time-to-botec

commit f6391a3d79faf59e28419d5cf768bfdb8157583d
parent dbc83899c2dfdaea44b5a7f100ac3568c2820bc9
Author: NunoSempere <nuno.semperelh@protonmail.com>
Date:   Sat,  6 Apr 2024 00:24:48 -0400

tweak mutable references (not working tho)

Diffstat:
M
rust/src/main.rs
 | 
18
++++++++++++++----
A
rust/tmp.txt
 | 
40
++++++++++++++++++++++++++++++++++++++++

2 files changed, 54 insertions(+), 4 deletions(-)
diff --git a/rust/src/main.rs b/rust/src/main.rs
@@ -1,16 +1,26 @@
 use rand_core::SeedableRng;
-use rand_distr::{Distribution, Normal};
 use rand_pcg::Pcg64Mcg;
+use rand_distr::{Normal, Distribution};
 
 // use rand::thread_rng;
 // use rand::prelude::*
 
+fn model(rng: &mut Pcg64Mcg) -> f64 {
+    let x = 1.0;
+    let normal = Normal::new(2.0, 3.0).unwrap();
+    let v = normal.sample(&mut rng);
+    v * x
+}
+
 fn main() {
     println!("Hello, world!");
 
     let mut rng = Pcg64Mcg::seed_from_u64(1);
     // mean 2, standard deviation 3
-    let normal = Normal::new(2.0, 3.0).unwrap();
-    let v = normal.sample(&mut rng);
-    println!("{} is from a N(2, 9) distribution", v)
+    let v = model(&mut rng);
+    println!("{} is from a N(2, 9) distribution", v);
+    let z = model(&mut rng);
+    println!("{} is from a N(2, 9) distribution", z);
 }
+
+
diff --git a/rust/tmp.txt b/rust/tmp.txt
@@ -0,0 +1,40 @@
+
+
+   Compiling squiggle_rust v0.1.0 (/home/nuno/Documents/core/software/fresh/time-to-botec/rust)
+warning: variable does not need to be mutable
+  --> src/main.rs:18:9
+   |
+18 |     let mut rng = Pcg64Mcg::seed_from_u64(1);
+   |         ----^^^
+   |         |
+   |         help: remove this `mut`
+   |
+   = note: `#[warn(unused_mut)]` on by default
+
+error[E0382]: use of moved value: `rng`
+  --> src/main.rs:22:19
+   |
+18 |     let mut rng = Pcg64Mcg::seed_from_u64(1);
+   |         ------- move occurs because `rng` has type `Mcg128Xsl64`, which does not implement the `Copy` trait
+19 |     // mean 2, standard deviation 3
+20 |     let v = model(rng);
+   |                   --- value moved here
+21 |     println!("{} is from a N(2, 9) distribution", v);
+22 |     let z = model(rng);
+   |                   ^^^ value used here after move
+   |
+note: consider changing this parameter type in function `model` to borrow instead if owning the value isn't necessary
+  --> src/main.rs:8:19
+   |
+8  | fn model(mut rng: Pcg64Mcg) -> f64 {
+   |    -----          ^^^^^^^^ this parameter takes ownership of the value
+   |    |
+   |    in this function
+help: consider cloning the value if the performance cost is acceptable
+   |
+20 |     let v = model(rng.clone());
+   |                      ++++++++
+
+For more information about this error, try `rustc --explain E0382`.
+warning: `squiggle_rust` (bin "squiggle_rust") generated 1 warning
+error: could not compile `squiggle_rust` (bin "squiggle_rust") due to 1 previous error; 1 warning emitted