goish 0.20.7

Goish Rust — write Rust using Go idioms. Ports Go's standard library and syntax so Go programmers can write Rust code that reads and feels like Go.
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

//! maps: Go's maps package — generic map operations.
//!
//!   Go                                  goish
//!   ─────────────────────────────────   ──────────────────────────────────
//!   maps.Keys(m)                        maps::Keys(&m)      — Vec<K>
//!   maps.Values(m)                      maps::Values(&m)    — Vec<V>
//!   maps.Equal(m1, m2)                  maps::Equal(&m1, &m2)
//!   maps.Clone(m)                       maps::Clone(&m)
//!   maps.Copy(dst, src)                 maps::Copy(&mut dst, &src)
//!   maps.DeleteFunc(m, f)               maps::DeleteFunc(&mut m, f)
//!
//! Go 1.23 changed `Keys` / `Values` to return an `iter.Seq`; goish
//! returns a `Vec` for simpler call sites. The order is arbitrary (as
//! in Go).

use crate::types::map;
use std::hash::Hash;

/// `maps.Keys(m)` — collect keys into a Vec (order is arbitrary).
#[allow(non_snake_case)]
pub fn Keys<K: Clone + Eq + Hash, V>(m: &map<K, V>) -> Vec<K> {
    m.keys().cloned().collect()
}

/// `maps.Values(m)` — collect values into a Vec (order is arbitrary).
#[allow(non_snake_case)]
pub fn Values<K: Eq + Hash, V: Clone>(m: &map<K, V>) -> Vec<V> {
    m.values().cloned().collect()
}

/// `maps.Equal(m1, m2)` — equal iff same keys and equal values.
#[allow(non_snake_case)]
pub fn Equal<K: Eq + Hash, V: PartialEq>(m1: &map<K, V>, m2: &map<K, V>) -> bool {
    if m1.len() != m2.len() { return false; }
    for (k, v1) in m1 {
        match m2.get(k) {
            Some(v2) if v1 == v2 => {}
            _ => return false,
        }
    }
    true
}

/// `maps.EqualFunc(m1, m2, eq)` — equality using custom value comparator.
#[allow(non_snake_case)]
pub fn EqualFunc<K: Eq + Hash, V1, V2, F: Fn(&V1, &V2) -> bool>(
    m1: &map<K, V1>, m2: &map<K, V2>, eq: F,
) -> bool {
    if m1.len() != m2.len() { return false; }
    for (k, v1) in m1 {
        match m2.get(k) {
            Some(v2) if eq(v1, v2) => {}
            _ => return false,
        }
    }
    true
}

/// `maps.Clone(m)` — shallow clone of every (key, value).
#[allow(non_snake_case)]
pub fn Clone<K: Clone + Eq + Hash, V: Clone>(m: &map<K, V>) -> map<K, V> {
    m.clone()
}

/// `maps.Copy(dst, src)` — inserts every (k, v) from src into dst,
/// overwriting on conflict.
#[allow(non_snake_case)]
pub fn Copy<K: Clone + Eq + Hash, V: Clone>(dst: &mut map<K, V>, src: &map<K, V>) {
    for (k, v) in src { dst.insert(k.clone(), v.clone()); }
}

/// `maps.DeleteFunc(m, del)` — removes every (k, v) where del(k, v) is true.
#[allow(non_snake_case)]
pub fn DeleteFunc<K: Eq + Hash, V, F: FnMut(&K, &V) -> bool>(
    m: &mut map<K, V>, mut del: F,
) {
    m.retain(|k, v| !del(k, v));
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn keys_and_values() {
        let mut m: map<&str, i64> = map::new();
        m.insert("a", 1);
        m.insert("b", 2);
        let mut ks = Keys(&m);
        ks.sort();
        assert_eq!(ks, vec!["a", "b"]);
        let mut vs = Values(&m);
        vs.sort();
        assert_eq!(vs, vec![1, 2]);
    }

    #[test]
    fn equal_and_clone() {
        let mut a: map<i64, i64> = map::new();
        a.insert(1, 10);
        a.insert(2, 20);
        let b = Clone(&a);
        assert!(Equal(&a, &b));
        let mut c = a.clone();
        c.insert(3, 30);
        assert!(!Equal(&a, &c));
    }

    #[test]
    fn copy_merges() {
        let mut dst: map<i64, i64> = map::new();
        dst.insert(1, 10);
        let mut src: map<i64, i64> = map::new();
        src.insert(2, 20);
        src.insert(1, 99);  // should overwrite
        Copy(&mut dst, &src);
        assert_eq!(dst.get(&1), Some(&99));
        assert_eq!(dst.get(&2), Some(&20));
    }

    #[test]
    fn delete_func_removes() {
        let mut m: map<i64, i64> = map::new();
        for i in 1..=5i64 { m.insert(i, i * 10); }
        DeleteFunc(&mut m, |k, _| *k % 2 == 0);
        assert_eq!(m.len(), 3);
        assert!(m.contains_key(&1));
        assert!(!m.contains_key(&2));
    }
}