Parse and format Quantities (#63)

The last thing remaining needing support from the v0 version of the
language was the Quantity type, whereby numeric values can have
uncertainty, magnitude, and units, for example

    5.9722 ± 0.0006 × 10²⁴ kg

We add support in the parser for detecting quantity numericals, and
appropriate code for presenting them nicely when formatting output.

It also turned out that we weren't accounting for the width of Unicode
characters when printing error messages. That is fixed, along with
ensuring that the caret points to the best location relative to where
the problem is.

Author: istathar

Cargo.toml

@@ -17,3 +17,8 @@ tracing = "0.1.40"
 tracing-subscriber = { version = "0.3.18", features = [ "env-filter" ] }
 
 [build-dependencies]
+
+[profile.release]
+debug = "limited"
+strip = true
+lto = true

LICENSE

@@ -1,4 +1,4 @@
-Copyright © 2002-2024 Athae Eredh Siniath and Others
+Copyright © 2002-2025 Athae Eredh Siniath and Others
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the "Software"),

src/error/display.rs

@@ -25,7 +25,7 @@ impl<'i> TechniqueError<'i> {
             .unwrap_or("?");
 
         let line = i + 1;
-        let column = j;
+        let column = j + 1;
 
         let width = line
             .to_string()
@@ -38,7 +38,7 @@ impl<'i> TechniqueError<'i> {
 
 {:width$} {}
 {:width$} {} {}
-{:width$} {} {:>j$}
+{:width$} {} {:>column$}
 
 {}
             "#,
@@ -68,7 +68,7 @@ impl<'i> TechniqueError<'i> {
         let j = calculate_column_number(self.source, self.offset);
 
         let line = i + 1;
-        let column = j;
+        let column = j + 1;
 
         format!(
             "{}: {}:{}:{} {}",
@@ -103,8 +103,18 @@ fn calculate_line_number(content: &str, offset: usize) -> usize {
 fn calculate_column_number(content: &str, offset: usize) -> usize {
     let before = &content[..offset];
     match before.rfind('\n') {
-        Some(start) => offset - start,
-        None => offset,
+        Some(start) => {
+            // Count Unicode characters from the start of the line to the offset
+            content[start + 1..offset]
+                .chars()
+                .count()
+        }
+        None => {
+            // No newline found, count characters from the beginning
+            before
+                .chars()
+                .count()
+        }
     }
 }
 
@@ -136,6 +146,35 @@ test
             .unwrap();
         assert_eq!(after, "test");
     }
+
+    #[test]
+    fn counting_columns_ascii() {
+        let content = "This is a test";
+
+        let col = calculate_column_number(content, 5);
+        assert_eq!(col, 5); // After "This "
+    }
+
+    #[test]
+    fn counting_columns_unicode() {
+        // Test with Unicode characters like those in Three.t: "3.0 × 10⁸ m_s"
+        let content = "3.0 × 10⁸ m_s";
+
+        // At the underscore (× and ⁸ are multi-byte Unicode chars)
+        let offset = "3.0 × 10⁸ m".len();
+        let col = calculate_column_number(content, offset);
+        assert_eq!(col, 11); // Should count 11 characters, not bytes
+    }
+
+    #[test]
+    fn counting_columns_multiline() {
+        let content = "First line\nSecond × line";
+
+        // After "Second " on second line (× is multi-byte)
+        let offset = "First line\n".len();
+        let col = calculate_column_number(content, offset + 7);
+        assert_eq!(col, 7);
+    }
 }
 
 #[derive(Debug)]

src/formatting/formatter.rs

@@ -822,7 +822,7 @@ impl Formatter {
     fn append_numeric(&mut self, numeric: &Numeric) {
         match numeric {
             Numeric::Integral(num) => self.append(Syntax::Numeric, &num.to_string()),
-            Numeric::Scientific(_) => todo!(),
+            Numeric::Scientific(quantity) => self.append(Syntax::Numeric, &quantity.to_string()),
         }
     }
 

src/language/mod.rs

@@ -1,6 +1,8 @@
 // Types representing the Technique procedures language
 
+mod quantity;
 mod types;
 
 // Re-export all public symbols
+pub use quantity::*;
 pub use types::*;