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
|
use std::num::ParseFloatError;
use std::str::FromStr;
use iced::Pixels;
use iced::advanced::text::LineHeight;
use super::Value;
#[derive(Debug, thiserror::Error, Clone, PartialEq)]
pub enum ParseLineHeightError {
#[error("float parsing error: {0}")]
ParseFloatError(ParseFloatError),
#[error("missing prefix")]
MissingPrefix,
#[error("invalid prefix")]
InvalidPrefix,
#[error("cannot parse line height from empty string")]
Empty,
}
impl From<ParseFloatError> for ParseLineHeightError {
fn from(value: ParseFloatError) -> Self {
Self::ParseFloatError(value)
}
}
impl Value for LineHeight {
type Err = ParseLineHeightError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
let s = s.trim();
if s.is_empty() {
return Err(ParseLineHeightError::Empty);
}
if s.starts_with(|c: char| !c.is_ascii_digit()) {
let (prefix, value) = s.split_at(1);
match prefix.to_lowercase().as_str() {
"r" => Ok(Self::Relative(f32::from_str(value)?)),
"a" => Ok(Self::Absolute(Pixels::from_str(value)?)),
_ => Err(ParseLineHeightError::InvalidPrefix),
}
} else {
Err(ParseLineHeightError::MissingPrefix)
}
}
fn to_string(&self) -> String {
match self {
Self::Relative(value) => format!("r{}", value),
Self::Absolute(value) => format!("a{}", value.0),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn can_parse_with_r_prefix() {
assert_eq!(
LineHeight::from_str(" r3.2"),
Ok(LineHeight::Relative(3.2))
);
assert_eq!(
LineHeight::from_str(" R6.5 "),
Ok(LineHeight::Relative(6.5))
)
}
#[test]
fn can_parse_with_a_prefix() {
assert_eq!(
LineHeight::from_str("a9.4 "),
Ok(LineHeight::Absolute(Pixels(9.4)))
);
assert_eq!(
LineHeight::from_str("A1.3"),
Ok(LineHeight::Absolute(Pixels(1.3)))
)
}
#[test]
fn cant_parse_with_missing_prefix() {
assert_eq!(
LineHeight::from_str("5.1"),
Err(ParseLineHeightError::MissingPrefix)
)
}
#[test]
fn cant_parse_invalid_prefix() {
assert_eq!(
LineHeight::from_str("g21"),
Err(ParseLineHeightError::InvalidPrefix)
)
}
#[test]
fn cant_parse_invalid_float() {
assert_eq!(
LineHeight::from_str("a2f"),
Err(ParseLineHeightError::ParseFloatError(
f32::from_str("2f").expect_err("float parse should fail")
))
)
}
#[test]
fn cant_parse_empty_string() {
assert_eq!(LineHeight::from_str(" "), Err(ParseLineHeightError::Empty))
}
}
|
