@ ProgramNode (location: (1,0)-(33,14))
├── locals: [:foo, :ab]
└── statements:
    @ StatementsNode (location: (1,0)-(33,14))
    └── body: (length: 16)
        ├── @ CallNode (location: (1,0)-(1,9))
        │   ├── receiver: ∅
        │   ├── call_operator_loc: ∅
        │   ├── message_loc: (1,0)-(1,3) = "foo"
        │   ├── opening_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (1,4)-(1,9))
        │   │   ├── arguments: (length: 1)
        │   │   │   └── @ RegularExpressionNode (location: (1,4)-(1,9))
        │   │   │       ├── opening_loc: (1,4)-(1,5) = "/"
        │   │   │       ├── content_loc: (1,5)-(1,8) = "bar"
        │   │   │       ├── closing_loc: (1,8)-(1,9) = "/"
        │   │   │       ├── unescaped: "bar"
        │   │   │       └── flags: ∅
        │   │   └── flags: ∅
        │   ├── closing_loc: ∅
        │   ├── block: ∅
        │   ├── flags: ∅
        │   └── name: :foo
        ├── @ RegularExpressionNode (location: (3,0)-(3,8))
        │   ├── opening_loc: (3,0)-(3,3) = "%r{"
        │   ├── content_loc: (3,3)-(3,6) = "abc"
        │   ├── closing_loc: (3,6)-(3,8) = "}i"
        │   ├── unescaped: "abc"
        │   └── flags: ignore_case
        ├── @ RegularExpressionNode (location: (5,0)-(5,5))
        │   ├── opening_loc: (5,0)-(5,1) = "/"
        │   ├── content_loc: (5,1)-(5,4) = "a\\b"
        │   ├── closing_loc: (5,4)-(5,5) = "/"
        │   ├── unescaped: "a\\b"
        │   └── flags: ∅
        ├── @ InterpolatedRegularExpressionNode (location: (7,0)-(7,11))
        │   ├── opening_loc: (7,0)-(7,1) = "/"
        │   ├── parts: (length: 2)
        │   │   ├── @ StringNode (location: (7,1)-(7,5))
        │   │   │   ├── flags: ∅
        │   │   │   ├── opening_loc: ∅
        │   │   │   ├── content_loc: (7,1)-(7,5) = "aaa "
        │   │   │   ├── closing_loc: ∅
        │   │   │   └── unescaped: "aaa "
        │   │   └── @ EmbeddedVariableNode (location: (7,5)-(7,10))
        │   │       ├── operator_loc: (7,5)-(7,6) = "#"
        │   │       └── variable:
        │   │           @ GlobalVariableReadNode (location: (7,6)-(7,10))
        │   │           └── name: :$bbb
        │   ├── closing_loc: (7,10)-(7,11) = "/"
        │   └── flags: ∅
        ├── @ InterpolatedRegularExpressionNode (location: (9,0)-(9,16))
        │   ├── opening_loc: (9,0)-(9,1) = "/"
        │   ├── parts: (length: 3)
        │   │   ├── @ StringNode (location: (9,1)-(9,5))
        │   │   │   ├── flags: ∅
        │   │   │   ├── opening_loc: ∅
        │   │   │   ├── content_loc: (9,1)-(9,5) = "aaa "
        │   │   │   ├── closing_loc: ∅
        │   │   │   └── unescaped: "aaa "
        │   │   ├── @ EmbeddedStatementsNode (location: (9,5)-(9,11))
        │   │   │   ├── opening_loc: (9,5)-(9,7) = "\#{"
        │   │   │   ├── statements:
        │   │   │   │   @ StatementsNode (location: (9,7)-(9,10))
        │   │   │   │   └── body: (length: 1)
        │   │   │   │       └── @ CallNode (location: (9,7)-(9,10))
        │   │   │   │           ├── receiver: ∅
        │   │   │   │           ├── call_operator_loc: ∅
        │   │   │   │           ├── message_loc: (9,7)-(9,10) = "bbb"
        │   │   │   │           ├── opening_loc: ∅
        │   │   │   │           ├── arguments: ∅
        │   │   │   │           ├── closing_loc: ∅
        │   │   │   │           ├── block: ∅
        │   │   │   │           ├── flags: variable_call
        │   │   │   │           └── name: :bbb
        │   │   │   └── closing_loc: (9,10)-(9,11) = "}"
        │   │   └── @ StringNode (location: (9,11)-(9,15))
        │   │       ├── flags: ∅
        │   │       ├── opening_loc: ∅
        │   │       ├── content_loc: (9,11)-(9,15) = " ccc"
        │   │       ├── closing_loc: ∅
        │   │       └── unescaped: " ccc"
        │   ├── closing_loc: (9,15)-(9,16) = "/"
        │   └── flags: ∅
        ├── @ ArrayNode (location: (11,0)-(11,27))
        │   ├── elements: (length: 2)
        │   │   ├── @ MatchWriteNode (location: (11,1)-(11,21))
        │   │   │   ├── call:
        │   │   │   │   @ CallNode (location: (11,1)-(11,21))
        │   │   │   │   ├── receiver:
        │   │   │   │   │   @ RegularExpressionNode (location: (11,1)-(11,14))
        │   │   │   │   │   ├── opening_loc: (11,1)-(11,2) = "/"
        │   │   │   │   │   ├── content_loc: (11,2)-(11,13) = "(?<foo>bar)"
        │   │   │   │   │   ├── closing_loc: (11,13)-(11,14) = "/"
        │   │   │   │   │   ├── unescaped: "(?<foo>bar)"
        │   │   │   │   │   └── flags: ∅
        │   │   │   │   ├── call_operator_loc: ∅
        │   │   │   │   ├── message_loc: (11,15)-(11,17) = "=~"
        │   │   │   │   ├── opening_loc: ∅
        │   │   │   │   ├── arguments:
        │   │   │   │   │   @ ArgumentsNode (location: (11,18)-(11,21))
        │   │   │   │   │   ├── arguments: (length: 1)
        │   │   │   │   │   │   └── @ CallNode (location: (11,18)-(11,21))
        │   │   │   │   │   │       ├── receiver: ∅
        │   │   │   │   │   │       ├── call_operator_loc: ∅
        │   │   │   │   │   │       ├── message_loc: (11,18)-(11,21) = "baz"
        │   │   │   │   │   │       ├── opening_loc: ∅
        │   │   │   │   │   │       ├── arguments: ∅
        │   │   │   │   │   │       ├── closing_loc: ∅
        │   │   │   │   │   │       ├── block: ∅
        │   │   │   │   │   │       ├── flags: variable_call
        │   │   │   │   │   │       └── name: :baz
        │   │   │   │   │   └── flags: ∅
        │   │   │   │   ├── closing_loc: ∅
        │   │   │   │   ├── block: ∅
        │   │   │   │   ├── flags: ∅
        │   │   │   │   └── name: :=~
        │   │   │   └── locals: [:foo]
        │   │   └── @ LocalVariableReadNode (location: (11,23)-(11,26))
        │   │       ├── name: :foo
        │   │       └── depth: 0
        │   ├── opening_loc: (11,0)-(11,1) = "["
        │   └── closing_loc: (11,26)-(11,27) = "]"
        ├── @ RegularExpressionNode (location: (13,0)-(13,6))
        │   ├── opening_loc: (13,0)-(13,1) = "/"
        │   ├── content_loc: (13,1)-(13,4) = "abc"
        │   ├── closing_loc: (13,4)-(13,6) = "/i"
        │   ├── unescaped: "abc"
        │   └── flags: ignore_case
        ├── @ RegularExpressionNode (location: (15,0)-(15,26))
        │   ├── opening_loc: (15,0)-(15,3) = "%r/"
        │   ├── content_loc: (15,3)-(15,24) = "[a-z$._?][\\w$.?\#@~]*:"
        │   ├── closing_loc: (15,24)-(15,26) = "/i"
        │   ├── unescaped: "[a-z$._?][\\w$.?\#@~]*:"
        │   └── flags: ignore_case
        ├── @ RegularExpressionNode (location: (17,0)-(17,37))
        │   ├── opening_loc: (17,0)-(17,3) = "%r/"
        │   ├── content_loc: (17,3)-(17,35) = "([a-z$._?][\\w$.?\#@~]*)(\\s+)(equ)"
        │   ├── closing_loc: (17,35)-(17,37) = "/i"
        │   ├── unescaped: "([a-z$._?][\\w$.?\#@~]*)(\\s+)(equ)"
        │   └── flags: ignore_case
        ├── @ RegularExpressionNode (location: (19,0)-(19,25))
        │   ├── opening_loc: (19,0)-(19,3) = "%r/"
        │   ├── content_loc: (19,3)-(19,23) = "[a-z$._?][\\w$.?\#@~]*"
        │   ├── closing_loc: (19,23)-(19,25) = "/i"
        │   ├── unescaped: "[a-z$._?][\\w$.?\#@~]*"
        │   └── flags: ignore_case
        ├── @ RegularExpressionNode (location: (21,0)-(24,1))
        │   ├── opening_loc: (21,0)-(21,3) = "%r("
        │   ├── content_loc: (21,3)-(23,0) = "\n(?:[\\w\#$%_']|\\(\\)|\\(,\\)|\\[\\]|[0-9])*\n  (?:[\\w\#$%_']+)\n"
        │   ├── closing_loc: (24,0)-(24,1) = ")"
        │   ├── unescaped: "\n(?:[\\w\#$%_']|\\(\\)|\\(,\\)|\\[\\]|[0-9])*\n  (?:[\\w\#$%_']+)\n"
        │   └── flags: ∅
        ├── @ CallNode (location: (26,0)-(26,16))
        │   ├── receiver:
        │   │   @ RegularExpressionNode (location: (26,0)-(26,8))
        │   │   ├── opening_loc: (26,0)-(26,1) = "/"
        │   │   ├── content_loc: (26,1)-(26,7) = "(?#\\))"
        │   │   ├── closing_loc: (26,7)-(26,8) = "/"
        │   │   ├── unescaped: "(?#\\))"
        │   │   └── flags: ∅
        │   ├── call_operator_loc: ∅
        │   ├── message_loc: (26,9)-(26,11) = "=~"
        │   ├── opening_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (26,12)-(26,16))
        │   │   ├── arguments: (length: 1)
        │   │   │   └── @ StringNode (location: (26,12)-(26,16))
        │   │   │       ├── flags: ∅
        │   │   │       ├── opening_loc: (26,12)-(26,13) = "\""
        │   │   │       ├── content_loc: (26,13)-(26,15) = "hi"
        │   │   │       ├── closing_loc: (26,15)-(26,16) = "\""
        │   │   │       └── unescaped: "hi"
        │   │   └── flags: ∅
        │   ├── closing_loc: ∅
        │   ├── block: ∅
        │   ├── flags: ∅
        │   └── name: :=~
        ├── @ RegularExpressionNode (location: (28,0)-(28,9))
        │   ├── opening_loc: (28,0)-(28,3) = "%r#"
        │   ├── content_loc: (28,3)-(28,8) = "pound"
        │   ├── closing_loc: (28,8)-(28,9) = "#"
        │   ├── unescaped: "pound"
        │   └── flags: ∅
        ├── @ InterpolatedRegularExpressionNode (location: (30,0)-(30,13))
        │   ├── opening_loc: (30,0)-(30,1) = "/"
        │   ├── parts: (length: 2)
        │   │   ├── @ StringNode (location: (30,1)-(30,5))
        │   │   │   ├── flags: ∅
        │   │   │   ├── opening_loc: ∅
        │   │   │   ├── content_loc: (30,1)-(30,5) = "aaa "
        │   │   │   ├── closing_loc: ∅
        │   │   │   └── unescaped: "aaa "
        │   │   └── @ EmbeddedStatementsNode (location: (30,5)-(30,11))
        │   │       ├── opening_loc: (30,5)-(30,7) = "\#{"
        │   │       ├── statements:
        │   │       │   @ StatementsNode (location: (30,7)-(30,10))
        │   │       │   └── body: (length: 1)
        │   │       │       └── @ CallNode (location: (30,7)-(30,10))
        │   │       │           ├── receiver: ∅
        │   │       │           ├── call_operator_loc: ∅
        │   │       │           ├── message_loc: (30,7)-(30,10) = "bbb"
        │   │       │           ├── opening_loc: ∅
        │   │       │           ├── arguments: ∅
        │   │       │           ├── closing_loc: ∅
        │   │       │           ├── block: ∅
        │   │       │           ├── flags: variable_call
        │   │       │           └── name: :bbb
        │   │       └── closing_loc: (30,10)-(30,11) = "}"
        │   ├── closing_loc: (30,11)-(30,13) = "/o"
        │   └── flags: once
        ├── @ MatchWriteNode (location: (32,0)-(33,10))
        │   ├── call:
        │   │   @ CallNode (location: (32,0)-(33,10))
        │   │   ├── receiver:
        │   │   │   @ RegularExpressionNode (location: (32,0)-(33,4))
        │   │   │   ├── opening_loc: (32,0)-(32,1) = "/"
        │   │   │   ├── content_loc: (32,1)-(33,3) = "(?<a\\\nb>)"
        │   │   │   ├── closing_loc: (33,3)-(33,4) = "/"
        │   │   │   ├── unescaped: "(?<ab>)"
        │   │   │   └── flags: ∅
        │   │   ├── call_operator_loc: ∅
        │   │   ├── message_loc: (33,5)-(33,7) = "=~"
        │   │   ├── opening_loc: ∅
        │   │   ├── arguments:
        │   │   │   @ ArgumentsNode (location: (33,8)-(33,10))
        │   │   │   ├── arguments: (length: 1)
        │   │   │   │   └── @ StringNode (location: (33,8)-(33,10))
        │   │   │   │       ├── flags: ∅
        │   │   │   │       ├── opening_loc: (33,8)-(33,9) = "\""
        │   │   │   │       ├── content_loc: (33,9)-(33,9) = ""
        │   │   │   │       ├── closing_loc: (33,9)-(33,10) = "\""
        │   │   │   │       └── unescaped: ""
        │   │   │   └── flags: ∅
        │   │   ├── closing_loc: ∅
        │   │   ├── block: ∅
        │   │   ├── flags: ∅
        │   │   └── name: :=~
        │   └── locals: [:ab]
        └── @ LocalVariableReadNode (location: (33,12)-(33,14))
            ├── name: :ab
            └── depth: 0