Standard Feature Identifiers

An implementation may provide any or all of the feature identifiers listed below for use by cond-expand and features, but must not provide a feature identifier if it does not provide the corresponding feature.

r7rsAll R7RS​ ​Scheme implementations have this feature.

exact-closedThe algebraic operations +, -, *, and expt where the second argument is a non-negative integer produce exact values given exact inputs.

exact-complexExact complex numbers are provided.

ieee-floatInexact numbers are IEEE 754 binary floating point values.

full-unicodeAll Unicode characters present in Unicode version 6.0 are supported as Scheme characters.

ratios/ with exact arguments produces an exact result when the divisor is nonzero.

posixThis implementation is running on a POSIX system.

windowsThis implementation is running on Windows.

unix, darwin, gnu-linux, bsd, freebsd, solaris, ...Operating system flags (perhaps more than one).

i386, x86-64, ppc, sparc, jvm, clr, llvm, ...CPU architecture flags.

ilp32, lp64, ilp64, ...C memory model flags.

big-endian, little-endianByte order flags.

<name>The name of this implementation.

<name-version>The name and version of this implementation.