Preloaded Library

• type: basic types (int, char, string, float, bool, unit, exn, 'a array, 'a list) and the types 'a option (see page ??) and ('a, 'b, 'c) format (see page ??).
  
  
• exceptions: A number of exceptions are raisable by the execution library. Some of the more common ones are the following:
  • Failure of string that is raised by the function failwith applied to a string.
  • Invalid_argument of string that indicates that an argument cannot be handled by the function having raised the exception. The function invalid_arg applied to a string starts this exception.
  • Sys_error of string, for the input/output, typically in attempting to open a nonexistent file for reading.
  • End_of_file for detecting the end of a file.
  • Division_by_zero for zero divide errors between integers.
  As well as internal exceptions like:
  • Out_of_memory and Stack_overflow for going beyond the memory of the heap or the stack. It should be noted that a program cannot recover from the Out_of_memory exception. In effect, when it is raised it is too late to allocate new memory space to continue functioning.
    Handling the Stack_Overflow exception differs depending on whether the program was compiled in byte code or native code. In the latter case, it is not possible to recover.
  
  
• functions: there are roughly 140, half of which correspond to the C functions of the execution library. There you may find mathematical and comparison operators, functions on integer and floating-point numbers, functions on character strings, on references and input-output. It should be noted that a certain number of these declarations are in fact synonyms for declarations defined in other modules. They are nevertheless declared here for historical and implementation reasons.