From 14ff609b8efe96af660751031715081b1b63015c Mon Sep 17 00:00:00 2001
From: Luracasmus <77991691+Luracasmus@users.noreply.github.com>
Date: Sat, 22 Nov 2025 19:48:16 +0100
Subject: [PATCH] Apply `clippy::option_if_let_else`

---
 src/filters.rs | 33 +++++++++++++--------------------
 src/png/mod.rs |  9 ++++-----
 2 files changed, 17 insertions(+), 25 deletions(-)

diff --git a/src/filters.rs b/src/filters.rs
index a7922596..4826f762 100644
--- a/src/filters.rs
+++ b/src/filters.rs
@@ -127,22 +127,18 @@ impl RowFilter {
             }
             Self::Average => {
                 for (i, byte) in data.iter().enumerate() {
-                    buf.push(match i.checked_sub(bpp) {
-                        Some(x) => byte.wrapping_sub(
-                            ((u16::from(data[x]) + u16::from(prev_line[i])) >> 1) as u8,
-                        ),
-                        None => byte.wrapping_sub(prev_line[i] >> 1),
-                    });
+                    buf.push(byte.wrapping_sub(i.checked_sub(bpp).map_or_else(
+                        || prev_line[i] >> 1,
+                        |x| ((u16::from(data[x]) + u16::from(prev_line[i])) >> 1) as u8,
+                    )));
                 }
             }
             Self::Paeth => {
                 for (i, byte) in data.iter().enumerate() {
-                    buf.push(match i.checked_sub(bpp) {
-                        Some(x) => {
-                            byte.wrapping_sub(paeth_predictor(data[x], prev_line[i], prev_line[x]))
-                        }
-                        None => byte.wrapping_sub(prev_line[i]),
-                    });
+                    buf.push(byte.wrapping_sub(i.checked_sub(bpp).map_or_else(
+                        || prev_line[i],
+                        |x| paeth_predictor(data[x], prev_line[i], prev_line[x]),
+                    )));
                 }
             }
         }
@@ -241,10 +237,7 @@ impl RowFilter {
             Self::Sub => {
                 for (i, &cur) in data.iter().enumerate() {
                     let prev_byte = i.checked_sub(bpp).and_then(|x| buf.get(x).copied());
-                    buf.push(match prev_byte {
-                        Some(b) => cur.wrapping_add(b),
-                        None => cur,
-                    });
+                    buf.push(prev_byte.map_or(cur, |b| cur.wrapping_add(b)));
                 }
             }
             Self::Up => {
@@ -257,10 +250,10 @@ impl RowFilter {
             Self::Average => {
                 for (i, (&cur, &last)) in data.iter().zip(prev_line).enumerate() {
                     let prev_byte = i.checked_sub(bpp).and_then(|x| buf.get(x).copied());
-                    buf.push(match prev_byte {
-                        Some(b) => cur.wrapping_add(((u16::from(b) + u16::from(last)) >> 1) as u8),
-                        None => cur.wrapping_add(last >> 1),
-                    });
+                    buf.push(cur.wrapping_add(prev_byte.map_or_else(
+                        || last >> 1,
+                        |b| ((u16::from(b) + u16::from(last)) >> 1) as u8,
+                    )));
                 }
             }
             Self::Paeth => {
diff --git a/src/png/mod.rs b/src/png/mod.rs
index 81552edf..3b0da7c4 100644
--- a/src/png/mod.rs
+++ b/src/png/mod.rs
@@ -310,11 +310,10 @@ impl PngImage {
         match &self.ihdr.color_type {
             ColorType::Indexed { palette } => {
                 let plte = 12 + palette.len() * 3;
-                if let Some(trns) = palette.iter().rposition(|p| p.a != 255) {
-                    plte + 12 + trns + 1
-                } else {
-                    plte
-                }
+                palette
+                    .iter()
+                    .rposition(|p| p.a != 255)
+                    .map_or(plte, |trns| plte + 12 + trns + 1)
             }
             ColorType::Grayscale { transparent_shade } if transparent_shade.is_some() => 12 + 2,
             ColorType::RGB { transparent_color } if transparent_color.is_some() => 12 + 6,