5.1 Environment enquiries

An environment enquiry is a constant or a procedure, whose elaboration yields a value that may be useful to the programmer, that reflects some characteristic of the particular implementation. The values of these enquiries are also determined by the architecture and operating system targeted by the compiler.

Constant: int int lengths

1 plus the number of extra lenghts of integers which are meaningful.

Constant: int int shorths

1 plus the number of extra shorths of integers which are meaningful.

Constant: l int L max int

The largest integral value.

Constant: int real lengths

1 plus the number of extra lenghts of real numbers which are meaningful.

Constant: int real shorths

1 plus the number of extra shorths of real numbers which are meaningful.

Constant: l real L max real

The largest real value.

Constant: l real L small real

The smallest real value such that both 1 + small real > 1 and 1 - small real < 1.

Constant: int bits lengths

1 plus the number of extra widths of bits which are meaningful.

Constant: int bits shorths

1 plus the number of extra shorths of bits which are meaningful.

Constant: int bits width
Constant: int long bits width
Constant: int long long bits width

The number of bits in a bits value.

Constant: int bytes lengths

1 plus the number of extra widths of bytes which are meaningful.

Constant: int bytes shorths

1 plus the number of extra shorths of bytes which are meaningful.

Constant: int bytes width
Constant: int long bytes width
Constant: int long long bytes width

The number of chars in a bytes value.

Constant: int max abs char

The largest value which abs of a char can yield.

Constant: char null character

Some character.

Constant: char flip
Constant: char flop

Characters used to represent true and false boolean values in textual transput.

Constant: char error char

Character used to represent the digit of a value resulting from a conversion error in textual transput.

Constant: char blank

The space character.

Constant: l real L pi

The number pi.