[ruby/yarp] Introduce MatchWriteNode

This rarely used node holds information about the local variables
that need to get written in the case a regular expression is used on
the left-hand side of a =~ operator and it has named capture groups.

Note that we already "handled" these nodes by adding locals to the
AST, but we didn't actually expose this information, making it
difficult to compile.

The general idea behind this node is that it maintains the ability
for consumers to find all of the call nodes in the tree easily so
it's not flattening down. However, it should be okay because you
hopefully don't need any information in the call node to determine
what to compile because the locals list is on the top level.

https://github.com/ruby/yarp/commit/e136e7f9a8

2 files changed, 58 insertions, 52 deletions

diff --git a/test/yarp/snapshots/regex.txt b/test/yarp/snapshots/regex.txt
index f474669ee0..6f0d42ce3f 100644
--- a/test/yarp/snapshots/regex.txt
+++ b/test/yarp/snapshots/regex.txt
@@ -84,34 +84,37 @@
         │   └── flags: ∅
         ├── @ ArrayNode (location: (59...86))
         │   ├── elements: (length: 2)
-        │   │   ├── @ CallNode (location: (60...80))
-        │   │   │   ├── receiver:
-        │   │   │   │   @ RegularExpressionNode (location: (60...73))
-        │   │   │   │   ├── opening_loc: (60...61) = "/"
-        │   │   │   │   ├── content_loc: (61...72) = "(?<foo>bar)"
-        │   │   │   │   ├── closing_loc: (72...73) = "/"
-        │   │   │   │   ├── unescaped: "(?<foo>bar)"
-        │   │   │   │   └── flags: ∅
-        │   │   │   ├── call_operator_loc: ∅
-        │   │   │   ├── message_loc: (74...76) = "=~"
-        │   │   │   ├── opening_loc: ∅
-        │   │   │   ├── arguments:
-        │   │   │   │   @ ArgumentsNode (location: (77...80))
-        │   │   │   │   └── arguments: (length: 1)
-        │   │   │   │       └── @ CallNode (location: (77...80))
-        │   │   │   │           ├── receiver: ∅
-        │   │   │   │           ├── call_operator_loc: ∅
-        │   │   │   │           ├── message_loc: (77...80) = "baz"
-        │   │   │   │           ├── opening_loc: ∅
-        │   │   │   │           ├── arguments: ∅
-        │   │   │   │           ├── closing_loc: ∅
-        │   │   │   │           ├── block: ∅
-        │   │   │   │           ├── flags: variable_call
-        │   │   │   │           └── name: "baz"
-        │   │   │   ├── closing_loc: ∅
-        │   │   │   ├── block: ∅
-        │   │   │   ├── flags: ∅
-        │   │   │   └── name: "=~"
+        │   │   ├── @ MatchWriteNode (location: (60...80))
+        │   │   │   ├── call:
+        │   │   │   │   @ CallNode (location: (60...80))
+        │   │   │   │   ├── receiver:
+        │   │   │   │   │   @ RegularExpressionNode (location: (60...73))
+        │   │   │   │   │   ├── opening_loc: (60...61) = "/"
+        │   │   │   │   │   ├── content_loc: (61...72) = "(?<foo>bar)"
+        │   │   │   │   │   ├── closing_loc: (72...73) = "/"
+        │   │   │   │   │   ├── unescaped: "(?<foo>bar)"
+        │   │   │   │   │   └── flags: ∅
+        │   │   │   │   ├── call_operator_loc: ∅
+        │   │   │   │   ├── message_loc: (74...76) = "=~"
+        │   │   │   │   ├── opening_loc: ∅
+        │   │   │   │   ├── arguments:
+        │   │   │   │   │   @ ArgumentsNode (location: (77...80))
+        │   │   │   │   │   └── arguments: (length: 1)
+        │   │   │   │   │       └── @ CallNode (location: (77...80))
+        │   │   │   │   │           ├── receiver: ∅
+        │   │   │   │   │           ├── call_operator_loc: ∅
+        │   │   │   │   │           ├── message_loc: (77...80) = "baz"
+        │   │   │   │   │           ├── opening_loc: ∅
+        │   │   │   │   │           ├── arguments: ∅
+        │   │   │   │   │           ├── closing_loc: ∅
+        │   │   │   │   │           ├── block: ∅
+        │   │   │   │   │           ├── flags: variable_call
+        │   │   │   │   │           └── name: "baz"
+        │   │   │   │   ├── closing_loc: ∅
+        │   │   │   │   ├── block: ∅
+        │   │   │   │   ├── flags: ∅
+        │   │   │   │   └── name: "=~"
+        │   │   │   └── locals: [:foo]
         │   │   └── @ LocalVariableReadNode (location: (82...85))
         │   │       ├── name: :foo
         │   │       └── depth: 0
diff --git a/test/yarp/snapshots/whitequark/lvar_injecting_match.txt b/test/yarp/snapshots/whitequark/lvar_injecting_match.txt
index 2375854350..e570bf18a8 100644
--- a/test/yarp/snapshots/whitequark/lvar_injecting_match.txt
+++ b/test/yarp/snapshots/whitequark/lvar_injecting_match.txt
@@ -3,30 +3,33 @@
 └── statements:
     @ StatementsNode (location: (0...31))
     └── body: (length: 2)
-        ├── @ CallNode (location: (0...24))
-        │   ├── receiver:
-        │   │   @ RegularExpressionNode (location: (0...15))
-        │   │   ├── opening_loc: (0...1) = "/"
-        │   │   ├── content_loc: (1...14) = "(?<match>bar)"
-        │   │   ├── closing_loc: (14...15) = "/"
-        │   │   ├── unescaped: "(?<match>bar)"
-        │   │   └── flags: ∅
-        │   ├── call_operator_loc: ∅
-        │   ├── message_loc: (16...18) = "=~"
-        │   ├── opening_loc: ∅
-        │   ├── arguments:
-        │   │   @ ArgumentsNode (location: (19...24))
-        │   │   └── arguments: (length: 1)
-        │   │       └── @ StringNode (location: (19...24))
-        │   │           ├── flags: ∅
-        │   │           ├── opening_loc: (19...20) = "'"
-        │   │           ├── content_loc: (20...23) = "bar"
-        │   │           ├── closing_loc: (23...24) = "'"
-        │   │           └── unescaped: "bar"
-        │   ├── closing_loc: ∅
-        │   ├── block: ∅
-        │   ├── flags: ∅
-        │   └── name: "=~"
+        ├── @ MatchWriteNode (location: (0...24))
+        │   ├── call:
+        │   │   @ CallNode (location: (0...24))
+        │   │   ├── receiver:
+        │   │   │   @ RegularExpressionNode (location: (0...15))
+        │   │   │   ├── opening_loc: (0...1) = "/"
+        │   │   │   ├── content_loc: (1...14) = "(?<match>bar)"
+        │   │   │   ├── closing_loc: (14...15) = "/"
+        │   │   │   ├── unescaped: "(?<match>bar)"
+        │   │   │   └── flags: ∅
+        │   │   ├── call_operator_loc: ∅
+        │   │   ├── message_loc: (16...18) = "=~"
+        │   │   ├── opening_loc: ∅
+        │   │   ├── arguments:
+        │   │   │   @ ArgumentsNode (location: (19...24))
+        │   │   │   └── arguments: (length: 1)
+        │   │   │       └── @ StringNode (location: (19...24))
+        │   │   │           ├── flags: ∅
+        │   │   │           ├── opening_loc: (19...20) = "'"
+        │   │   │           ├── content_loc: (20...23) = "bar"
+        │   │   │           ├── closing_loc: (23...24) = "'"
+        │   │   │           └── unescaped: "bar"
+        │   │   ├── closing_loc: ∅
+        │   │   ├── block: ∅
+        │   │   ├── flags: ∅
+        │   │   └── name: "=~"
+        │   └── locals: [:match]
         └── @ LocalVariableReadNode (location: (26...31))
             ├── name: :match
             └── depth: 0