Misc #20035: Command-line settings move from parser to compiler

• Status: Closed
• Assignee: -

[kddnewton (Kevin Newton)]

Right now, when you pass -n, -p, -l, or -a, these options are all passed to the parser to manipulate the parse tree into giving you the desired behavior. For example:

$ ruby --dump=parsetree -p -e "foo"

###########################################################
## Do NOT use this node dump for any purpose other than  ##
## debug and research.  Compatibility is not guaranteed. ##
###########################################################

# @ NODE_SCOPE (id: 1, line: 1, location: (1,0)-(1,3))
# +- nd_tbl: (empty)
# +- nd_args:
# |   (null node)
# +- nd_body:
#     @ NODE_WHILE (id: 10, line: 1, location: (1,0)-(1,0))
#     +- nd_state: 1 (while-end)
#     +- nd_cond:
#     |   @ NODE_FCALL (id: 9, line: 1, location: (1,0)-(1,0))
#     |   +- nd_mid: :gets
#     |   +- nd_args:
#     |       @ NODE_LIST (id: 8, line: 1, location: (1,0)-(1,0))
#     |       +- nd_alen: 1
#     |       +- nd_head:
#     |       |   @ NODE_GVAR (id: 7, line: 1, location: (1,0)-(1,0))
#     |       |   +- nd_entry: :$/
#     |       +- nd_next:
#     |           (null node)
#     +- nd_body:
#         @ NODE_BLOCK (id: 5, line: 1, location: (1,0)-(1,0))
#         +- nd_head (1):
#         |   @ NODE_VCALL (id: 0, line: 1, location: (1,0)-(1,3))*
#         |   +- nd_mid: :foo
#         +- nd_head (2):
#             @ NODE_FCALL (id: 4, line: 1, location: (1,0)-(1,0))
#             +- nd_mid: :print
#             +- nd_args:
#                 @ NODE_LIST (id: 3, line: 1, location: (1,0)-(1,0))
#                 +- nd_alen: 1
#                 +- nd_head:
#                 |   @ NODE_GVAR (id: 2, line: 1, location: (1,0)-(1,0))
#                 |   +- nd_entry: :$_
#                 +- nd_next:
#                     (null node)

Could this mutation be moved into the compiler? That way it could be shared by prism, but also because it would make it less confusing when people are running --dump=parsetree as to why a loop is being inserted.

[nobu (Nobuyoshi Nakada)]

Moving -n/-p makes impossible to check break/next/redo in parser.

$ ruby -c -p -e break < /dev/null
Syntax OK

$ ruby -c -e break < /dev/null
-e:1: Invalid break
break
-e: compile error (SyntaxError)

[kddnewton (Kevin Newton)]

I assume in this case that you would still pass the settings into the parser so that it could be aware of it. In looking at parse.y, I think this would amount to calling allow_block_exit at the start.

[nobu (Nobuyoshi Nakada)]

Do you mean passing these to both of the parser and the compiler?

[kddnewton (Kevin Newton)]

I don't think you would have to pass all of the options, I think the only thing you would need to pass is "this is inside a while loop" in order to set up allow_block_exit properly.

[kddnewton (Kevin Newton)]

• Status changed from Open to Closed