Bug #22183: parse.y interpolation inside lambda literal

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 3.3: REQUIRED, 3.4: REQUIRED, 4.0: REQUIRED

[kddnewton (Kevin Newton)]

This is an odd bug that I think is just leaking parse.y internals to do with paren_nest and lambda_beginning_p.

In parse.y, p->lex.lpar_beg is not isolated when the lexer enters a string interpolation (tSTRING_DBEG). So lambda_beginning_p() can be true inside an interpolation that appears between a lambda's -> and its body, causing a do or { inside the interpolation to be lexed as keyword_do_LAMBDA / tLAMBEG and produce a syntax error.

-> a = "#{foo do end}" do end

$ ruby --parser=parse.y -c test.rb
test.rb: test.rb:1: syntax error found (SyntaxError)
> 1 | -> a = "#{foo do end}" do end
    |               ^~ unexpected 'do' for lambda, ...

The same applies with a brace block inside the interpolation:

-> a = "#{foo { }}" do end   # parse.y: syntax error at the `{`, lexed as tLAMBEG

I'm not 100% sure about this one to be honest. I guess it could potentially have been a design decision? But it seems inconsistent:

-> a = ("#{foo do end}") do end   # parse.y: OK
-> a = "#{foo do end}" do end     # parse.y: syntax error

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|3f7d4bc859f03f4c7ea131af910d1c4ae142586d.

---

[Bug #22183] Preserve lpar_beg across interpolation

Fix unexpected keyword_do_LAMBDA inside string interpolation within
default argument of lambda.

[nobu (Nobuyoshi Nakada)]

• Backport changed from 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN to 3.3: REQUIRED, 3.4: REQUIRED, 4.0: REQUIRED