DEFINITION MODULE RealConversions ;
EXPORT QUALIFIED SetNoOfExponentDigits,
RealToString, StringToReal,
LongRealToString, StringToLongReal ;
(*
SetNoOfExponentDigits - sets the number of exponent digits to be
used during future calls of LongRealToString
and RealToString providing that the width
is sufficient.
If this value is set to 0 (the default) then
the number digits used is the minimum necessary.
*)
SetNoOfExponentDigits
PROCEDURE SetNoOfExponentDigits (places: CARDINAL) ;
(*
RealToString - converts a real, r, into a right justified string, str.
The number of digits to the right of the decimal point
is given in, digits. The value, width, represents the
maximum number of characters to be used in the string,
str.
If digits is negative then exponent notation is used
whereas if digits is positive then fixed point notation
is used.
If, r, is less than 0.0 then a '-' preceeds the value,
str. However, if, r, is >= 0.0 a '+' is not added.
If the conversion of, r, to a string requires more
than, width, characters then the string, str, is set
to a nul string and, ok is assigned FALSE.
For fixed point notation the minimum width required is
ABS(width)+8
For exponent notation the minimum width required is
ABS(digits)+2+log10(magnitude).
if r is a NaN then the string 'nan' is returned formatted and
ok will be FALSE.
*)
RealToString
PROCEDURE RealToString (r: REAL; digits, width: INTEGER;
VAR str: ARRAY OF CHAR; VAR ok: BOOLEAN) ;
(*
LongRealToString - converts a real, r, into a right justified string, str.
The number of digits to the right of the decimal point
is given in, digits. The value, width, represents the
maximum number of characters to be used in the string,
str.
If digits is negative then exponent notation is used
whereas if digits is positive then fixed point notation
is used.
If, r, is less than 0.0 then a '-' preceeds the value,
str. However, if, r, is >= 0.0 a '+' is not added.
If the conversion of, r, to a string requires more
than, width, characters then the string, str, is set
to a nul string and, ok is assigned FALSE.
For fixed point notation the minimum width required is
ABS(width)+8
For exponent notation the minimum width required is
ABS(digits)+2+log10(magnitude).
Examples:
RealToString(100.0, 10, 10, a, ok) -> '100.000000'
RealToString(100.0, -5, 12, a, ok) -> ' 1.00000E+2'
RealToString(123.456789, 10, 10, a, ok) -> '123.456789'
RealToString(123.456789, -5, 13, a, ok) -> ' 1.23456E+2'
RealToString(123.456789, -2, 15, a, ok) -> ' 1.23E+2'
if r is a NaN then the string 'nan' is returned formatted and
ok will be FALSE.
*)
LongRealToString
PROCEDURE LongRealToString (r: LONGREAL; digits, width: INTEGER;
VAR str: ARRAY OF CHAR; VAR ok: BOOLEAN) ;
(*
StringToReal - converts, str, into a REAL, r. The parameter, ok, is
set to TRUE if the conversion was successful.
*)
StringToReal
PROCEDURE StringToReal (str: ARRAY OF CHAR; VAR r: REAL; VAR ok: BOOLEAN) ;
(*
StringToLongReal - converts, str, into a LONGREAL, r. The parameter, ok, is
set to TRUE if the conversion was successful.
*)
StringToLongReal
PROCEDURE StringToLongReal (str: ARRAY OF CHAR; VAR r: LONGREAL; VAR ok: BOOLEAN) ;
END RealConversions.