Splats parameter with free variable bug

[firejox]

https://play.crystal-lang.org/#/r/2spc

def f(x, *y : *T) forall T
  #do something else
end

f(1, 2, 3)

Error message :

Index out of bounds
crystal/src/indexable.cr:0:17 in 'at'
crystal/src/indexable.cr:74:5 in '[]'
crystal/src/compiler/crystal/semantic/cover.cr:130:9 in 'mark_cover'
crystal/src/compiler/crystal/semantic/cover.cr:123:9 in 'mark_cover'
crystal/src/compiler/crystal/semantic/cover.cr:116:13 in 'mark_cover'
crystal/src/compiler/crystal/semantic/cover.cr:86:30 in 'compute_fast_cover'
crystal/src/compiler/crystal/semantic/cover.cr:21:7 in 'all?'
crystal/src/compiler/crystal/semantic/match.cr:134:91 in 'cover_all?'
crystal/src/compiler/crystal/semantic/method_lookup.cr:19:25 in 'lookup_matches'
crystal/src/compiler/crystal/semantic/method_lookup.cr:17:5 in 'lookup_matches'
crystal/src/compiler/crystal/semantic/call.cr:308:17 in 'lookup_matches_with_signature'
crystal/src/compiler/crystal/semantic/call.cr:293:28 in 'lookup_matches_checking_expansion'
crystal/src/compiler/crystal/semantic/call.cr:224:17 in 'lookup_matches_in_type'
crystal/src/compiler/crystal/semantic/call.cr:177:5 in 'lookup_matches_in'
crystal/src/compiler/crystal/semantic/call.cr:175:3 in 'lookup_matches_in'
crystal/src/compiler/crystal/semantic/call.cr:163:7 in 'lookup_matches_without_splat'
crystal/src/compiler/crystal/semantic/call.cr:101:7 in 'lookup_matches'
crystal/src/compiler/crystal/semantic/call.cr:68:5 in 'recalculate'
crystal/src/compiler/crystal/semantic/main_visitor.cr:1279:7 in 'visit'
crystal/src/compiler/crystal/syntax/visitor.cr:27:12 in 'accept'
crystal/src/compiler/crystal/syntax/ast.cr:150:27 in 'accept_children'
crystal/src/compiler/crystal/syntax/visitor.cr:28:11 in 'accept'
crystal/src/compiler/crystal/semantic/main_visitor.cr:7:7 in 'visit_main'
crystal/src/compiler/crystal/semantic/main_visitor.cr:5:5 in 'visit_main:process_finished_hooks:cleanup'
crystal/src/compiler/crystal/semantic.cr:22:7 in 'semantic'
crystal/src/compiler/crystal/compiler.cr:141:7 in 'compile'
crystal/src/compiler/crystal/command.cr:274:7 in 'compile'
crystal/src/compiler/crystal/command.cr:194:14 in 'run_command'
crystal/src/compiler/crystal/command.cr:105:11 in 'run'
crystal/src/compiler/crystal/command.cr:49:5 in 'run'
crystal/src/compiler/crystal/command.cr:48:3 in 'run'
crystal/src/compiler/crystal.cr:8:1 in '__crystal_main'
crystal/src/crystal/main.cr:12:3 in '_crystal_main'
crystal/src/crystal/main.cr:103:5 in 'main_user_code'
crystal/src/crystal/main.cr:91:7 in 'main'
crystal/src/crystal/main.cr:112:3 in 'main'
__libc_start_main
_start
???

crystal -v

Crystal 0.23.0+197 [2eca01b92] (2017-09-26)

LLVM: 3.9.1
Default target: x86_64-unknown-linux-gnu

[makenowjust]

Free variable is not related because this code reproduces the bug:

def foo(x, *y : *{Int32, Int32})
end

foo(1, 2, 3)

[oprypin]

I think it's simply that * makes no sense in a type restriction and should not be allowed.

def foo(x : *Int32)
end

foo(1)

Error in line 4: no overload matches 'foo' with type Int32
Overloads are:
 - foo(x : *Int32)

???

[oprypin]

Nevermind. It is actually a thing, just not in the context of the original post. It's supposed to be

def f(x, *y : T) forall T
  pp x, y
end

f(1, 2, 3)

[Sija]

@oprypin yep, it works if you omit first argument

def f(*args : *T) forall T
  pp args
end

f(1, 2, 3, :a, 'b', "c")

[makenowjust]

also my example without first argument works:

def foo(*x : *{Int32, Int32})
end

foo(1, 2)