example: iterative majority

[pazz]

This is a parametric example where in nfa-n one can control at most $2^n$ tokens.

This exposes a few bugs: first, shephert simply dies on nfa-3.dot.

> shepherd -f dot nfa-3.dot 
memory allocation of 234930447648 bytes failed

How very unRusty!
@Numero7 do have a look!

The second issue is that according to the logs running the prism iterator, these nfas are not complete. But they are!

[pazz]

(The second bug has now been fixed in #94)

[pazz]

Regarding the memory allocation issue, the following may help to debug.

I ran this command in gdb (prefix the command with gdb --args, type r to run, then type bt to print the back trace. HEre is what it gives.

 gdb --args ./target/debug/shepherd -f dot examples/iterated-majority/nfa-3.dot 
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Reading symbols from ./target/debug/shepherd...
warning: Missing auto-load script at offset 0 in section .debug_gdb_scripts
of file /home/patrick/projects/shepherd/target/debug/shepherd.
Use `info auto-load python-scripts [REGEXP]' to list them.
(gdb) r
Starting program: /home/patrick/projects/shepherd/target/debug/shepherd -f dot examples/iterated-majority/nfa-3.dot
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff7c866c0 (LWP 24236)]
[New Thread 0x7ffff7a856c0 (LWP 24237)]
[New Thread 0x7ffff78846c0 (LWP 24238)]
[New Thread 0x7ffff76836c0 (LWP 24239)]
memory allocation of 234930447648 bytes failed

Thread 1 "shepherd" received signal SIGABRT, Aborted.
0x00007ffff7e3a95c in ?? () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) bt
#0  0x00007ffff7e3a95c in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007ffff7de5cc2 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007ffff7dce4ac in abort () from /lib/x86_64-linux-gnu/libc.so.6
#3  0x0000555555f1f31a in std::sys::pal::unix::abort_internal () at library/std/src/sys/pal/unix/mod.rs:374
#4  0x00005555556f641a in std::process::abort () at library/std/src/process.rs:2375
#5  0x0000555555f32421 in std::alloc::rust_oom (layout=...) at library/std/src/alloc.rs:376
#6  0x0000555555f32443 in std::alloc::_::__rg_oom (size=0, align=24233) at library/std/src/alloc.rs:371
#7  0x00005555556f6d50 in alloc::alloc::handle_alloc_error::rt_error (layout=...) at library/alloc/src/alloc.rs:403
#8  alloc::alloc::handle_alloc_error (layout=...) at library/alloc/src/alloc.rs:409
#9  0x00005555556f6d3d in alloc::raw_vec::handle_error (e=...) at library/alloc/src/raw_vec.rs:792
#10 0x0000555555ae1ed0 in alloc::raw_vec::RawVecInner<alloc::alloc::Global>::with_capacity_in<alloc::alloc::Global> (capacity=9788768652, alloc=..., elem_layout=...)
    at /usr/src/rustc-1.85.0/library/alloc/src/raw_vec.rs:428
#11 0x00005555557602fc in alloc::raw_vec::RawVec<shepherd::ideal::Ideal, alloc::alloc::Global>::with_capacity_in<shepherd::ideal::Ideal, alloc::alloc::Global> (capacity=9788768652)
    at /usr/src/rustc-1.85.0/library/alloc/src/raw_vec.rs:192
#12 alloc::vec::Vec<shepherd::ideal::Ideal, alloc::alloc::Global>::with_capacity_in<shepherd::ideal::Ideal, alloc::alloc::Global> (capacity=9788768652)
    at /usr/src/rustc-1.85.0/library/alloc/src/vec/mod.rs:803
#13 alloc::vec::Vec<shepherd::ideal::Ideal, alloc::alloc::Global>::with_capacity<shepherd::ideal::Ideal> (capacity=9788768652) at /usr/src/rustc-1.85.0/library/alloc/src/vec/mod.rs:483
#14 alloc::vec::spec_from_iter_nested::{impl#0}::from_iter<shepherd::ideal::Ideal, core::iter::adapters::map::Map<itertools::adaptors::multi_product::MultiProduct<alloc::vec::into_iter::IntoIter<shepherd::coef::Coef, alloc::alloc::Global>>, fn(alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>) -> shepherd::ideal::Ideal>> (iterator=...)
    at /usr/src/rustc-1.85.0/library/alloc/src/vec/spec_from_iter_nested.rs:31
#15 0x0000555555771ffe in alloc::vec::spec_from_iter::{impl#0}::from_iter<shepherd::ideal::Ideal, core::iter::adapters::map::Map<itertools::adaptors::multi_product::MultiProduct<alloc::vec::into_iter::IntoIter<shepherd::coef::Coef, alloc::alloc::Global>>, fn(alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>) -> shepherd::ideal::Ideal>> (
    iterator=<error reading variable: Cannot access memory at address 0x5ea9>) at /usr/src/rustc-1.85.0/library/alloc/src/vec/spec_from_iter.rs:34
#16 0x0000555555770c21 in alloc::vec::{impl#15}::from_iter<shepherd::ideal::Ideal, core::iter::adapters::map::Map<itertools::adaptors::multi_product::MultiProduct<alloc::vec::into_iter::IntoIter<shepherd::coef::Coef, alloc::alloc::Global>>, fn(alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>) -> shepherd::ideal::Ideal>> (iter=...)
    at /usr/src/rustc-1.85.0/library/alloc/src/vec/mod.rs:3427
#17 0x0000555555811465 in core::iter::traits::iterator::Iterator::collect<core::iter::adapters::map::Map<itertools::adaptors::multi_product::MultiProduct<alloc::vec::into_iter::IntoIter<shepherd::coef::Coef, alloc::alloc::Global>>, fn(alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>) -> shepherd::ideal::Ideal>, alloc::vec::Vec<shepherd::ideal::Ideal, alloc::alloc::Global>> (self=<error reading variable: Cannot access memory at address 0x5ea9>) at /usr/src/rustc-1.85.0/library/core/src/iter/traits/iterator.rs:1971
#18 0x00005555557b25a3 in shepherd::downset::POSSIBLE_COEFS_CACHE::{closure#0}::{closure#0} (possible_coefs=0x7fffffffc670) at src/downset.rs:43
#19 0x000055555579b68f in core::ops::function::FnOnce::call_once<shepherd::downset::POSSIBLE_COEFS_CACHE::{closure#0}::{closure_env#0}, (&alloc::vec::Vec<alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>, alloc::alloc::Global>)> () at /usr/src/rustc-1.85.0/library/core/src/ops/function.rs:250
#20 0x0000555555799d3f in core::ops::function::Fn::call<fn(&alloc::vec::Vec<alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>, alloc::alloc::Global>) -> alloc::vec::Vec<shepherd::ideal::Ideal, alloc::alloc::Global>, (&alloc::vec::Vec<alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>, alloc::alloc::Global>)> ()
    at /usr/src/rustc-1.85.0/library/core/src/ops/function.rs:79
#21 0x00005555557e7764 in shepherd::memoizer::Memoizer<alloc::vec::Vec<alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>, alloc::alloc::Global>, alloc::vec::Vec<shepherd::ideal::Ideal, alloc::alloc::Global>, fn(&alloc::vec::Vec<alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>, alloc::alloc::Global>) -> alloc::vec::Vec<shepherd::ideal::Ideal, alloc::alloc::Global>>::get<alloc::vec::Vec<alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>, alloc::alloc::Global>, alloc::vec::Vec<shepherd::ideal::Ideal, alloc::alloc::Global>, fn(&alloc::vec::Vec<alloc::vec::Vec<shepherd::coef::Coef, alloc::alloc::Global>, alloc::alloc::Global>) -> alloc::vec::Vec<shepherd::ideal::Ideal, alloc::alloc::Global>> (
    self=0x555556371088 <shepherd::downset::POSSIBLE_COEFS_CACHE+24>, key=...) at src/memoizer.rs:31
#22 0x00005555557952c3 in shepherd::downset::DownSet::safe_pre_image (self=0x7fffffffcda0, edges=0x555556373878, maximal_finite_coordinate=11) at src/downset.rs:304
#23 0x000055555578904f in shepherd::strategy::Strategy::restrict_to (self=0x7fffffffcf58, safe=..., edges_per_letter=0x7fffffffd3c0, maximal_finite_value=11) at src/strategy.rs:43
#24 0x00005555557568f1 in shepherd::solver::update_strategy (dim=11, strategy=0x7fffffffcf58, final_states=..., edges=0x7fffffffd3c0, maximal_finite_value=11) at src/solver.rs:140
#25 0x0000555555755844 in shepherd::solver::compute_maximal_winning_strategy (dim=11, final_states=..., edges=..., letters=...) at src/solver.rs:62
#26 0x00005555557553c4 in shepherd::solver::solve (nfa=0x7fffffffd690, output=0x7fffffffd669) at src/solver.rs:31
#27 0x00005555556f7a97 in shepherd::main () at src/main.rs:27
(gdb) ```

[Numero7]

@pazz lot of memory is needed onnfa-3.dot , I will investigate