seq: Parse integral and fractional number of digits in the same function

A lot of the code can be shared, and parsing is quite straightforward
as we know that the digit is somewhat valid.

src/uu/seq/src/hexadecimalfloat.rs

@@ -1,206 +0,0 @@
-// This file is part of the uutils coreutils package.
-//
-// For the full copyright and license information, please view the LICENSE
-// file that was distributed with this source code.
-// spell-checker:ignore extendedbigdecimal bigdecimal hexdigit numberparse
-
-// TODO: Rewrite this
-// Detect number precision similar to GNU coreutils. Refer to scan_arg in seq.c. There are still
-// some differences from the GNU version, but this should be sufficient to test the idea.
-pub fn parse_precision(s: &str) -> Option<usize> {
-    let hex_index = s.find(['x', 'X']);
-    let point_index = s.find('.');
-
-    if hex_index.is_some() {
-        // Hex value. Returns:
-        // - 0 for a hexadecimal integer (filled above)
-        // - None for a hexadecimal floating-point number (the default value of precision)
-        let power_index = s.find(['p', 'P']);
-        if point_index.is_none() && power_index.is_none() {
-            // No decimal point and no 'p' (power) => integer => precision = 0
-            return Some(0);
-        } else {
-            return None;
-        }
-    }
-
-    // This is a decimal floating point. The precision depends on two parameters:
-    // - the number of fractional digits
-    // - the exponent
-    // Let's detect the number of fractional digits
-    let fractional_length = if let Some(point_index) = point_index {
-        s[point_index + 1..]
-            .chars()
-            .take_while(|c| c.is_ascii_digit())
-            .count()
-    } else {
-        0
-    };
-
-    let mut precision = Some(fractional_length);
-
-    // Let's update the precision if exponent is present
-    if let Some(exponent_index) = s.find(['e', 'E']) {
-        let exponent_value: i32 = s[exponent_index + 1..].parse().unwrap_or(0);
-        if exponent_value < 0 {
-            precision = precision.map(|p| p + exponent_value.unsigned_abs() as usize);
-        } else {
-            precision = precision.map(|p| p - p.min(exponent_value as usize));
-        }
-    }
-    precision
-}
-
-/* TODO: move tests
-#[cfg(test)]
-mod tests {
-
-    use super::{parse_number, parse_precision};
-    use crate::{ExtendedBigDecimal, numberparse::ParseNumberError};
-    use bigdecimal::BigDecimal;
-    use num_traits::ToPrimitive;
-
-    fn parse_big_decimal(s: &str) -> Result<BigDecimal, ParseNumberError> {
-        match parse_number(s)?.number {
-            ExtendedBigDecimal::BigDecimal(bd) => Ok(bd),
-            _ => Err(ParseNumberError::Float),
-        }
-    }
-
-    fn parse_f64(s: &str) -> Result<f64, ParseNumberError> {
-        parse_big_decimal(s)?
-            .to_f64()
-            .ok_or(ParseNumberError::Float)
-    }
-
-    #[test]
-    fn test_parse_precise_number_case_insensitive() {
-        assert_eq!(parse_f64("0x1P1").unwrap(), 2.0);
-        assert_eq!(parse_f64("0x1p1").unwrap(), 2.0);
-    }
-
-    #[test]
-    fn test_parse_precise_number_plus_minus_prefixes() {
-        assert_eq!(parse_f64("+0x1p1").unwrap(), 2.0);
-        assert_eq!(parse_f64("-0x1p1").unwrap(), -2.0);
-    }
-
-    #[test]
-    fn test_parse_precise_number_power_signs() {
-        assert_eq!(parse_f64("0x1p1").unwrap(), 2.0);
-        assert_eq!(parse_f64("0x1p+1").unwrap(), 2.0);
-        assert_eq!(parse_f64("0x1p-1").unwrap(), 0.5);
-    }
-
-    #[test]
-    fn test_parse_precise_number_hex() {
-        assert_eq!(parse_f64("0xd.dp-1").unwrap(), 6.90625);
-    }
-
-    #[test]
-    fn test_parse_precise_number_no_power() {
-        assert_eq!(parse_f64("0x123.a").unwrap(), 291.625);
-    }
-
-    #[test]
-    fn test_parse_precise_number_no_fractional() {
-        assert_eq!(parse_f64("0x333p-4").unwrap(), 51.1875);
-    }
-
-    #[test]
-    fn test_parse_precise_number_no_integral() {
-        assert_eq!(parse_f64("0x.9").unwrap(), 0.5625);
-        assert_eq!(parse_f64("0x.9p2").unwrap(), 2.25);
-    }
-
-    #[test]
-    fn test_parse_precise_number_from_valid_values() {
-        assert_eq!(parse_f64("0x1p1").unwrap(), 2.0);
-        assert_eq!(parse_f64("+0x1p1").unwrap(), 2.0);
-        assert_eq!(parse_f64("-0x1p1").unwrap(), -2.0);
-        assert_eq!(parse_f64("0x1p-1").unwrap(), 0.5);
-        assert_eq!(parse_f64("0x1.8").unwrap(), 1.5);
-        assert_eq!(parse_f64("-0x1.8").unwrap(), -1.5);
-        assert_eq!(parse_f64("0x1.8p2").unwrap(), 6.0);
-        assert_eq!(parse_f64("0x1.8p+2").unwrap(), 6.0);
-        assert_eq!(parse_f64("0x1.8p-2").unwrap(), 0.375);
-        assert_eq!(parse_f64("0x.8").unwrap(), 0.5);
-        assert_eq!(parse_f64("0x10p0").unwrap(), 16.0);
-        assert_eq!(parse_f64("0x0.0").unwrap(), 0.0);
-        assert_eq!(parse_f64("0x0p0").unwrap(), 0.0);
-        assert_eq!(parse_f64("0x0.0p0").unwrap(), 0.0);
-        assert_eq!(parse_f64("-0x.1p-3").unwrap(), -0.0078125);
-        assert_eq!(parse_f64("-0x.ep-3").unwrap(), -0.109375);
-    }
-
-    #[test]
-    fn test_parse_float_from_invalid_values() {
-        let expected_error = ParseNumberError::Float;
-        assert_eq!(parse_f64("").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("1").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("1p").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0xG").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0xp").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0xp3").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1.").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1p").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1p+").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("-0xx1p1").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1.k").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("-0x1pa").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1.1pk").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1.8p2z").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("0x1p3.2").unwrap_err(), expected_error);
-        assert_eq!(parse_f64("-0x.ep-3z").unwrap_err(), expected_error);
-    }
-
-    #[test]
-    fn test_parse_precise_number_count_digits() {
-        let precise_num = parse_number("0x1.2").unwrap(); // 1.125 decimal
-        assert_eq!(precise_num.num_integral_digits, 1);
-        assert_eq!(precise_num.num_fractional_digits, 3);
-
-        let precise_num = parse_number("-0x1.2").unwrap(); // -1.125 decimal
-        assert_eq!(precise_num.num_integral_digits, 2);
-        assert_eq!(precise_num.num_fractional_digits, 3);
-
-        let precise_num = parse_number("0x123.8").unwrap(); // 291.5 decimal
-        assert_eq!(precise_num.num_integral_digits, 3);
-        assert_eq!(precise_num.num_fractional_digits, 1);
-
-        let precise_num = parse_number("-0x123.8").unwrap(); // -291.5 decimal
-        assert_eq!(precise_num.num_integral_digits, 4);
-        assert_eq!(precise_num.num_fractional_digits, 1);
-    }
-
-    #[test]
-    fn test_parse_precision_valid_values() {
-        assert_eq!(parse_precision("1"), Some(0));
-        assert_eq!(parse_precision("0x1"), Some(0));
-        assert_eq!(parse_precision("0x1.1"), None);
-        assert_eq!(parse_precision("0x1.1p2"), None);
-        assert_eq!(parse_precision("0x1.1p-2"), None);
-        assert_eq!(parse_precision(".1"), Some(1));
-        assert_eq!(parse_precision("1.1"), Some(1));
-        assert_eq!(parse_precision("1.12"), Some(2));
-        assert_eq!(parse_precision("1.12345678"), Some(8));
-        assert_eq!(parse_precision("1.12345678e-3"), Some(11));
-        assert_eq!(parse_precision("1.1e-1"), Some(2));
-        assert_eq!(parse_precision("1.1e-3"), Some(4));
-    }
-
-    #[test]
-    fn test_parse_precision_invalid_values() {
-        // Just to make sure it doesn't crash on incomplete values/bad format
-        // Good enough for now.
-        assert_eq!(parse_precision("1."), Some(0));
-        assert_eq!(parse_precision("1e"), Some(0));
-        assert_eq!(parse_precision("1e-"), Some(0));
-        assert_eq!(parse_precision("1e+"), Some(0));
-        assert_eq!(parse_precision("1em"), Some(0));
-    }
-}
-*/

src/uu/seq/src/numberparse.rs

@@ -9,11 +9,9 @@
 //! [`PreciseNumber`] struct.
 use std::str::FromStr;
 
-use bigdecimal::BigDecimal;
-use num_traits::Zero;
 use uucore::format::num_parser::{ExtendedParser, ExtendedParserError};
 
-use crate::{hexadecimalfloat, number::PreciseNumber};
+use crate::number::PreciseNumber;
 use uucore::format::ExtendedBigDecimal;
 
 /// An error returned when parsing a number fails.
@@ -23,10 +21,11 @@ pub enum ParseNumberError {
     Nan,
 }
 
-// Compute the number of integral digits in input string. We know that the
+// Compute the number of integral and fractional digits in input string,
-// string has already been parsed correctly, so we don't need to be too
+// and wrap the result in a PreciseNumber.
-// careful.
+// We know that the string has already been parsed correctly, so we don't
-fn compute_num_integral_digits(input: &str, _number: &BigDecimal) -> usize {
+// need to be too careful.
+fn compute_num_digits(input: &str, ebd: ExtendedBigDecimal) -> PreciseNumber {
     let input = input.to_lowercase();
     let mut input = input.trim_start();
 
@@ -35,9 +34,20 @@ fn compute_num_integral_digits(input: &str, _number: &BigDecimal) -> usize {
         input = trimmed;
     }
 
-    // Integral digits for an hex number is ill-defined.
+    // Integral digits for any hex number is ill-defined (0 is fine as an output)
+    // Fractional digits for an floating hex number is ill-defined, return None
+    // as we'll totally ignore that number for precision computations.
+    // Still return 0 for hex integers though.
     if input.starts_with("0x") || input.starts_with("-0x") {
-        return 0;
+        return PreciseNumber {
+            number: ebd,
+            num_integral_digits: 0,
+            num_fractional_digits: if input.contains(".") || input.contains("p") {
+                None
+            } else {
+                Some(0)
+            },
+        };
     }
 
     // Split the exponent part, if any
@@ -45,17 +55,19 @@ fn compute_num_integral_digits(input: &str, _number: &BigDecimal) -> usize {
     debug_assert!(parts.len() <= 2);
 
     // Count all the digits up to `.`, `-` sign is included.
-    let digits: usize = match parts[0].find(".") {
+    let (mut int_digits, mut frac_digits) = match parts[0].find(".") {
         Some(i) => {
             // Cover special case .X and -.X where we behave as if there was a leading 0:
             // 0.X, -0.X.
-            match i {
+            let int_digits = match i {
                 0 => 1,
                 1 if parts[0].starts_with("-") => 2,
                 _ => i,
-            }
+            };
+
+            (int_digits, parts[0].len() - i - 1)
         }
-        None => parts[0].len(),
+        None => (parts[0].len(), 0),
     };
 
     // If there is an exponent, reparse that (yes this is not optimal,
@@ -63,14 +75,22 @@ fn compute_num_integral_digits(input: &str, _number: &BigDecimal) -> usize {
     if parts.len() == 2 {
         let exp = parts[1].parse::<i64>().unwrap_or(0);
         // For positive exponents, effectively expand the number. Ignore negative exponents.
-        // Also ignore overflowed exponents (default 0 above).
+        // Also ignore overflowed exponents (unwrap_or(0)).
         if exp > 0 {
-            digits + exp as usize
+            int_digits += exp.try_into().unwrap_or(0)
+        };
+        frac_digits = if exp < frac_digits as i64 {
+            // Subtract from i128 to avoid any overflow
+            (frac_digits as i128 - exp as i128).try_into().unwrap_or(0)
         } else {
-            digits
+            0
         }
-    } else {
+    }
-        digits
+
+    PreciseNumber {
+        number: ebd,
+        num_integral_digits: int_digits,
+        num_fractional_digits: Some(frac_digits),
     }
 }
 
@@ -80,36 +100,29 @@ impl FromStr for PreciseNumber {
     type Err = ParseNumberError;
     fn from_str(input: &str) -> Result<Self, Self::Err> {
         let ebd = match ExtendedBigDecimal::extended_parse(input) {
-            Ok(ebd) => ebd,
+            Ok(ebd) => match ebd {
+                // Handle special values
+                ExtendedBigDecimal::BigDecimal(_) | ExtendedBigDecimal::MinusZero => {
+                    // TODO: GNU `seq` treats small numbers < 1e-4950 as 0, we could do the same
+                    // to avoid printing senselessly small numbers.
+                    ebd
+                }
+                ExtendedBigDecimal::Infinity | ExtendedBigDecimal::MinusInfinity => {
+                    return Ok(PreciseNumber {
+                        number: ebd,
+                        num_integral_digits: 0,
+                        num_fractional_digits: Some(0),
+                    });
+                }
+                ExtendedBigDecimal::Nan | ExtendedBigDecimal::MinusNan => {
+                    return Err(ParseNumberError::Nan);
+                }
+            },
             Err(ExtendedParserError::Underflow(ebd)) => ebd, // Treat underflow as 0
             Err(_) => return Err(ParseNumberError::Float),
         };
 
-        // Handle special values, get a BigDecimal to help digit-counting.
+        Ok(compute_num_digits(input, ebd))
-        let bd = match ebd {
-            ExtendedBigDecimal::Infinity | ExtendedBigDecimal::MinusInfinity => {
-                return Ok(PreciseNumber {
-                    number: ebd,
-                    num_integral_digits: 0,
-                    num_fractional_digits: Some(0),
-                });
-            }
-            ExtendedBigDecimal::Nan | ExtendedBigDecimal::MinusNan => {
-                return Err(ParseNumberError::Nan);
-            }
-            ExtendedBigDecimal::BigDecimal(ref bd) => {
-                // TODO: `seq` treats small numbers < 1e-4950 as 0, we could do the same
-                // to avoid printing senselessly small numbers.
-                bd.clone()
-            }
-            ExtendedBigDecimal::MinusZero => BigDecimal::zero(),
-        };
-
-        Ok(PreciseNumber {
-            number: ebd,
-            num_integral_digits: compute_num_integral_digits(input, &bd),
-            num_fractional_digits: hexadecimalfloat::parse_precision(input),
-        })
     }
 }
 

src/uu/seq/src/seq.rs

@@ -15,7 +15,6 @@ use uucore::format::{ExtendedBigDecimal, Format, num_format};
 use uucore::{format_usage, help_about, help_usage};
 
 mod error;
-mod hexadecimalfloat;
 
 // public to allow fuzzing
 #[cfg(fuzzing)]