Bug #9242: Rdoc detection of aliases

• Status: Closed
• Assignee: drbrain (Eric Hodel)
• Target version: -
• ruby -v: 2.1.0 preview
• Tags: patch, lib

[marcandre (Marc-Andre Lafortune)]

The online doc appears to be making bad detection of aliases.

For example, Array#map and Array#collect are not marked as aliases (on either ruby-doc.org or docs.ruby-lang.org)

On the other hand, when aliases are detected, the generated method interface and the name of the method it is aliases to are always the same for both methods.

For example, the doc for Array#find_index says it is an alias to find_index and has interface showing index (again on both sites), e.g. http://docs.ruby-lang.org/en/2.0.0/Array.html#method-i-find_index

It might also be a good idea to always have doc examples using both forms in case of aliases.

[Hanmac (Hans Mackowiak)]

Array#map and Array#collect are not real aliases
both methods are defined with the excact same method body function but both are not calling each other,
so changeing one method doe not break the other

[zzak (zzak _)]

• Status changed from Open to Assigned
• Assignee changed from drbrain (Eric Hodel) to zzak (zzak _)

Alias detection was updated in the pre-release of RDoc 4.1.0, can you try to test it?

If it's these methods are using the same method, we can easily fix this by adding another signature to the call-seq example. What do you think?

[drbrain (Eric Hodel)]

• Assignee changed from zzak (zzak _) to drbrain (Eric Hodel)
• Target version set to 2.6

As Hanmac noted, they aren't real aliases:

$ grep rb_ary_collect array.c
rb_ary_collect(VALUE ary)
rb_ary_collect_bang(VALUE ary)
rb_define_method(rb_cArray, "collect", rb_ary_collect, 0);
rb_define_method(rb_cArray, "collect!", rb_ary_collect_bang, 0);
rb_define_method(rb_cArray, "map", rb_ary_collect, 0);
rb_define_method(rb_cArray, "map!", rb_ary_collect_bang, 0);

But I guess this is for performance reasons (can someone confirm?). I suppose RDoc should treat these as aliases.

[marcandre (Marc-Andre Lafortune)]

There really shouldn't be a difference between using rb_define_alias and using the same rb_define_method.

In Ruby, Array.instance_method(:map) == Array.instance_method(:collect) returns true (even when not defined using rb_define_alias), and they should be treated as aliases.

Moreover, the problem isn't there, since Array#find_index and index are not defined using rb_define_alias either but the generated doc sees them as aliases.

[zzak (zzak _)]

• Category changed from doc to lib

[naruse (Yui NARUSE)]

• Target version deleted (2.6)

[jeremyevans0 (Jeremy Evans)]

• Backport deleted (1.9.3: UNKNOWN, 2.0.0: UNKNOWN)

This is still an issue in the master branch. I've added a pull request for rdoc that will treat rb_define_method to the same C function as an alias (similar to rb_define_alias): https://github.com/ruby/rdoc/pull/742

[jeremyevans0 (Jeremy Evans)]

• Status changed from Assigned to Closed