v/vlib/compiler/tests/generic_test.v

132 lines
2.0 KiB
V

fn simple<T>(p T) T {
return p
}
fn sum<T>(l []T) T {
mut r := T(0)
for e in l {
r += e
}
return r
}
fn map_f<T,U>(l []T, f fn(T)U) []U {
mut r := []U
for e in l {
r << f(e)
}
return r
}
fn foldl<T>(l []T, nil T, f fn(T,T)T) T {
mut r := nil
for e in l {
r = f(r, e)
}
return r
}
fn plus<T>(a T, b T) T {
return a+b
}
fn square(x int) int {
return x*x
}
fn mul_int(x int, y int) int {
return x*y
}
fn assert_eq<T>(a, b T) {
r := a == b
println('$a == $b: ${r.str()}')
assert r
}
fn print_nice<T>(x T, indent int) {
mut space := ''
for _ in 0..indent {
space = space + ' '
}
println('$space$x')
}
fn test_generic_fn() {
assert_eq(simple(0+1), 1)
assert_eq(simple('g') + 'h', 'gh')
assert_eq(sum([5.1,6.2,7.0]), 18.3)
assert_eq(plus(i64(4), i64(6)), i64(10))
a := [1,2,3,4]
b := map_f(a, square)
assert_eq(sum(b), 30) // 1+4+9+16 = 30
assert_eq(foldl(b, 1, mul_int), 576) // 1*4*9*16 = 576
print_nice('str', 8)
}
struct Point {
mut:
x f64
y f64
}
fn (p mut Point) translate<T>(x, y T) {
p.x += x
p.y += y
}
fn test_generic_method() {
mut p := Point{}
p.translate(2, 1.0)
assert p.x == 2.0 && p.y == 1.0
}
fn get_values<T>(i T) []T {
return [i]
}
fn test_generic_fn_in_for_in_expression() {
for value in get_values(1) {
assert value == 1
}
for i, val in get_values(0) {
assert i == val
}
for value in get_values('a') {
assert value == 'a'
}
}
// test generic struct
struct DB {
driver string
}
struct User {
db DB
mut:
name string
}
struct Repo<T> {
db DB
mut:
model T
}
fn new_repo<U>(db DB) Repo<U> {
return Repo<U>{db: db}
}
fn test_generic_struct() {
mut a := new_repo<User>(DB{})
a.model.name = 'joe'
mut b := Repo<User>{db: DB{}}
b.model.name = 'joe'
assert a.model.name == 'joe'
assert b.model.name == 'joe'
}