Pike 8.1: Changes since Pike 8.0 (scratch area for future release notes)
New language features
o Unlimited character constant size.
There is no longer any limit to the size of character constants,
e.g. 'acdefghijk' creates the bignum 0x61636465666768696a6b.
o 'auto' type added.
This is much like a strict typed mixed. The actual type is deduced
Typical use is as the type for variables in foreach when looping over
complexly typed values, or as the type in macro-defined functions and
auto can be used as return type for a function, it will be the
logical or of all the types of the return statements in the
o typeof(X) can now be used as a type.
The main use case is in macros, but it might be useful for other
things as well (as an example in a typedef).
typedef typeof(Val.true)|typeof(Val.false) bool;
typeof, when used like this, behaves very much like the C++
o ** operator added. It's exponentiation and works with most
combination of numerical types (int,float,Gmp.mpq,Gmp.mpf,Gmp.mpz)
`** and ``** operator overloading functions added.
This introduces one incompatible change: Previously the "pow"
function called a "_pow" function in the first argument if it was an
object. It has now been changed to also use `** (or, rather, pow()
is now implemented using predef::`**()).
o Random rewrite
The random functions have been rewritten to ensure security by
default. random_string() and random() now get their data directly
from the operating system random generator, i.e. /dev/urandom on
most unixen. This is about half the speed compared with the
random_string function in Pike 8.0, but is now as secure as the
system random generator.
For consumers of random data that have additional requirements,
different random generators are exposed in the new module
Random. The module has the following generators:
This is not actually a generator, but an interface class that is
inherited into all the other generators. It contains code that can
turn the output from the random_string method into random numbers
with different limits without introducing bias. It also contains
code for all the different variants of random() on different
types. This is currently not possible to implement in Pike code,
as the typing is too complicated and it is not possible to access
private/protected _random methods in objects.
This generator maps directly on top of the system random
generator. This is the default generator used for random() and
This generator creates the same sequence of random numbers for a
given seed, with good pseudo random properties.
This generator accesses the hardware random generator, when
This generator takes entropy from the Random.System, but feeds
it into a cryptographic pseudo random number generator to be
able to output data fast. This is not the default random number
generator to avoid loading crypto code on every startup.
Comparing the different generators with each other gives the
following approximate speeds on a Linux system with hardware
Pike 8.0 random_string 0.45
Objects implementing the _random lfun now get two arguments, the
current random_string() and random() functions. This is convenient
for C-level functions that doesn't have to look up functions
themselves. Note that it is possible for a user to replace these
with non-conforming functions (returning values of the wrong type,
strings of the wrong length or shift size, and values outside the
given range) or even non-functions.
All code in Pike that uses random now uses the current random
functions (though in some cases fixed at object creation). This
allows for repeatable results if the random functions are replaced
with a deterministic random generator, such as
Random.Deterministic rnd = Random.Deterministic( seed );
add_constant( "random_string", rnd->random_string );
add_constant( "random", rnd->random );
o Gz.crc32 now only returns positive results.
o glob() has changed.
The main incompatibilities are that [ and \ are now special
characters in the pattern, and if you check the return value against
1 instead of checking if it's true, and use an array as the first
argument you will have to change your code.
This is in order to extend the glob function to cover what
'standard' glob functions do:
glob() now accepts quotes (\* to match a single *, as an example)
and handles ranges ([abc] for a, b or c, [a-z0-9] for a single
character between a and z or 0-9
You can also negate a range using ^ or ! ([^a-zA-Z] as an example).
When the first argument (the pattern) to glob is an array, glob now
returns which pattern in the array matched.
o hash() has changed to use siphash. The old hash function is
available under the name hash_7_8(). Note that this is not a
cryptographic hash function.
Deprecated symbols and modules
o Sql.mysql_result and Sql.mysqls_result have been deprecated.
Use Sql.Result instead.
Removed features and modules
o Compatibility for Pike versions before 7.8 is no longer available.
o GTK1 library is deprecated, so glue code is removed.
o Concurrent.Future and Concurrent.Promise
These are used to simplify handling of asynchronous results.
This module collect non-cryptographic checksums. Support for crc32,
adler32 and Castagnoli CRC (CRC32C).
o Gmp.mpf is now implemented using gmpf if the library is available.
C-level API changes
o The contract for functions is now changed so that a function is no
longer required to clean the stack. The topmost value of the stack
will be regarded as the return value and the rest of the items on
the stack, compared to before the function arguments were pushed,
will be popped and discarded. Efuns still have to clean their stack
o Removed add_function, pike_add_function, pike_add_function2,
simple_add_variable, map_variable and MAP_VARIABLE. This removes the
remaining few API:s where text types were used. Use ADD_FUNCTION and
o Removed the functions my_rand and my_srand. Use the random functions
on the stack for _random lfuns, the push_random_string or look up
the random function from get_builtin_constants(). For deterministic
pseudo random, create a private Random.Deterministic object.
Building and installing
o GMP 4.1 or later is now required.
o C99 assumed
The configure tests will not check for functions defined in C99
anymore and C99 compiler support is assumed.