EXPECTED_EXPONENT:
+ return xasprintf (_("Missing exponent following `%s'."),
+ token->string.string);
+
+ case SCAN_UNEXPECTED_CHAR:
+ char c_name[16];
+ return xasprintf (_("Bad character %s in input."),
+ uc_name (token->number, c_name));
+ }
+
+ return NULL;
+}
+