1# Tests of Starlark 'struct' extension.
2# This is not a standard feature and the Go and Starlark APIs may yet change.
3
4load("assert.star", "assert")
5
6assert.eq(str(struct), "<built-in function struct>")
7
8# struct is a constructor for "unbranded" structs.
9s = struct(host = "localhost", port = 80)
10assert.eq(s, s)
11assert.eq(s, struct(host = "localhost", port = 80))
12assert.ne(s, struct(host = "localhost", port = 81))
13assert.eq(type(s), "struct")
14assert.eq(str(s), 'struct(host = "localhost", port = 80)')
15assert.eq(s.host, "localhost")
16assert.eq(s.port, 80)
17assert.fails(lambda : s.protocol, "struct has no .protocol attribute")
18assert.eq(dir(s), ["host", "port"])
19
20# Use gensym to create "branded" struct types.
21hostport = gensym(name = "hostport")
22assert.eq(type(hostport), "symbol")
23assert.eq(str(hostport), "hostport")
24
25# Call the symbol to instantiate a new type.
26http = hostport(host = "localhost", port = 80)
27assert.eq(type(http), "struct")
28assert.eq(str(http), 'hostport(host = "localhost", port = 80)') # includes name of constructor
29assert.eq(http, http)
30assert.eq(http, hostport(host = "localhost", port = 80))
31assert.ne(http, hostport(host = "localhost", port = 443))
32assert.eq(http.host, "localhost")
33assert.eq(http.port, 80)
34assert.fails(lambda : http.protocol, "hostport struct has no .protocol attribute")
35
36person = gensym(name = "person")
37bob = person(name = "bob", age = 50)
38alice = person(name = "alice", city = "NYC")
39assert.ne(http, bob) # different constructor symbols
40assert.ne(bob, alice) # different fields
41
42hostport2 = gensym(name = "hostport")
43assert.eq(hostport, hostport)
44assert.ne(hostport, hostport2) # same name, different symbol
45assert.ne(http, hostport2(host = "localhost", port = 80)) # equal fields but different ctor symbols
46
47# dir
48assert.eq(dir(alice), ["city", "name"])
49assert.eq(dir(bob), ["age", "name"])
50assert.eq(dir(http), ["host", "port"])
51
52# hasattr, getattr
53assert.true(hasattr(alice, "city"))
54assert.eq(hasattr(alice, "ageaa"), False)
55assert.eq(getattr(alice, "city"), "NYC")
56
57# +
58assert.eq(bob + bob, bob)
59assert.eq(bob + alice, person(age = 50, city = "NYC", name = "alice"))
60assert.eq(alice + bob, person(age = 50, city = "NYC", name = "bob")) # not commutative! a misfeature
61assert.fails(lambda : alice + 1, "struct \\+ int")
62assert.eq(http + http, http)
63assert.fails(lambda : http + bob, "different constructors: hostport \\+ person")
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