cut down generator interface with rngs to minimum

src/board/sudoku.rs

@@ -215,26 +215,6 @@ impl Sudoku {
         Sudoku::generate_with_symmetry_and_rng_from(sudoku, symmetry, &mut rand::thread_rng())
     }
 
-    /// Generate a random, uniquely solvable sudoku with 180° rotational symmetry.
-    /// All random numbers are drawn from the given random number generator `rng`.
-    ///
-    /// The puzzles are minimal in that no cell can be removed without losing uniquess of the solution
-    /// whilst also upholding the symmetry.
-    /// Most puzzles generated by this are easy.
-    pub fn generate_with_rng<R: Rng + ?Sized>(rng: &mut R) -> Self {
-        Sudoku::generate_with_symmetry_and_rng_from(Sudoku::generate_solved_with_rng(rng), Symmetry::HalfRotation, rng)
-    }
-
-    /// Generate a random, uniquely solvable sudoku with the desired symmetry.
-    /// All random numbers are drawn from the given random number generator `rng`.
-    ///
-    /// The puzzles are minimal in that no cell can be removed without losing uniquess of the solution
-    /// whilst also upholding the symmetry.
-    /// Most puzzles generated by this are easy.
-    pub fn generate_with_symmetry_and_rng<R: Rng + ?Sized>(symmetry: Symmetry, rng: &mut R) -> Self {
-        Sudoku::generate_with_symmetry_and_rng_from(Sudoku::generate_solved_with_rng(rng), symmetry, rng)
-    }
-
     /// Generate a random, uniqely solvable sudoku
     /// that has the same solution as the given `sudoku` by removing the contents of some of its cells
     /// whilst upholding the `symmetry`. If the input sudoku is partially filled without the desired
@@ -244,7 +224,11 @@ impl Sudoku {
     /// Most puzzles generated by this from solved sudokus are easy.
     ///
     /// If the source `sudoku` is invalid or has multiple solutions, it will be returned as is.
-    pub fn generate_with_symmetry_and_rng_from<R: Rng + ?Sized>(mut sudoku: Sudoku, symmetry: Symmetry, rng: &mut R) -> Self {
+    pub fn generate_with_symmetry_and_rng_from<R: Rng + ?Sized>(
+        mut sudoku: Sudoku,
+        symmetry: Symmetry,
+        rng: &mut R,
+    ) -> Self {
         // this function is following
         // the approach outlined here: https://stackoverflow.com/a/7280517
         //