presidentscroob

    site:foo.com -site:docs.foo.com ((lemons "crab apples") or ((oranges beans) (cherries plums)))

    search = "( search ")"
           | "-" search
           | search ("and")? search
           | search "or" search
           | constraint
           | term

    term = quoted_term
         | simple_term

    quoted_term = '"'([^"\\]|'\\"')+'"'
                | "'"([^'\\]|"\\'")+"'"

    simple_term = [^'" ]+

    constraint = file_type_constraint
               | url_constraint
               | site_constraint
               | temporal_constraint

    file_type_constraint = "filetype:" (common_type|"*"?"."?[a-z0-9]+)
                         | "mimetype:" regex

    common_type = "video"|"photo"|"audio"|"email"|"web"|"document"|"text"

    url_constraint = "inurl:" regex
 
    site_constraint = "site:" regex

    time_constraint = "before:" date 
                    | "after:" date
                    | "within:" time

    /* "and," "or," and : prefixes should be case-insensitive and localizable */
    /* date, time and regex are "exercises for the reader" ;) */

    int
    some_func(void) {
      int result = ERR;

      HANDLE foo = alloc_foo();
      if (!foo) goto err0;

      HANDLE bar = alloc_bar();
      if (!bar) goto err1;

      if (do_something_else() < 0) goto err2;

      result = OK;
    err2:
      release_bar(bar);
    err1
      release_foo(foo);
    err0:
      return result;
    }