[Parser] Issues with BoolOp node generation in new parser

[akshanshbhatt]

❯ cat examples/expr2.py
a or b or c or d

❯ lpy --show-ast examples/expr2.py --tree  # Existing Parser
└-Module
  |-body=↧
  | └-Expr
  |   └-value=BoolOp
  |     |-boolopType=Or
  |     └-values=↧
  |       |-Name
  |       | |-id=a
  |       | └-expr_contextType=Load
  |       |-Name
  |       | |-id=b
  |       | └-expr_contextType=Load
  |       |-Name
  |       | |-id=c
  |       | └-expr_contextType=Load
  |       └-Name
  |         |-id=d
  |         └-expr_contextType=Load
  └-type_ignores=↧

❯ lpy --show-ast --new-parser examples/expr2.py --tree  # New Parser
└-Module
  |-body=↧
  | └-Expr
  |   └-value=BoolOp
  |     |-boolopType=Or
  |     └-values=↧
  |       |-BoolOp
  |       | |-boolopType=Or
  |       | └-values=↧
  |       |   |-BoolOp
  |       |   | |-boolopType=Or
  |       |   | └-values=↧
  |       |   |   |-Name
  |       |   |   | |-id=a
  |       |   |   | └-expr_contextType=Load
  |       |   |   └-Name
  |       |   |     |-id=b
  |       |   |     └-expr_contextType=Load
  |       |   └-Name
  |       |     |-id=c
  |       |     └-expr_contextType=Load
  |       └-Name
  |         |-id=d
  |         └-expr_contextType=Load
  └-type_ignores=↧

The new parser currently only supports BoolOp node generation with two operands (like BinOp). If an expression contains multiple and or or, the parser keeps creating new BoolOp nodes instead of retaining them in a single node with multiple expr values.

[akshanshbhatt]

Some other examples that should work -

a or (b or c) or d
a or ((b or c) or d) or e
a and b and c or d and e and f or g and h and i

We can add them as tests.

[Thirumalai-Shaktivel]

Some issues are fixed in #773. The only left out part is:

(a or b) or c

The problem here is that, as parenthesis information is not used or stored by the macros, it is difficult to handle the above example:
OLD Parser AST:

$ lpython --show-ast examples/expr2.py --tree
└-Module
  |-body=↧
  | └-Expr
  |   └-value=BoolOp
  |     |-boolopType=Or
  |     └-values=↧
  |       |-BoolOp
  |       | |-boolopType=Or
  |       | └-values=↧
  |       |   |-Name
  |       |   | |-id=a
  |       |   | └-expr_contextType=Load
  |       |   └-Name
  |       |     |-id=b
  |       |     └-expr_contextType=Load
  |       └-Name
  |         |-id=c
  |         └-expr_contextType=Load
  └-type_ignores=↧

NEW Parser AST (this PR):

$ lpython --show-ast examples/expr2.py --tree --new-parser
└-Module
  |-body=↧
  | └-Expr
  |   └-value=BoolOp
  |     |-boolopType=Or
  |     └-values=↧
  |       |-Name
  |       | |-id=a
  |       | └-expr_contextType=Load
  |       |-Name
  |       | |-id=b
  |       | └-expr_contextType=Load
  |       └-Name
  |         |-id=c
  |         └-expr_contextType=Load
  └-type_ignores=↧

[Thirumalai-Shaktivel]

Closing in favour of #848.