rt-format 0.3.1

Fully-runtime equivalent of the format! macro
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

// TODO: Find a way to avoid code duplication between this and the example code in lib.rs docs.

use std::cmp::PartialEq;
use std::convert::TryInto;
use std::fmt;

use rt_format::{Format, FormatArgument, Specifier};

#[derive(Debug, PartialEq)]
#[allow(dead_code)]
pub enum Variant {
    Int(i32),
    Float(f64),
}

impl FormatArgument for Variant {
    fn supports_format(&self, spec: &Specifier) -> bool {
        match self {
            Self::Int(_) => true,
            Self::Float(_) => match spec.format {
                Format::Display | Format::Debug | Format::LowerExp | Format::UpperExp => true,
                _ => false,
            },
        }
    }

    fn fmt_display(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Int(val) => fmt::Display::fmt(&val, f),
            Self::Float(val) => fmt::Display::fmt(&val, f),
        }
    }

    fn fmt_debug(&self, f: &mut fmt::Formatter) -> fmt::Result {
        fmt::Debug::fmt(self, f)
    }

    fn fmt_octal(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Int(val) => fmt::Octal::fmt(&val, f),
            _ => Err(fmt::Error),
        }
    }

    fn fmt_lower_hex(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Int(val) => fmt::LowerHex::fmt(&val, f),
            _ => Err(fmt::Error),
        }
    }

    fn fmt_upper_hex(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Int(val) => fmt::UpperHex::fmt(&val, f),
            _ => Err(fmt::Error),
        }
    }

    fn fmt_binary(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Int(val) => fmt::Binary::fmt(&val, f),
            _ => Err(fmt::Error),
        }
    }

    fn fmt_lower_exp(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Int(val) => fmt::LowerExp::fmt(&val, f),
            Self::Float(val) => fmt::LowerExp::fmt(&val, f),
        }
    }

    fn fmt_upper_exp(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Int(val) => fmt::UpperExp::fmt(&val, f),
            Self::Float(val) => fmt::UpperExp::fmt(&val, f),
        }
    }

    fn to_usize(&self) -> Result<usize, ()> {
        match self {
            Variant::Int(val) => (*val).try_into().map_err(|_| ()),
            Variant::Float(_) => Err(()),
        }
    }
}