"Chapter 4.6 Debugging" has some unclear explanations

[MRGRAVITY817]

Where in the docs did you come across this?

1. In "Add logging to our game of life" section, there's no instruction which to put this code.

   
   #![allow(unused_variables)]
   fn main() {
   extern crate web_sys;

// A macro to provide println!(..)-style syntax for console.log logging. macro_rules! log { ( $( $t:tt ) ) => { web_sys::console::log_1(&format!( $( $t ) ).into()); } } }

2. And also this seems like a snippet from git history, which is uneasy to read.

diff --git a/src/lib.rs b/src/lib.rs index f757641..a30e107 100755 --- a/src/lib.rs +++ b/src/lib.rs @@ -123,6 +122,14 @@ impl Universe { let cell = self.cells[idx]; let live_neighbors = self.live_neighbor_count(row, col);

• log!(

• "cell[{}, {}] is initially {:?} and has {} live neighbors",

• row,

• col,

• cell,

• live_neighbors

• );

•          let next_cell = match (cell, live_neighbors) {
               // Rule 1: Any live cell with fewer than two live neighbours
               // dies, as if caused by underpopulation.

  @@ -140,6 +147,8 @@ impl Universe { (otherwise, _) => otherwise, };

• log!(" it becomes {:?}", next_cell);

•          next[idx] = next_cell;
       }
   }

**How could we improve it?**