icydb-schema 0.219.0

Bounded public schema proposal contract for IcyDB
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140

use crate::decimal::{Decimal, ParseDecimalError, ParseDecimalErrorReason};
use std::{
    fmt::{Display, Formatter},
    str::FromStr,
};

impl Display for Decimal {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        let (mantissa, scale) = self.normalized_parts();

        if mantissa == 0 {
            return f.write_str("0");
        }

        let negative = mantissa.is_negative();
        let mut digits = mantissa.unsigned_abs().to_string();

        if scale == 0 {
            if negative {
                return write!(f, "-{digits}");
            }

            return f.write_str(&digits);
        }

        let scale_usize = usize::try_from(scale).map_err(|_| std::fmt::Error)?;

        if digits.len() <= scale_usize {
            let zeros = "0".repeat(scale_usize - digits.len());
            let body = format!("0.{zeros}{digits}");
            if negative {
                write!(f, "-{body}")
            } else {
                f.write_str(&body)
            }
        } else {
            let split = digits.len() - scale_usize;
            let frac = digits.split_off(split);
            if negative {
                write!(f, "-{digits}.{frac}")
            } else {
                write!(f, "{digits}.{frac}")
            }
        }
    }
}

impl FromStr for Decimal {
    type Err = ParseDecimalError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        // Phase 1: parse sign.
        let input = s.trim();
        if input.is_empty() {
            return Err(ParseDecimalError::new(ParseDecimalErrorReason::Empty));
        }

        let (negative, unsigned) = if let Some(rest) = input.strip_prefix('-') {
            (true, rest)
        } else if let Some(rest) = input.strip_prefix('+') {
            (false, rest)
        } else {
            (false, input)
        };

        // Exponent notation is intentionally unsupported for predictable decimal
        // parsing semantics in 0.23.
        if unsigned.contains(['e', 'E']) {
            return Err(ParseDecimalError::new(
                ParseDecimalErrorReason::ExponentNotationUnsupported,
            ));
        }

        // Phase 2: parse base-10 digits and decimal point.
        let (int_digits, frac_digits) = split_decimal_significand(unsigned)?;
        let combined = format!("{int_digits}{frac_digits}");
        let combined = strip_leading_zeros(&combined);

        let scale_i64 = i64::try_from(frac_digits.len()).map_err(|_| {
            ParseDecimalError::new(ParseDecimalErrorReason::FractionalLengthOverflow)
        })?;
        let digits = combined.to_string();

        let scale = u32::try_from(scale_i64)
            .map_err(|_| ParseDecimalError::new(ParseDecimalErrorReason::ScaleOverflow))?;

        // Phase 3: materialize mantissa without floating-point fallback.
        let signed_digits = if negative {
            format!("-{digits}")
        } else {
            digits
        };
        let mantissa = signed_digits
            .parse::<i128>()
            .map_err(|_| ParseDecimalError::new(ParseDecimalErrorReason::MantissaOverflow))?;

        Self::checked_from_mantissa_scale(mantissa, scale).ok_or_else(|| {
            ParseDecimalError::new(ParseDecimalErrorReason::ScaleExceedsSupportedRange)
        })
    }
}

fn split_decimal_significand(input: &str) -> Result<(&str, &str), ParseDecimalError> {
    let mut segments = input.split('.');
    let int_digits = segments
        .next()
        .ok_or_else(|| ParseDecimalError::new(ParseDecimalErrorReason::InvalidSignificand))?;
    let frac_digits = segments.next().unwrap_or("");

    if segments.next().is_some() {
        return Err(ParseDecimalError::new(
            ParseDecimalErrorReason::InvalidSignificand,
        ));
    }

    if int_digits.is_empty() && frac_digits.is_empty() {
        return Err(ParseDecimalError::new(
            ParseDecimalErrorReason::InvalidSignificand,
        ));
    }

    if !int_digits.chars().all(|c| c.is_ascii_digit()) {
        return Err(ParseDecimalError::new(
            ParseDecimalErrorReason::InvalidDigits,
        ));
    }

    if !frac_digits.chars().all(|c| c.is_ascii_digit()) {
        return Err(ParseDecimalError::new(
            ParseDecimalErrorReason::InvalidDigits,
        ));
    }

    Ok((int_digits, frac_digits))
}

fn strip_leading_zeros(digits: &str) -> &str {
    let trimmed = digits.trim_start_matches('0');
    if trimmed.is_empty() { "0" } else { trimmed }
}