Some cleanliness cleanups

This commit is contained in:
Chris Hodapp 2020-03-31 16:57:58 -04:00
parent 45ab4ed9e0
commit e26b528464
4 changed files with 29 additions and 324 deletions

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@ -3,13 +3,14 @@
## Highest priority:
- If my `closure_try2` branch seems to be working: start converting
other things and cleaning everything up. (`twist` is still ugly.)
other things and cleaning everything up. (`twist` is still ugly.
Look at all my TODOs in it.)
- See `automata_scratch/examples.py` and implement some of the tougher
examples.
- `spiral_nested_2` & `spiral_nested_3` (how to compose
efficiently?)
- `twisty_torus`
- `ram_horn_branch` - how do I pass depth in order to do this right?
- `ram_horn_branch` - Can I pass depth via a closure?
## Important but less critical:

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@ -2,11 +2,10 @@ use std::rc::Rc;
use nalgebra::*;
//pub mod examples;
use crate::openmesh::{OpenMesh, Tag, Mat4, Vertex, vertex, transform};
use crate::openmesh::{OpenMesh, Mat4, vertex, transform};
use crate::rule::{Rule, RuleFn, RuleEval, Child};
use crate::prim;
use crate::util;
use crate::scratch;
fn cube_thing() -> Rule {
@ -369,12 +368,14 @@ fn twist(f: f32, subdiv: usize) -> Rule {
// TODO: Clean this code up. It was a very naive conversion from
// the non-closure version.
let xf = geometry::Rotation3::from_axis_angle(&Vector3::x_axis(), -0.7).to_homogeneous();
let seed = transform(&vec![
vertex(-0.5, 0.0, -0.5),
vertex( 0.5, 0.0, -0.5),
vertex( 0.5, 0.0, 0.5),
vertex(-0.5, 0.0, 0.5),
], &xf);
let seed = {
let s = vec![vertex(-0.5, 0.0, -0.5),
vertex( 0.5, 0.0, -0.5),
vertex( 0.5, 0.0, 0.5),
vertex(-0.5, 0.0, 0.5)];
util::subdivide_cycle(&transform(&s, &xf), subdiv)
};
let n = seed.len();
let dx0: f32 = 1.5;
let dy: f32 = 0.1/f;
let ang: f32 = 0.05/f;
@ -390,23 +391,24 @@ fn twist(f: f32, subdiv: usize) -> Rule {
let incr_outer = geometry::Translation3::new(-dx0*2.0, 0.0, 0.0).to_homogeneous() *
geometry::Rotation3::from_axis_angle(&y, ang/2.0).to_homogeneous() *
geometry::Translation3::new(dx0*2.0, dy, 0.0).to_homogeneous();
// TODO: Cleanliness fix - transforms?
let seed2 = seed.clone();
// TODO: Why do I need the above?
let recur = move |incr: Mat4| -> RuleFn {
let seed_orig = transform(&seed2, &incr);
let seed_sub = util::subdivide_cycle(&seed_orig, subdiv);
let n = seed_sub.len();
let seed_next = transform(&seed2, &incr);
// TODO: Cleanliness fix - utility function to make a zigzag mesh?
let geom = OpenMesh {
verts: seed_sub.clone(),
verts: seed_next.clone(),
faces: util::parallel_zigzag_faces(n),
};
let (vc, faces) = util::connect_convex(&seed_sub, true);
// TODO: Cleanliness fix - why not just make these return meshes?
let (vc, faces) = util::connect_convex(&seed_next, true);
let final_geom = OpenMesh {
verts: vec![vc],
faces: faces.clone(),
faces: faces,
};
let c = move |self_: Rc<Rule>| -> RuleEval {
@ -427,30 +429,30 @@ fn twist(f: f32, subdiv: usize) -> Rule {
};
Box::new(c)
};
// TODO: Can a macro do anything to clean up some of the
// repetition with HOFs & closures?
// TODO: so there's incr_inner & incr_outer that I wanted to
// parametrize over. why is it so ugly to do so?
let start = move |self_: Rc<Rule>| -> RuleEval {
let start = move |_| -> RuleEval {
let xform = |dx, i, ang0, div| -> Mat4 {
(geometry::Rotation3::from_axis_angle(&y, ang0 + (qtr / div * (i as f32))).to_homogeneous() *
geometry::Translation3::new(dx, 0.0, 0.0).to_homogeneous())
};
// TODO: Cleanliness fix - transforms?
let make_child = |i, incr, xform| -> (OpenMesh, Child) {
let seed_orig = transform(&seed, &incr);
let seed_sub = util::subdivide_cycle(&seed_orig, subdiv);
let n = seed_sub.len();
let make_child = |incr, xform| -> (OpenMesh, Child) {
let c = Child {
rule: Rc::new(Rule { eval: (recur.clone())(incr) }),
// TODO: Cleanliness fix - can macros clean up above?
xf: xform,
vmap: (0..(n+1)).collect(),
// N.B. n+1, not n. the +1 is for the centroid below
// N.B. n+1, not n. the +1 is for the centroid below.
};
let mut vs = transform(&seed_sub, &xform);
let mut vs = transform(&seed, &xform);
// and in the process, generate faces for these seeds:
let (centroid, f) = util::connect_convex(&vs, false);
vs.push(centroid);
@ -458,8 +460,8 @@ fn twist(f: f32, subdiv: usize) -> Rule {
};
// Generate 'count' children, shifted/rotated differently:
let children_inner = (0..count).map(|i| make_child(i, incr_inner, xform(dx0, i, 0.0, 1.0)));
let children_outer = (0..count).map(|i| make_child(i, incr_outer, xform(dx0*2.0, i, qtr/2.0, 2.0)));
let children_inner = (0..count).map(|i| make_child(incr_inner, xform(dx0, i, 0.0, 1.0)));
let children_outer = (0..count).map(|i| make_child(incr_outer, xform(dx0*2.0, i, qtr/2.0, 2.0)));
RuleEval::from_pairs(
children_inner.chain(children_outer), prim::empty_mesh())

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@ -1,4 +1,3 @@
pub mod scratch;
pub mod examples;
pub mod openmesh;
pub mod rule;

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@ -1,297 +0,0 @@
use std::rc::Rc;
/*
struct R<'a> {
b: &'a dyn Fn() -> R<'a>,
}
#[derive(Copy, Clone)]
struct Foo {}
impl<'a> Foo {
// These are valid, but not especially useful (if I am
// transferring ownership then I cannot have any branching):
fn fn1(self) -> R<'a> {
R { b: & move || self.fn1() }
}
fn fn2(self) -> R<'a> {
R { b: &|| self.fn2() }
}
}
*/
// Below (using box instead of a trait object) follows similar rules:
struct S<'a> {
b: Box<dyn Fn() -> S<'a>>,
}
#[derive(Copy, Clone)]
struct Foo2 {}
impl<'a> Foo2 {
fn fn1(self) -> S<'a> {
S { b: Box::new(move || self.fn1()) }
}
// Not valid (error[E0373]: closure may outlive the current
// function, but it borrows `self`, which is owned by the current
// function):
//fn fn2(self) -> S<'a> {
// S { b: Box::new(|| self.fn2()) }
//}
// Not valid:
//fn fn3(&self) -> S<'a> {
// S { b: Box::new(move || self.fn3()) }
//}
// Not valid:
//fn fn4(&self) -> S<'a> {
// S { b: Box::new(|| self.fn4()) }
//}
}
struct T<'a> {
b: Rc<dyn Fn() -> T<'a> + 'a>,
}
#[derive(Copy, Clone)]
struct Foo3 {}
impl<'a> Foo3 {
fn fn1(self) -> T<'a> {
T { b: Rc::new(move || self.fn1()) }
}
// Not valid (E0373):
//fn fn2(self) -> T<'a> {
// T { b: Rc::new(|| self.fn2()) }
//}
// Not valid:
//fn fn3(&self) -> T<'a> {
// T { b: Rc::new(move || self.fn3()) }
//}
// Not valid:
//fn fn4(&self) -> T<'a> {
// T { b: Rc::new(|| self.fn4()) }
//}
// But this is now valid because T can be cloned:
fn fn5(self) -> (T<'a>, T<'a>) {
let p = Rc::new(move || self.fn1());
let p2 = p.clone();
(T { b: p }, T { b: p2 })
}
}
// Further, this is now valid too (lifetimes removed):
struct U {
b: Rc<dyn Fn() -> U>,
}
#[derive(Copy, Clone)]
struct Foo4 {}
impl Foo4 {
fn fn1(self) -> U {
U { b: Rc::new(move || self.fn1()) }
}
fn fn5(self) -> (U, U) {
let p = Rc::new(move || self.fn1());
let p2 = p.clone();
(U { b: p }, U { b: p2 })
}
}
// I can get rid of Copy/Clone if I use FnOnce:
struct V {
b: Rc<dyn FnOnce() -> V>,
}
struct Foo5 {}
impl Foo5 {
fn fn1(self) -> V {
V { b: Rc::new(move || self.fn1()) }
}
fn fn2(self) -> (V, V) {
let p = Rc::new(move || self.fn1());
let p2 = p.clone();
(V { b: p }, V { b: p2 })
}
// and then either kind is fine:
fn fn3(self) -> V {
V { b: Rc::new(|| self.fn3()) }
}
fn fn4(self) -> (V, V) {
let p = Rc::new(|| self.fn3());
let p2 = p.clone();
(V { b: p }, V { b: p2 })
// but this confuses me a bit. doesn't this then let me call
// an FnOnce... more than once?
}
}
// This is valid and I can recurse:
struct W {
b: Box<dyn Fn() -> W>,
}
struct Foo6 {}
impl Foo6 {
fn fn1(s: &Rc<Self>) -> W {
let s2 = Rc::clone(&s);
W { b: Box::new(move || Self::fn1(&s2)) }
}
fn fn2(s: &Rc<Self>) -> (W, W) {
let s2 = Rc::clone(&s);
let w2 = W { b: Box::new(move || Self::fn1(&s2)) };
let s3 = Rc::clone(&s);
let w3 = W { b: Box::new(move || Self::fn1(&s3)) };
(w2, w3)
}
}
fn foo6() {
// Whatever (note that it doesn't automatically do Copy):
struct State {
v: u32,
}
// Purposely put state somewhere it goes out of scope:
let s = {
let s_orig = State {
v: 105,
};
Rc::new(s_orig)
};
/*
let fn1 = |f: &dyn Fn(&dyn Fn() -> W) -> (&dyn Fn() -> W)| -> (&dyn Fn() -> W) {
&(|| -> W {
let s2 = Rc::clone(&s);
W { b: Box::new(move || f(f)) }
})
};
let f2 = fn1(fn1);
*/
}
fn foo7(t: impl Clone) -> impl Clone {
t.clone()
}
fn foo7b<T: Clone>(t: T) -> T {
t.clone()
}
fn foo7c<T>(t: T) -> T where T: Clone {
t.clone()
}
// A simple implementation of the Y Combinator
// λf.(λx.xx)(λx.f(xx))
// <=> λf.(λx.f(xx))(λx.f(xx))
// CREDITS: A better version of the previous code that was posted here, with detailed explanation.
// See <y> and also <y_apply>.
// A function type that takes its own type as an input is an infinite recursive type.
// We introduce a trait that will allow us to have an input with the same type as self, and break the recursion.
// The input is going to be a trait object that implements the desired function in the interface.
// NOTE: We will be coercing a reference to a closure into this trait object.
trait Apply<T, R> {
fn apply(&self, f: &dyn Apply<T, R>, t: T) -> R;
}
// In Rust, closures fall into three kinds: FnOnce, FnMut and Fn.
// FnOnce assumed to be able to be called just once if it is not Clone. It is impossible to
// write recursive FnOnce that is not Clone.
// All FnMut are also FnOnce, although you can call them multiple times, they are not allow to
// have a reference to themselves. So it is also not possible to write recursive FnMut closures
// that is not Clone.
// All Fn are also FnMut, and all closures of Fn are also Clone. However, programmers can create
// Fn objects that are not Clone
// This will work for all Fn objects, not just closures
// And it is a little bit more efficient for Fn closures as it do not clone itself.
impl<T, R, F> Apply<T, R> for F where F:
Fn(&dyn Apply<T, R>, T) -> R
{
fn apply(&self, f: &dyn Apply<T, R>, t: T) -> R {
self(f, t)
// NOTE: Each letter is an individual symbol.
// (λx.(λy.xxy))(λx.(λy.f(λz.xxz)y))t
// => (λx.xx)(λx.f(xx))t
// => (Yf)t
}
}
// This works for all closures that is Clone, and those are Fn.
// impl<T, R, F> Apply<T, R> for F where F: FnOnce( &Apply<T, R>, T ) -> R + Clone {
// fn apply( &self, f: &Apply<T, R>, t: T ) -> R {
// (self.clone())( f, t )
// // If we were to pass in self as f, we get -
// // NOTE: Each letter is an individual symbol.
// // λf.λt.sft
// // => λs.λt.sst [s/f]
// // => λs.ss
// }
// }
// Before 1.26 we have some limitations and so we need some workarounds. But now impl Trait is stable and we can
// write the following:
fn y<T,R>(f:impl Fn(&dyn Fn(T) -> R, T) -> R) -> impl Fn(T) -> R {
move |t| (
|x: &dyn Apply<T,R>, y| x.apply(x, y)
) (
&|x: &dyn Apply<T,R>, y| f(
&|z| x.apply(x,z),
y
),
t
)
}
// fn y<T,R>(f:impl FnOnce(&Fn(T) -> R, T) -> R + Clone) -> impl FnOnce(T) -> R {
// |t| (|x: &Apply<T,R>,y| x.apply(x,y))
// (&move |x:&Apply<T,R>,y| f(&|z| x.apply(x,z), y), t)
// // NOTE: Each letter is an individual symbol.
// // (λx.(λy.xxy))(λx.(λy.f(λz.xxz)y))t
// // => (λx.xx)(λx.f(xx))t
// // => (Yf)t
// }
// Previous version removed as they are just hacks when impl Trait is not available.
fn fac(n: usize) -> usize {
let almost_fac = |f: &dyn Fn(usize) -> usize, x|
if x == 0 {
1
} else {
x * f(x - 1)
}
;
let fac = y( almost_fac );
fac(n)
}
fn fib( n: usize ) -> usize {
let almost_fib = |f: &dyn Fn(usize) -> usize, x|
if x < 2 {
1
} else {
f(x - 2) + f(x - 1)
};
let fib = y(almost_fib);
fib(n)
}
fn optimal_fib( n: usize ) -> usize {
let almost_fib = |f: &dyn Fn((usize,usize,usize)) -> usize, (i0,i1,x)|
match x {
0 => i0,
1 => i1,
x => f((i1,i0+i1, x-1))
}
;
let fib = |x| y(almost_fib)((1,1,x));
fib(n)
}
fn test_y() {
println!("{}", fac(10));
println!("{}", fib(10));
println!("{}", optimal_fib(10));
}