ahtml/
myfrom.rs

1// FUTURE: figure out how to inherit from `From` (and keep all the
2// existing From definitions for KString). It doesn't work out of the
3// box (various errors).
4pub trait MyFrom<T> {
5    fn myfrom(s: T) -> Self;
6}
7
8use std::borrow::Cow;
9
10use kstring::KString;
11
12// Can't do KString::from_static: no way to have a separate trait impl
13// for &'static.
14impl MyFrom<&str> for KString {
15    fn myfrom(s: &str) -> Self {
16        KString::from_ref(s)
17    }
18}
19
20impl MyFrom<&&str> for KString {
21    fn myfrom(s: &&str) -> Self {
22        KString::from_ref(*s)
23    }
24}
25
26impl MyFrom<&String> for KString {
27    fn myfrom(s: &String) -> Self {
28        KString::from_ref(s)
29    }
30}
31
32impl MyFrom<String> for KString {
33    fn myfrom(s: String) -> Self {
34        KString::from_string(s)
35    }
36}
37
38impl MyFrom<&KString> for KString {
39    fn myfrom(s: &KString) -> Self {
40        s.clone()
41    }
42}
43
44impl MyFrom<KString> for KString {
45    fn myfrom(s: KString) -> Self {
46        s
47    }
48}
49
50impl<'t> MyFrom<Cow<'t, str>> for KString {
51    fn myfrom(s: Cow<'t, str>) -> Self {
52        KString::from_ref(s.as_ref())
53    }
54}
55
56impl MyFrom<usize> for KString {
57    fn myfrom(val: usize) -> Self {
58        // exact size needed ?
59        // let mut buf: [u8; 32] = Default::default();
60        // let outp: &mut [u8] = &mut buf;
61        // let n = write!(outp, "{}", val).expect("enough space for the formatted number");
62        KString::from_string(val.to_string())
63    }
64}
65
66// impl<'t> MyFrom<HtmlString> for KString {
67//     fn myfrom(s: HtmlString) -> Self {
68//         let s2 = String::from_utf8(*s)?;
69//         KString::from_string(s2)
70//     }
71// }
72// Ah, cannot have errors here. So, do the conversion manually
73// outside, please.
74
75// ------------------------------------------------------------------
76
77impl MyFrom<&str> for String {
78    fn myfrom(s: &str) -> Self {
79        s.into()
80    }
81}
82
83impl MyFrom<&&str> for String {
84    fn myfrom(s: &&str) -> Self {
85        s.to_string()
86    }
87}
88
89impl MyFrom<&String> for String {
90    fn myfrom(s: &String) -> Self {
91        s.clone()
92    }
93}
94
95impl MyFrom<String> for String {
96    fn myfrom(s: String) -> Self {
97        s
98    }
99}
100
101impl MyFrom<&KString> for String {
102    fn myfrom(s: &KString) -> Self {
103        s.to_string()
104    }
105}
106
107impl MyFrom<KString> for String {
108    fn myfrom(s: KString) -> Self {
109        s.to_string()
110    }
111}
112
113impl<'t> MyFrom<Cow<'t, str>> for String {
114    fn myfrom(s: Cow<'t, str>) -> Self {
115        s.into()
116    }
117}
118
119impl MyFrom<usize> for String {
120    fn myfrom(val: usize) -> Self {
121        val.to_string()
122    }
123}
124
125// ------------------------------------------------------------------
126
127// / MyFrom must remain owned. Or chaining with MyAsStr as input type
128// / leads to non-owned output types combined with owned input
129// / types. (Does Rust never want From to lead to non-owned types,
130// / BTW?)  So we extend the trait here and add them if not chained
131// / with MyAsStr or similar.
132
133// pub trait MyFromInclStr<T> : MyFrom<T> {
134//     fn myfrom(s: T) -> Self;
135// }
136
137// impl<'s> MyFromInclStr<&'s str> for &'s str {
138//     fn myfrom(s: &'s str) -> Self {
139//         s
140//     }
141// }
142
143// impl<'s> MyFromInclStr<&&'s str> for &'s str {
144//     fn myfrom(s: &&'s str) -> Self {
145//         *s
146//     }
147// }
148
149// impl<'s> MyFromInclStr<&'s String> for &'s str {
150//     fn myfrom(s: &'s String) -> Self {
151//         s
152//     }
153// }
154
155// impl<'s> MyFromInclStr<&'s KString> for &'s str {
156//     fn myfrom(s: &'s KString) -> Self {
157//         s
158//     }
159// }
160
161// Damn. IS THIS WORKABLE now  just deal with no owned inputs?:
162// TODO: proper solution.
163
164impl<'s> MyFrom<&'s str> for &'s str {
165    fn myfrom(s: &'s str) -> Self {
166        s
167    }
168}
169
170impl<'s> MyFrom<&&'s str> for &'s str {
171    fn myfrom(s: &&'s str) -> Self {
172        *s
173    }
174}
175
176impl<'s> MyFrom<&'s String> for &'s str {
177    fn myfrom(s: &'s String) -> Self {
178        s
179    }
180}
181
182impl<'s> MyFrom<&'s KString> for &'s str {
183    fn myfrom(s: &'s KString) -> Self {
184        s
185    }
186}
ahtml/myfrom.rs

ahtml/
myfrom.rs
