{"id":294,"date":"2015-02-22T11:16:26","date_gmt":"2015-02-22T11:16:26","guid":{"rendered":"https:\/\/projects.lsv.ens-paris-saclay.fr\/orchidsdoc\/?page_id=294"},"modified":"2017-12-08T10:48:03","modified_gmt":"2017-12-08T10:48:03","slug":"operators","status":"publish","type":"page","link":"https:\/\/projects.lsv.ens-paris-saclay.fr\/orchidsdoc\/?page_id=294","title":{"rendered":"Operators"},"content":{"rendered":"

Each operator is given with its signature, consisting of a list of allowed typings, tried in order.
\nA typing is of the form type1<\/sub><\/em>, …, typen<\/sub><\/em> \u2192 return-type<\/em>.<\/p>\n

Arithmetic<\/h3>\n
    \n
  • addition, concatenation<\/strong>:\n
      \n
    • + : int, int \u2192 int<\/code><\/li>\n
    • + : uint, uint \u2192 uint<\/code><\/li>\n
    • + : float, float \u2192 float<\/code><\/li>\n
    • + : ctime, ctime \u2192 ctime<\/code><\/li>\n
    • + : ctime, int \u2192 ctime<\/code><\/li>\n
    • + : ctime, timeval \u2192 timeval<\/code><\/li>\n
    • + : timeval, int \u2192 timeval<\/code><\/li>\n
    • + : timeval, ctime \u2192 timeval<\/code><\/li>\n
    • + : timeval, timeval \u2192 timeval<\/code>
      \nNote: all of the above forms implement truncated<\/em> addition, not addition modulo 2N<\/sup><\/em> for any N<\/em>. This is done so that addition is monotonic in its arguments.<\/li>\n
    • + : str, str \u2192 str<\/code> (string concatenation)<\/li>\n
    • + : db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>], db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>] \u2192 db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>]<\/code><\/li>\n
    • + : db[*], db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>] \u2192 db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>]<\/code><\/li>\n
    • + : db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>], db[*] \u2192 db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>]<\/code><\/li>\n
    • + : db[*], db[*] \u2192 db[*]<\/code>
      \n(database union)
      \nNote: the two input database types must be identical, or at least one of them is the special type db[*]<\/code> that only the empty database can have..<\/li>\n<\/ul>\n<\/li>\n
    • subtraction<\/strong>:\n
        \n
      • - : int, int \u2192 int<\/code><\/li>\n
      • - : uint, uint \u2192 uint<\/code><\/li>\n
      • - : float, float \u2192 float<\/code><\/li>\n
      • - : ctime, ctime \u2192 ctime<\/code><\/li>\n
      • - : ctime, int \u2192 ctime<\/code><\/li>\n
      • - : timeval, int \u2192 timeval<\/code><\/li>\n
      • - : timeval, ctime \u2192 timeval<\/code><\/li>\n
      • - : timeval, timeval \u2192 timeval<\/code>
        \nNote: all of the above forms implement truncated<\/em> subtraction, not subtraction modulo 2N<\/sup><\/em> for any N<\/em>. This is done so that subtraction is monotonic in its first argument, and antitonic in its second argument.<\/li>\n
      • - : db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>], db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>] \u2192 db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>]<\/code><\/li>\n
      • - : db[*], db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>] \u2192 db[*]<\/code><\/li>\n
      • - : db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>], db[*] \u2192 db[<\/code>type<\/em>1<\/sub>, …, typen<\/sub><\/em>]<\/code><\/li>\n
      • - : db[*], db[*] \u2192 db[*]<\/code>
        \n(database difference)
        \nNote: the two input database types must be identical, or at least one of them is the special type db[*]<\/code> that only the empty database can have.
        \nComputes first database without all the tuples of the second database.<\/li>\n<\/ul>\n<\/li>\n
      • opposite<\/strong>:\n
          \n
        • - : int \u2192 int<\/code>
          \nNote: the above form implements truncated<\/em> opposite, not opposite modulo 2N<\/sup><\/em> for any N<\/em>. This is done so that opposite is monotonic in its argument. The only surprising case is taking the opposite of the least possible int (-2N-1<\/sup><\/em>, where N<\/em> is the bit size), which yields the largest possible int (2N-1<\/sup><\/em>-1) instead of the modulo value, -2N<\/sup><\/em>.<\/li>\n
        • - : uint \u2192 int<\/code>
          \nAgain, this is truncated opposite.<\/li>\n
        • - : float \u2192 float<\/code><\/li>\n<\/ul>\n<\/li>\n
        • same sign conversion<\/strong>:\n