Features

Kind Parameters

Real kinds

Parameter	Precision	Range	Size
R16P	33 digits	$[{10}^{-4931},{10}^{+4931}-1]$	128 bit
R8P	15 digits	$[{10}^{-307},{10}^{+307}-1]$	64 bit
R4P	6 digits	$[{10}^{-37},{10}^{+37}-1]$	32 bit

Integer kinds

Parameter	Range	Size
I8P	$[-2^{63},+2^{63}-1]$	64 bit
I4P	$[-2^{31},+2^{31}-1]$	32 bit
I2P	$[-2^{15},+2^{15}-1]$	16 bit
I1P	$[-2^7,+2^7-1]$	8 bit

Format Strings

Each kind has a matching format string for print / write statements:

Kind	Format string	Example output
R16P	FR16P = '(E42.33E4)'	-0.100000000000000000000000000000000E+0001
R8P	FR8P = '(E23.15E3)'	-0.100000000000000E+001
R4P	FR4P = '(E13.6E2)'	-0.100000E+01
I8P	FI8P = '(I20)'	-1
I4P	FI4P = '(I11)'	-1
I2P	FI2P = '(I6)'	-1
I1P	FI1P = '(I4)'	-1

use penf
call penf_init

real(R8P)    :: x = -1.0_R8P
integer(I4P) :: n = 42_I4P

print FR8P, x !  -0.100000000000000E+001
print FI4P, n !          42

Modules

PENF is composed of four modules that build upon each other:

• penf_global_parameters_variables — all portable kind parameters, format strings, and character kinds
• penf_b_size — bit_size() and byte_size() extended to reals and characters
• penf_stringify — comprehensive number↔string conversions: str(), strz(), cton(), bstr(), bcton()
• penf_allocatable_memory — allocatable memory utilities: allocate_variable(), assign_allocatable(), memory tracking
• penf — main module, re-exports everything and provides check_endian(), digit(), penf_init(), penf_print()

Any feature request is welcome — open an issue on GitHub.