(* Library module defined by the International Standard
   Information technology - programming languages
   BS ISO/IEC 10514-1:1996E Part 1: Modula-2, Base Language.

   Copyright ISO/IEC (International Organization for Standardization
   and International Electrotechnical Commission) 1996-2021.

   It may be freely copied for the purpose of implementation (see page
   707 of the Information technology - Programming languages Part 1:
   Modula-2, Base Language.  BS ISO/IEC 10514-1:1996).  *)

DEFINITION MODULE LowReal;

  (* Access to underlying properties of the type REAL *)

CONST
  radix      = __ATTRIBUTE__ __BUILTIN__ (( <REAL, radix> )) ;      (* ZType *)
  places     = __ATTRIBUTE__ __BUILTIN__ (( <REAL, places> )) ;     (* ZType *)
  expoMin    = __ATTRIBUTE__ __BUILTIN__ (( <REAL, expoMin> )) ;    (* ZType *)
  expoMax    = __ATTRIBUTE__ __BUILTIN__ (( <REAL, expoMax> )) ;    (* ZType *)
  large      = __ATTRIBUTE__ __BUILTIN__ (( <REAL, large> )) ;      (* RType *)
  small      = __ATTRIBUTE__ __BUILTIN__ (( <REAL, small> )) ;      (* RType *)
  IEC559     = __ATTRIBUTE__ __BUILTIN__ (( <REAL, IEC559> )) ;     (* BOOLEAN *)
  LIA1       = __ATTRIBUTE__ __BUILTIN__ (( <REAL, LIA1> )) ;       (* BOOLEAN *)
  ISO        = __ATTRIBUTE__ __BUILTIN__ (( <REAL, ISO> )) ;        (* BOOLEAN *)
  IEEE       = __ATTRIBUTE__ __BUILTIN__ (( <REAL, IEEE> )) ;       (* BOOLEAN *)
  rounds     = __ATTRIBUTE__ __BUILTIN__ (( <REAL, rounds> )) ;     (* BOOLEAN *)
  gUnderflow = __ATTRIBUTE__ __BUILTIN__ (( <REAL, gUnderflow> )) ; (* BOOLEAN *)
  exception  = __ATTRIBUTE__ __BUILTIN__ (( <REAL, exception> )) ;  (* BOOLEAN *)
  extend     = __ATTRIBUTE__ __BUILTIN__ (( <REAL, extend> )) ;     (* BOOLEAN *)
  nModes     = __ATTRIBUTE__ __BUILTIN__ (( <REAL, nModes> )) ;     (* ZType *)

TYPE
  Modes = PACKEDSET OF [0..nModes-1];

PROCEDURE exponent (x: REAL): INTEGER;
  (* Returns the exponent value of x *)

PROCEDURE fraction (x: REAL): REAL;
  (* Returns the significand (or significant part) of x *)

PROCEDURE sign (x: REAL): REAL;
  (* Returns the signum of x *)

PROCEDURE succ (x: REAL): REAL;
  (* Returns the next value of the type REAL greater than x *)

PROCEDURE ulp (x: REAL): REAL;
  (* Returns the value of a unit in the last place of x *)

PROCEDURE pred (x: REAL): REAL;
  (* Returns the previous value of the type REAL less than x *)

PROCEDURE intpart (x: REAL): REAL;
  (* Returns the integer part of x *)

PROCEDURE fractpart (x: REAL): REAL;
  (* Returns the fractional part of x *)

PROCEDURE scale (x: REAL; n: INTEGER): REAL;
  (* Returns the value of x * radix ** n *)

PROCEDURE trunc (x: REAL; n: INTEGER): REAL;
  (* Returns the value of the first n places of x *)

PROCEDURE round (x: REAL; n: INTEGER): REAL;
  (* Returns the value of x rounded to the first n places *)

PROCEDURE synthesize (expart: INTEGER; frapart: REAL): REAL;
  (* Returns a value of the type REAL constructed from the given expart and frapart *)

PROCEDURE setMode (m: Modes);
  (* Sets status flags appropriate to the underlying implementation of the type REAL *)

PROCEDURE currentMode (): Modes;
  (* Returns the current status flags in the form set by setMode *)

PROCEDURE IsLowException (): BOOLEAN;
  (* Returns TRUE if the current coroutine is in the exceptional execution state
     because of the raising of an exception in a routine from this module; otherwise
     returns FALSE.
  *)

END LowReal.

