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Bug #20790
open
Syntax acceptance of `*x = p rescue p 1` is different between parse.y and prism
Bug #20790: Syntax acceptance of `*x = p rescue p 1` is different between parse.y and prism
Status:
Open
Assignee:
-
Target version:
-
ruby -v:
ruby 3.4.0dev (2024-10-09T03:27:05Z master ed11a244dd) +PRISM [x86_64-linux]
Description
*x = p rescue p 1 # syntax error in prism *x = p 1 rescue p 1 # both syntax ok x = p rescue p 1 # both syntax error x = p 1 rescue p 1 # both syntax ok Which is correct? If *x = p rescue p 1 is syntax valid, should x = p rescue p 1 also be syntax valid?
Updated by mame (Yusuke Endoh) about 1 year ago
- Related to Bug #8279: Single-line rescue parsing added
Updated by mame (Yusuke Endoh) about 1 year ago
Discussed at the dev meeting. Here is matz's preference.
# current parse.y behavior # matz's preference *x = p rescue p 1 # (*x = p) rescue (p 1) # *x = (p rescue (p 1)) *x = p 1 rescue p 1 # (*x = p 1) rescue (p 1) # *x = ((p 1) rescue (p 1)) a, b = p rescue p # a, b = (p rescue p) # as is x = p rescue p # x = (p rescue p) # as is x = p rescue p 1 # x = (p rescue p) 1 (ERROR) # x = (p rescue p 1) x = p 1 rescue p 1 # x = ((p 1) rescue (p 1)) # as is @yui-knk (Kaneko Yuichiro) @kddnewton (Kevin Newton) What do you think?
Updated by kddnewton (Kevin Newton) about 1 year ago
That makes sense to me, we can make that work.
Updated by ydah (Yudai Takada) 12 months ago
I checked if it is feasible with parse.y: https://github.com/ydah/ruby/commit/50100c136ac4bbe379b2c360994b739227610e17
I have been able to confirm that the following are feasible with the modifications shown above.
# current parse.y behavior # matz's preference *x = p rescue p 1 # (*x = p) rescue (p 1) # *x = (p rescue (p 1)) *x = p 1 rescue p 1 # (*x = p 1) rescue (p 1) # *x = ((p 1) rescue (p 1)) a, b = p rescue p # a, b = (p rescue p) # as is x = p rescue p # x = (p rescue p) # as is x = p 1 rescue p 1 # x = ((p 1) rescue (p 1)) # as is The following are still under investigation for feasibility.
# current parse.y behavior # matz's preference x = p rescue p 1 # x = (p rescue p) 1 (ERROR) # x = (p rescue p 1) Actions