mosaic-art-rust

Use when writing Rust that branches on an owned enum modeling state — TileStatus (NotStarted/InProgress/Completed) in the grid visualizer, a filled-vs-empty grid cell, a cache hit vs miss, or a simulated-annealing accept/reject decision — to choose behavior or a value, or when adding a variant to such an enum. Also when reaching for an if-let chain, a let-else, matches!, or a `_` wildcard arm to consume an enum this crate owns.

Use when composing or chaining Result values across the mosaic pipeline — sequencing image-load, decode, resize, and Lab-conversion steps (src/tile_cache.rs, src/similarity.rs); tempted by unwrap()/expect() on a missing material file or a corrupt similarity-cache JSON; discarding a save/load Result with let _ = ...; or deciding whether a failure becomes a CLI exit code (src/main.rs) or a rendered ProcessingState::Error (src/gui/app_full.rs).

Use when writing or modifying a Rust function with conditional branches — writing a per-tile or per-material loop that filters candidates, nesting a bounds check inside a usage-limit check, threading a `let mut best_match` through branches to return at the end, or wrapping a whole grid-loop body in a condition.

Use when converting between numeric types in this photomosaic generator, converting string↔number, or about to write `as` — u8 pixel channel ↔ f32 [0,1] color math, f32→u8 narrowing with clamp, usize↔u32 grid/tile index math, pixel counts (width * height) widened to f64 for averaging, or Lab/ΔE float math.

Use when authoring or converting Rust types in this photomosaic generator — defining a struct, enum, or function signature for grid cells, tile-placement outcomes, Lab colors, usage counts, adjacency penalties, or optimization config; typing several correlated fields as Option<T>; or about to reach for String, serde_json::Value, HashMap<String, String>, an over-permissive Vec<u8>, an `as` cast, or unwrap()/expect() to avoid modeling a value.

Use when branching on a file's extension or another string-token family with a growing match!/if-chain — e.g. supported material-image extensions "png"|"jpg"|"jpeg"|"webp" — especially when the same token-family test is duplicated across call sites (src/main.rs vs src/gui/app_full.rs) and has already drifted out of sync, or when adding several new format tokens to an existing check.

Use when naming or renaming a Rust function, method, struct, enum, trait, or module in this photomosaic crate — especially when a name is heading past three words (find_and_use_best_tile_with_position, process_tile_no_aspect_filter), contains and/or/with/if_missing (load_or_new), or describes several tile-selection or optimization steps at once.