In this commit we're splitting up the call nodes that were in target
positions (that is, for loop indices, rescue error captures, and
multi assign targets).
Previously, we would simply leave the call nodes in place. This had
the benefit of keeping the AST relatively simple, but had the
downside of not being very explicit. If a static analysis tool wanted
to only look at call nodes, it could easily be confused because the
method would have 1 fewer argument than it would actually be called
with.
This also brings some consistency to the AST. All of the nodes in
a target position are now *TargetNode nodes. These should all be
treated the same, and the call nodes can now be treated the same.
Finally, there is benefit to memory. Because being in a target
position ensures we don't have some fields, we can strip down the
number of fields on these nodes.
So this commit introduces two new nodes: CallTargetNode and
IndexTargetNode. For CallTargetNode we get to drop the opening_loc,
closing_loc, arguments, and block. Those can never be present. We
also get to mark their fields as non-null, so they will always be
seen as present.
The IndexTargetNode keeps around most of its fields but gets to
drop both the name (because it will always be []=) and the
message_loc (which was always super confusing because it included
the arguments by virtue of being inside the []).
Overall, this adds complexity to the AST at the expense of memory
savings and explicitness. I believe this tradeoff is worth it in
this case, especially because these are very much not common nodes
in the first place.
3ef71cdb45
The locals_body_index gives the index in the locals array where
the locals from the body start. This allows compilers to easily
index past the parameters in the locals array.
5d4627b890
It's possible to write the following and have it be valid Ruby:
```
defined?("foo"
)
```
But Prism wasn't taking the new line into account. This adds an
`accept1` for a `PM_TOKEN_NEWLINE` to account for this. I've also
updated the fixtures and snapshots to test this.
b87f8eedc6
Fix https://github.com/ruby/prism/pull/1468
Fix https://github.com/ruby/prism/pull/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.
d4dd49ca81
Previously numbered parameters were a field on blocks and lambdas
that indicated the maximum number of numbered parameters in either
the block or lambda, respectively. However they also had a
parameters field that would always be nil in these cases.
This changes it so that we introduce a NumberedParametersNode that
goes in place of parameters, which has a single uint8_t maximum
field on it. That field contains the maximum numbered parameter in
either the block or lambda.
As a part of the PR, I'm introducing a new UInt8Field type that
can be used on nodes, which is just to make it a little more
explicit what the maximum values can be (the maximum is actually 9,
since it only goes up to _9). Plus we can do a couple of nice
things in serialization like just read a single byte.
2d87303903
Fix https://github.com/ruby/prism/pull/1946
This fixes to set an error position for unterminated strings to the
opening delimiters. Previously, the error position was set to the end
of the delimiter.
The same fix applies to other string-like literals.
Additionally, this fixes https://github.com/ruby/prism/pull/1946; that is, it adds the last part of the
string even though the string literal does not terminate.
c1240baafd
Ruby allows for 0 or negative line start, this is often used
with `eval` calls to get a correct offset when prefixing a snippet.
e.g.
```ruby
caller = caller_locations(1, 1).first
class_eval <<~RUBY, caller.path, caller.line - 2
# frozen_string_literal: true
def some_method
#{caller_provided_code_snippet}
end
RUBY
```
0d14ed1452
