String#concat has an "appending" behavior
Ruby String documentation (http://www.ruby-doc.org/core-2.2.0/String.html) introduces the two terms Appending and Concatenation:
- Concatenation (aka
+) —Returns a new String containing other_str concatenated to str.
- Append (aka
<<) —Concatenates the given object to str.
concat results in an appending operation. I find this particularly confusing and against the Principle of Least Surprise (e.g. I'd expect
concat to actually concatenate something). On the other hand I understand that changing such a small method would result in a quite significant breaking change.
Do you see this as an inconsistency? If yes, is there any particular design (or historical) reason behind it?
P.s. Seems like this is the case for
Array as well.
Updated by as-cii (Antonio Scandurra) about 5 years ago
Tsuyoshi Sawada wrote:
I can't find the place in the documentation that says "Concatenation (aka +)". Is this your own claim? If so, then that is not incorrect.
I'll copy over the relevant excerpts.
str + other_str → new_str Concatenation—Returns a new String containing other_str concatenated to str.
str << integer → str str << obj → str Append—Concatenates the given object to str. If the object is a Integer, it is considered as a codepoint, and is converted to a character before concatenation.
concat is defined as:
concat(integer) → str concat(obj) → str Append—Concatenates the given object to str. If the object is a Integer, it is considered as a codepoint, and is converted to a character before concatenation.
I summarized what I had read in the documentation, therefore it was not an exact quote.