Ruby

Summary¶

The result of Ripper.sexp differs between normal method definition and endless method definition.

Normal method definition¶

% ruby -rripper -e "pp Ripper.sexp('def m(a) foo end')" [:program, [[:def, [:@ident, "m", [1, 4]], [:paren, [:params, [[:@ident, "a", [1, 6]]], nil, nil, nil, nil, nil, nil]], [:bodystmt, [[:vcall, [:@ident, "foo", [1, 9]]]], nil, nil, nil]]]] 

Endless method definition¶

% ruby -rripper -e "pp Ripper.sexp('def m(a) = foo')" [:program, [[:def, [:@ident, "m", [1, 4]], [:paren, [:params, [[:@ident, "a", [1, 6]]], nil, nil, nil, nil, nil, nil]], [:vcall, [:@ident, "foo", [1, 11]]]]]] 

Endless method definition does not have bodystmt. Is it an expected behavior that these results differ?

This is reproduced in Ruby 3.1.0-dev and Ruby 3.0.1.

Additional Information¶

Their results are the same when using RubyVM::AbstractSyntaxTree.parse and ruby --dump=p.

RubyVM::AbstractSyntaxTree.parse¶

The following returns the same AST.

% ruby -e "pp RubyVM::AbstractSyntaxTree.parse('def m(a) foo end')" (SCOPE@1:0-1:16 tbl: [] args: nil body: (DEFN@1:0-1:16 mid: :m body: (SCOPE@1:0-1:16 tbl: [:a] args: (ARGS@1:6-1:7 pre_num: 1 pre_init: nil opt: nil first_post: nil post_num: 0 post_init: nil rest: nil kw: nil kwrest: nil block: nil) body: (VCALL@1:9-1:12 :foo)))) % ruby -e "pp RubyVM::AbstractSyntaxTree.parse('def m(a) = foo')" (SCOPE@1:0-1:14 tbl: [] args: nil body: (DEFN@1:0-1:14 mid: :m body: (SCOPE@1:0-1:14 tbl: [:a] args: (ARGS@1:6-1:7 pre_num: 1 pre_init: nil opt: nil first_post: nil post_num: 0 post_init: nil rest: nil kw: nil kwrest: nil block: nil) body: (VCALL@1:11-1:14 :foo)))) 

ruby --dump=p¶

The following returns the same parsetree.

% ruby --dump=p -e 'def m(a) foo end' ########################################################### ## Do NOT use this node dump for any purpose other than  ## ## debug and research.  Compatibility is not guaranteed. ## ###########################################################  # @ NODE_SCOPE (line: 1, location: (1,0)-(1,16)) # +- nd_tbl: (empty) # +- nd_args: # |   (null node) # +- nd_body: #     @ NODE_DEFN (line: 1, location: (1,0)-(1,16))* #     +- nd_mid: :m #     +- nd_defn: #         @ NODE_SCOPE (line: 1, location: (1,0)-(1,16)) #         +- nd_tbl: :a #         +- nd_args: #         |   @ NODE_ARGS (line: 1, location: (1,6)-(1,7)) #         |   +- nd_ainfo->pre_args_num: 1 #         |   +- nd_ainfo->pre_init: #         |   |   (null node) #         |   +- nd_ainfo->post_args_num: 0 #         |   +- nd_ainfo->post_init: #         |   |   (null node) #         |   +- nd_ainfo->first_post_arg: (null) #         |   +- nd_ainfo->rest_arg: (null) #         |   +- nd_ainfo->block_arg: (null) #         |   +- nd_ainfo->opt_args: #         |   |   (null node) #         |   +- nd_ainfo->kw_args: #         |   |   (null node) #         |   +- nd_ainfo->kw_rest_arg: #         |       (null node) #         +- nd_body: #             @ NODE_VCALL (line: 1, location: (1,9)-(1,12))* #             +- nd_mid: :foo  % ruby --dump=p -e 'def m(a) = foo' ########################################################### ## Do NOT use this node dump for any purpose other than ## ## debug and research. Compatibility is not guaranteed. ## ###########################################################  # @ NODE_SCOPE (line: 1, location: (1,0)-(1,14)) # +- nd_tbl: (empty) # +- nd_args: # | (null node) # +- nd_body: # @ NODE_DEFN (line: 1, location: (1,0)-(1,14))* # +- nd_mid: :m # +- nd_defn: # @ NODE_SCOPE (line: 1, location: (1,0)-(1,14)) # +- nd_tbl: :a # +- nd_args: # | @ NODE_ARGS (line: 1, location: (1,6)-(1,7)) # | +- nd_ainfo->pre_args_num: 1 # | +- nd_ainfo->pre_init: # | | (null node) # | +- nd_ainfo->post_args_num: 0 # | +- nd_ainfo->post_init: # | | (null node) # | +- nd_ainfo->first_post_arg: (null) # | +- nd_ainfo->rest_arg: (null) # | +- nd_ainfo->block_arg: (null) # | +- nd_ainfo->opt_args: # | | (null node) # | +- nd_ainfo->kw_args: # | | (null node) # | +- nd_ainfo->kw_rest_arg: # | (null node) # +- nd_body: # @ NODE_VCALL (line: 1, location: (1,11)-(1,14)) # +- nd_mid: :foo 

I noticed the issue because a 3rd party parser builds the same AST.

% ruby-parse -e 'def m(a) = foo' warning: parser/current is loading parser/ruby31, which recognizes warning: 3.1.0-dev-compliant syntax, but you are running 3.1.0. warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri. (def :m (args (arg :a)) (send nil :foo)) % ruby-parse -e 'def m(a) foo end' warning: parser/current is loading parser/ruby31, which recognizes warning: 3.1.0-dev-compliant syntax, but you are running 3.1.0. warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri. (def :m (args (arg :a)) (send nil :foo))