Written by Volkmar Frinken (@vfrinken). This is intended as a
lightweight (i.e. minimal dependencies) code generator that can be
ported to multiple platforms, especially those with memory constraints.
It shouldn't be expected to be anywhere near as fast as the Scheme back
end, for lots of reasons. The main goal is portability.
Refactor the DIY equational reasoning library to be a bit more like
the generic pre-order reasoning library:
Change the `...` notation into a constructor for a new `Step` datatype.
This seems to help idris disambiguate between the two kinds of
reasoning when they're used in the same file (e.g., frex).
Co-authored-by: Ohad Kammar <ohad.kammar@ed.ac.uk>
Division Theorem. For every natural number `x` and positive natural
number `n`, there is a unique decomposition:
`x = q*n + r`
with `q`,`r` natural and `r` < `n`.
`q` is the quotient when dividing `x` by `n`
`r` is the remainder when dividing `x` by `n`.
This commit adds a proof for this fact, in case
we want to reason about modular arithmetic (for example, when dealing
with binary representations). A future, more systematic, development could
perhaps follow: @clayrat 's (idris1) port of Coq's binary arithmetics:
https://github.com/sbp/idris-bi/blob/master/src/Data/Bin/DivMod.idrhttps://github.com/sbp/idris-bi/blob/master/src/Data/Biz/DivMod.idrhttps://github.com/sbp/idris-bi/blob/master/src/Data/BizMod2/DivMod.idr
In the process, it bulks up the stdlib with:
+ a generic PreorderReasoning module for arbitrary preorders,
analogous for the equational reasoning module
+ some missing facts about Nat operations.
+ Refactor some Nat order properties using a 'reflect' function
Co-authored-by: Ohad Kammar <ohad.kammar@ed.ac.uk>
Co-authored-by: G. Allais <guillaume.allais@ens-lyon.org>
This mirrors the (>>) found in Haskell, which is the same as (>>=), except the
second computation (on the right hand side) takes no arguments, and the result
of the first computation is discarded. This is a trivial implementation written
in terms of (>>=).
The Network.Socket.Data code previously used hardcoded constants manually read
from auto-generated C source code, however these constants are specific to
Linux. The original code looked like this:
export
ToCode SocketFamily where
-- Don't know how to read a constant value from C code in idris2...
-- gotta to hardcode those for now
toCode AF_UNSPEC = 0 -- unsafePerformIO (cMacro "#AF_UNSPEC" Int)
toCode AF_UNIX = 1
toCode AF_INET = 2
toCode AF_INET6 = 10
The AF_INET6 constant is correct on my Debian 10 laptop:
molly on flywheel ~> grep -rE '^#define AF_INET6' /usr/include
/usr/include/x86_64-linux-gnu/bits/socket.h:#define AF_INET6 PF_INET6
molly on flywheel ~> grep -rE '^#define PF_INET6' /usr/include
/usr/include/x86_64-linux-gnu/bits/socket.h:#define PF_INET6 10 /* IP version 6. */
However, this is not the case on an OpenBSD machine:
spanner# grep -rE '^#define[[:space:]]+AF_INET6' /usr/include
/usr/include/sys/socket.h:#define AF_INET6 24 /* IPv6 */
This commit adds accessor functions to the C runtime support library for
retrieving the values of these macros as they appear in the system libc header
files, which can then be invoked using the normal C FFI machinery.
Things like (,) () aren't straightforward IVar's but are IAlternative's
which present options about how the term should resolve. [| |] was not
accounting for this.
