YARP accepts command method call in many places where Ruby rejects. #1575

tompng · 2023-09-21T13:08:35Z

code = <<RUBY
[a b]
{a: b c}
...a b
if ...a b; end
a b, c d
a(b, c d)
a(*b c)
a(**b c)
a(&b c)
+a b
a + b c
a && b c
a =~ b c
a = b, c d
a = *b c
a ? b c : d e
defined? a b
def f a = b c; end
def f(a = b c); end
->a=b c{}
->(a=b c){}
case; when a b; end
begin; rescue a b; end
RUBY
code.lines.map{YARP.parse(_1).success?}.uniq #=> [true]
code.lines.map{system('ruby', '-ce', _1)}.uniq #=> [false]

Fix ruby#1468 Fix ruby#1575 To decide command-style method calls are allowed, this introduce a new parameter `accepts_command_call` to `parse_expression` and some functions. Although one think this can be solved by operator precedence, it is hard or impossible, because the precedence of command-style calls is skewed (e.g. `! bar 1 ` is accepted, but `foo = ! bar 1` is rejected.) One of the most complex examples is that: (1) even though `foo = bar = baz 1` and `foo, bar = baz 1` is accepted, (2) `foo, bar = baz = fuzz 1` is rejected. To implement this behavior, this introduces a new binding power `PM_BINDING_POWER_MULTI_ASSIGNMENT` and uses it for distinguish which single assignments or multi assignments at their RHS.

Fix ruby/prism#1468 Fix ruby/prism#1575 To decide command-style method calls are allowed, this introduce a new parameter `accepts_command_call` to `parse_expression` and some functions. Although one think this can be solved by operator precedence, it is hard or impossible, because the precedence of command-style calls is skewed (e.g. `! bar 1 ` is accepted, but `foo = ! bar 1` is rejected.) One of the most complex examples is that: (1) even though `foo = bar = baz 1` and `foo, bar = baz 1` is accepted, (2) `foo, bar = baz = fuzz 1` is rejected. To implement this behavior, this introduces a new binding power `PM_BINDING_POWER_MULTI_ASSIGNMENT` and uses it for distinguish which single assignments or multi assignments at their RHS. ruby/prism@d4dd49ca81

kddnewton added bug Something isn't working invalid-syntax labels Sep 21, 2023

makenowjust mentioned this issue Nov 30, 2023

Fix to parse command-style method calls more correctly #1949

Merged

kddnewton closed this as completed in #1949 Dec 5, 2023

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YARP accepts command method call in many places where Ruby rejects. #1575

YARP accepts command method call in many places where Ruby rejects. #1575

tompng commented Sep 21, 2023 •

edited

YARP accepts command method call in many places where Ruby rejects. #1575

YARP accepts command method call in many places where Ruby rejects. #1575

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tompng commented Sep 21, 2023 • edited

tompng commented Sep 21, 2023 •

edited