`begin .. end` blocks in `ref` expression is unsupported

[Keluaa]

Defining arrays with a begin end block is valid:

julia> parsestmt(SyntaxNode, "[begin 1 end]")
SyntaxNode:
[vect]
  [block]
    1                                    :: Integer

Defining arrays with a type in front is valid:

julia> parsestmt(SyntaxNode, "Int[1]")
SyntaxNode:
[ref]
  Int                                    :: Identifier
  1                                      :: Integer

Yet we can't use both:

julia> parsestmt(SyntaxNode, "Int[begin 1 end]")
ERROR: ParseError:
# Error @ line 1:12
Int[begin 1 end]
#          └ ── Expected `]`
Stacktrace:
 [1] _parse(rule::Symbol, need_eof::Bool, ::Type{…}, text::String, index::Int64; version::VersionNumber, ignore_trivia::Bool, filename::Nothing, first_line::Int64, ignore_errors::Bool, ignore_warnings::Bool, kws::@Kwargs{})
   @ JuliaSyntax ~/.julia/dev/JuliaSyntax/src/parser_api.jl:98
 [2] _parse (repeats 2 times)
   @ ~/.julia/dev/JuliaSyntax/src/parser_api.jl:82 [inlined]
 [3] parsestmt(::Type{SyntaxNode}, text::String)
   @ JuliaSyntax ~/.julia/dev/JuliaSyntax/src/parser_api.jl:145
 [4] top-level scope
   @ REPL[5]:1

I expected something like this:

julia> parsestmt(SyntaxNode, "Int[begin 1 end]")
SyntaxNode:
[ref]
  Int                                    :: Identifier
  [block]
    1                                    :: Integer

Note that this AST is valid:

julia> eval(Expr(:ref, :Int, Expr(:block, LineNumberNode(1, :a), 1)))
1-element Vector{Int64}:
 1

[c42f]

The problem here is that typed array construction Int[begin] is syntactically entirely equivalent to array indexing a[begin] which eventually lowers to getindex(a, firstindex(a)). So when parsing this syntax we can't assume begin is a block.