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
use std::str::FromStr;
const DEFAULT_AMP: f32 = 25.0;
const DEFAULT_LAMBDA: f32 = 50.0;
const DEFAULT_CENTER: (f32, f32) = (0.5, 0.5);
const DEFAULT_SINE: Shape = Shape::Sine {
amplitude: DEFAULT_AMP,
lambda: DEFAULT_LAMBDA,
offset: 0.0,
};
const DEFAULT_ELL: Shape = Shape::Ellipse {
eccentricity: 0.0,
center: DEFAULT_CENTER,
};
pub enum Shape {
Linear,
Sine {
amplitude: f32,
lambda: f32,
offset: f32,
},
Ellipse {
eccentricity: f32,
center: (f32, f32),
},
#[doc(hidden)]
__Nonexhaustive,
}
impl Default for Shape {
fn default() -> Self {
Shape::Linear
}
}
fn unwrap_parens(s: &str) -> Result<&str, ()> {
let st = s.trim();
if st.starts_with('(') && st.ends_with(')')
|| st.starts_with('[') && st.ends_with(']')
|| st.starts_with('{') && st.ends_with('}')
|| st.starts_with('<') && st.ends_with('>')
{
Ok(&st[1..st.len() - 1])
} else {
Err(())
}
}
impl FromStr for Shape {
type Err = String;
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s.trim() {
"" | "line" | "linear" => Ok(Shape::Linear),
"sine" => Ok(DEFAULT_SINE),
"circle" | "ellipse" => Ok(DEFAULT_ELL),
st => {
let err_msg = format!("Could not parse `{}` as a valid path shape", st);
if st.starts_with("sine") {
let args = unwrap_parens(&st[4..])
.map_err(|_| err_msg.clone())?
.split(',')
.map(|a| a.trim().parse::<f32>())
.collect::<Result<Vec<_>, _>>()
.map_err(|_| err_msg.clone())?;
match args.len() {
0 => Ok(DEFAULT_SINE),
1 => Ok(Shape::Sine {
amplitude: args[0],
lambda: DEFAULT_LAMBDA,
offset: 0.0,
}),
2 => Ok(Shape::Sine {
amplitude: args[0],
lambda: args[1],
offset: 0.0,
}),
3 => Ok(Shape::Sine {
amplitude: args[0],
lambda: args[1],
offset: args[2],
}),
_ => Err(err_msg),
}
} else if st.starts_with("circle") {
let args = unwrap_parens(&st[6..])
.map_err(|_| err_msg.clone())?
.split(',')
.map(|a| a.trim().parse::<f32>())
.collect::<Result<Vec<_>, _>>()
.map_err(|_| err_msg.clone())?;
match args.len() {
0 => Ok(DEFAULT_ELL),
2 => Ok(Shape::Ellipse {
eccentricity: 0.0,
center: (args[0], args[1]),
}),
_ => Err(err_msg),
}
} else if st.starts_with("ellipse") {
let args = unwrap_parens(&st[7..])
.map_err(|_| err_msg.clone())?
.split(',')
.map(|a| a.trim().parse::<f32>())
.collect::<Result<Vec<_>, _>>()
.map_err(|_| err_msg.clone())?;
match args.len() {
0 => Ok(DEFAULT_ELL),
1 => Ok(Shape::Ellipse {
eccentricity: args[0],
center: DEFAULT_CENTER,
}),
2 => Ok(Shape::Ellipse {
eccentricity: 0.0,
center: (args[0], args[1]),
}),
3 => Ok(Shape::Ellipse {
eccentricity: args[0],
center: (args[1], args[2]),
}),
_ => Err(err_msg),
}
} else {
Err(err_msg)
}
}
}
}
}