LTA error message "Undeclared routine" rather than "Two terms in a row" from dropped comma on say hash

[doomvox]

The Problem

Given a simple hash:

my %h = A => 1;

If you're trying to type:

say "output: ", %h<A>;

But drop the comma separator, you get an "Undeclared routine" error:

 say "output: " %h<A>;
 # Undeclared routine:
 #     h used at line 16. Did you mean 'HOW'?

Rather than the expected "Two terms in a row", which
you'll see if you do something similar with an array:

    my @a = < A B C >;  
    say "output: " @a[1];
    # Two terms in a row

Environment

• Operating system:

  Debian 5.10.209-2 (2024-01-31) x86_64 GNU/Linux

• Compiler version (rakudo -v or raku -v):

  raku --version
  Welcome to Rakudo™ v2023.02.
  Implementing the Raku® Programming Language v6.d.
  Built on MoarVM version 2023.02.

[jnthn]

The difference is because % is an operator (modulo), and so an infix is found, and the next term is also syntactically well-formed (listop function syntax for h and indexing its result). Since a function may be post-declared, then an error is only produced once parsing is done and no h was found.