Feature #14808: Last token of endless range should have EXPR_END

• Status: Rejected
• Assignee: -
• Target version: -

[aycabta (aycabta .)]

In 2.5.1:

irb(main):001:0> require 'ripper'
irb(main):002:0> pp Ripper.lex("case 5\nwhen 3..\n  puts(true)\nend\n")
[[[1, 0], :on_kw, "case", EXPR_BEG],
 [[1, 4], :on_sp, " ", EXPR_BEG],
 [[1, 5], :on_int, "5", EXPR_END|EXPR_ENDARG],
 [[1, 6], :on_nl, "\n", EXPR_BEG],
 [[2, 0], :on_kw, "when", EXPR_BEG],
 [[2, 4], :on_sp, " ", EXPR_BEG],
 [[2, 5], :on_int, "3", EXPR_END|EXPR_ENDARG],
 [[2, 6], :on_op, "..", EXPR_BEG],
 [[2, 8], :on_ignored_nl, "\n", EXPR_BEG],
 [[3, 0], :on_sp, "  ", EXPR_BEG],
 [[3, 2], :on_ident, "puts", EXPR_ARG],
 [[3, 6], :on_lparen, "(", EXPR_BEG|EXPR_LABEL],
 [[3, 7], :on_kw, "true", EXPR_END],
 [[3, 11], :on_rparen, ")", EXPR_ENDFN],
 [[3, 12], :on_nl, "\n", EXPR_BEG],
 [[4, 0], :on_kw, "end", EXPR_END],
 [[4, 3], :on_nl, "\n", EXPR_BEG]]

This is invalid code in 2.5.1, so I understand this result.

In 63451:

irb(main):001:0> require 'ripper'
irb(main):002:0> pp Ripper.lex("case 5\nwhen 3..\n  puts(true)\nend\n")
[[[1, 0], :on_kw, "case", EXPR_BEG],
 [[1, 4], :on_sp, " ", EXPR_BEG],
 [[1, 5], :on_int, "5", EXPR_END],
 [[1, 6], :on_nl, "\n", EXPR_BEG],
 [[2, 0], :on_kw, "when", EXPR_BEG],
 [[2, 4], :on_sp, " ", EXPR_BEG],
 [[2, 5], :on_int, "3", EXPR_END],
 [[2, 6], :on_op, "..", EXPR_BEG],
 [[2, 8], :on_ignored_nl, "\n", EXPR_BEG],
 [[3, 0], :on_sp, "  ", EXPR_BEG],
 [[3, 2], :on_ident, "puts", EXPR_ARG],
 [[3, 6], :on_lparen, "(", EXPR_BEG|EXPR_LABEL],
 [[3, 7], :on_kw, "true", EXPR_END],
 [[3, 11], :on_rparen, ")", EXPR_ENDFN],
 [[3, 12], :on_nl, "\n", EXPR_BEG],
 [[4, 0], :on_kw, "end", EXPR_END],
 [[4, 3], :on_nl, "\n", EXPR_BEG]]

This is correct code in this revision.

I think that lex_state of the last token of endless range, [[2, 6], :on_op, "..", EXPR_BEG], it should be EXPR_END. Because it's the end of an argument. It's important for REPL, RDoc, and so on.

But lex_state is parser matter in parse.y. How about this for the parser of Ruby compiler?

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Rejected

That code is valid syntax in both versions, and it is not an endless range in the trunk as well as 2.5.
As .. is an infix operator and requires the RHS, newlines following it are just ignored.
So it equals to:

case 5
when (3..puts(true))
end

It results in an error at runtime in 2.5, not a syntax error.

$ ruby2.5 -rripper -e 'case 5' -e 'when 3..' -e  'puts(true)' -e end
true
Traceback (most recent call last):
-e:3:in `<main>': bad value for range (ArgumentError)

To put an endless range there, use parentheses.

[aycabta (aycabta .)]

• Related to Bug #14824: Endless Range Support in irb added