erg 0.6.53

The Erg programming language
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

f(x: Nat): Int = x
y: Ratio = f 1
# Erg's type checking does not necessarily enlarge the type. So this is OK.
z: Int = y
# But this is invalid.
invalid: 10..<20 = z #ERR

for! [(1, 2)], ((i, j),) =>
    k = i + 1 # OK
    print! k
for! [(1, 2)], ((i, j),) =>
    k = i + "a" # ERR
    print! k
for! zip([1], ["a"]), ((i: Int, s: Str),) =>
    k = i + 1
    l = s + "b"
    print! k, l
# ERR: i should be Int
for! zip([1], ["a"]), ((i: Str, s: Str),) => # ERR
    k = i + "a"
    print! k
for! zip([1], ["a"]), ((i, s),) =>
    k = i + "a" # ERR
    print! k
for! zip([1], ["a"]), (is) =>
    i = is[0]
    s = is[1]
    k = i + "a" # ERR
    _ = s + 1 # ERR
    print! k

for! zip([1+1], ["a"+"b"]), ((i, s),) => # i: Nat, s: Str
    print! i + 1
    print! s + "b"
    print! s + 1 # ERR
    print! i + "a" # ERR

for! "aaa", a =>
    print! a # OK
for! "aaa", a =>
    print! a + 1 # ERR

inty|T :> Nat, T <: Int|(x: T) = x + x
inty 0 # OK
inty 1.1 # ERR

_: List!({"a", "b"}, 2) = !["a", "b"] # OK
_: List!({"a", "b", "c"}, 2) = !["a", "b"] # OK
_: List!({"a", "c"}, 2) = !["a", "b"] # ERR
_: List!({"a"}, 2) = !["a", "b"] # ERR

ii _: Iterable(Iterable(Str)) = None
ii [1] # ERR
ii [[1]] # ERR
ii [["a"]]
ii ["aaa"] # Str <: Iterable Str