Measure width of characters

Cargo.toml

@@ -4,3 +4,8 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+anyhow = "1.0.57"
+crossterm = "0.23.2"
+unicode-blocks = "0.1.4"
+unicode-segmentation = "1.9.0"
+unicode-width = "0.1.9"

src/main.rs

@@ -0,0 +1,63 @@
+use std::collections::HashMap;
+use std::{io, slice};
+
+use crossterm::cursor::{self, MoveTo};
+use crossterm::execute;
+use crossterm::style::Print;
+use crossterm::terminal::{EnterAlternateScreen, LeaveAlternateScreen};
+use unicode_blocks::UnicodeBlock;
+use unicode_segmentation::UnicodeSegmentation;
+use unicode_width::UnicodeWidthStr;
+
+struct WidthDB(HashMap<String, u8>);
+
+impl WidthDB {
+    fn new() -> Self {
+        Self(HashMap::new())
+    }
+
+    fn measure(&mut self, s: &str) -> anyhow::Result<()> {
+        let mut stdout = io::stdout();
+        for grapheme in s.graphemes(true) {
+            execute!(stdout, EnterAlternateScreen, MoveTo(0, 0), Print(grapheme))?;
+            let width = cursor::position()?.0 as u8;
+            if width != grapheme.width() as u8 {
+                self.0.insert(grapheme.to_string(), width);
+            }
+            execute!(stdout, LeaveAlternateScreen)?;
+        }
+        Ok(())
+    }
+
+    fn measure_block(&mut self, block: UnicodeBlock) -> anyhow::Result<()> {
+        for c in block.start()..=block.end() {
+            let c = char::from_u32(c).unwrap();
+            let s = c.to_string();
+            self.measure(&s)?;
+        }
+        Ok(())
+    }
+}
+
+fn main() {
+    let mut widthdb = WidthDB::new();
+
+    // widthdb.measure_block(unicode_blocks::BASIC_LATIN);
+    // widthdb.measure_block(unicode_blocks::LATIN_1_SUPPLEMENT);
+    // widthdb.measure_block(unicode_blocks::LATIN_EXTENDED_A);
+    // widthdb.measure_block(unicode_blocks::LATIN_EXTENDED_ADDITIONAL);
+    // widthdb.measure_block(unicode_blocks::LATIN_EXTENDED_B);
+    // widthdb.measure_block(unicode_blocks::LATIN_EXTENDED_C);
+    // widthdb.measure_block(unicode_blocks::LATIN_EXTENDED_D);
+    // widthdb.measure_block(unicode_blocks::LATIN_EXTENDED_E);
+    // widthdb.measure_block(unicode_blocks::LATIN_EXTENDED_F);
+    // widthdb.measure_block(unicode_blocks::LATIN_EXTENDED_G);
+    // widthdb.measure_block(unicode_blocks::EMOTICONS);
+    widthdb.measure_block(unicode_blocks::BOX_DRAWING);
+
+    println!();
+    for (grapheme, width) in widthdb.0 {
+        let expected = grapheme.width();
+        println!("{grapheme} = {width} (expected: {expected})");
+    }
+}