4 ms·

I'm not so up on Java, could someone explain why they chose "->" for lambdas instead of the "=>" that C# and ES6 use, as those languages seem to me like they wo

by grokys 11y ago

I'm not so up on Java, could someone explain why they chose "->" for lambdas instead of the "=>" that C# and ES6 use, as those languages seem to me like they would be the first place to look for inspiration.

LoneWolf 11y ago
While I don't know the reason i like it because for me is easier to type -> than => (portuguese keyboard, TBH dont know the difference from english)
- Glide 11y ago
  The - and = are right next to each other on an English keyboard.
WaxProlix 11y ago
AFAIK that's actually non-standard. Haskell and (more importantly, maybe) C++11 use the single-line arrow (->), as do Erlang and various ML dialects (interestingly, F# uses the single-line notation, too, while C# does not). Probably other languages as well.
kodablah 11y ago
In addition to the other answers, I bet it's easier for a CFG to parse knowing that "->" can't also be "negate and greater than" (since negation is only a prefix op) whereas "=>" can easily be a fat arrow or greater-than-or-equal.
- serge2k 11y ago
  Why would that be any harder? The tokens are different.
  - kodablah 11y ago
    True, Java does not support => as an alternative for >= so the ambiguity does not exist. It was just a guess, but since it was probably not right, I decided to dig. This mail post[1] explains that the extra equals sign becomes a bit annoying w/ other equal signs in the same expression. 1 - http://mail.openjdk.java.net/pipermail/lambda-dev/2011-September/004021.html http://mail.openjdk.java.net/pipermail/lambda-dev/2011-Septe...
bigtunacan 11y ago
I have no idea why Java chose that, but thought it worth mentioning "->" has been in use for Ruby longer than the alternative .NET and ES6 syntax.
tajen 11y ago
I'm not an expert. C++ uses -> for pointer dereference, e.g. o->p refers to the property "p" of object "o". I would assume C# inherits from C++ and had to define another operator. Java probably followed Scala's notation, which is probably derived from mathematics where ↦ is an application (a function) and ⇒ is a simple logical implication.
- incepted 11y ago
  Actually Scala uses =>, so Java went the opposite way. Kotlin also uses ->. Doesn't matter much in the long run, you'll get used to whichever your language favors after just a few days or writing code in it.

by grokys 11y ago

LoneWolf 11y ago

While I don't know the reason i like it because for me is easier to type -> than => (portuguese keyboard, TBH dont know the difference from english)

Glide 11y ago
The - and = are right next to each other on an English keyboard.

WaxProlix 11y ago

AFAIK that's actually non-standard. Haskell and (more importantly, maybe) C++11 use the single-line arrow (->), as do Erlang and various ML dialects (interestingly, F# uses the single-line notation, too, while C# does not). Probably other languages as well.

kodablah 11y ago

In addition to the other answers, I bet it's easier for a CFG to parse knowing that "->" can't also be "negate and greater than" (since negation is only a prefix op) whereas "=>" can easily be a fat arrow or greater-than-or-equal.

serge2k 11y ago
Why would that be any harder? The tokens are different.
- kodablah 11y ago
  True, Java does not support => as an alternative for >= so the ambiguity does not exist. It was just a guess, but since it was probably not right, I decided to dig. This mail post[1] explains that the extra equals sign becomes a bit annoying w/ other equal signs in the same expression. 1 - http://mail.openjdk.java.net/pipermail/lambda-dev/2011-September/004021.html http://mail.openjdk.java.net/pipermail/lambda-dev/2011-Septe...

bigtunacan 11y ago

I have no idea why Java chose that, but thought it worth mentioning "->" has been in use for Ruby longer than the alternative .NET and ES6 syntax.

tajen 11y ago

I'm not an expert. C++ uses -> for pointer dereference, e.g. o->p refers to the property "p" of object "o". I would assume C# inherits from C++ and had to define another operator. Java probably followed Scala's notation, which is probably derived from mathematics where ↦ is an application (a function) and ⇒ is a simple logical implication.

incepted 11y ago
Actually Scala uses =>, so Java went the opposite way. Kotlin also uses ->. Doesn't matter much in the long run, you'll get used to whichever your language favors after just a few days or writing code in it.