Omitting parens on function calls

You can omit parentheses on function calls in many cases.

foo(bar,baz)
foo bar,baz

This is even true if a function call doesn't have any parameters. (This is because all function calls and property accesses are just methods, by the way.)

puts(gets())
puts gets

This can be especially convenient if a call chain can be rearranged so only the last function takes an argument.

->{gets().split(",")}
->{gets.split ?,}

You can even omit parens in a situation like this. Keep in mind this will become ambiguous in some cases!

puts rand 10               # ok
print rand 10, " things"   # bad! tries rand(10, " things")
print rand(10), " things"  # ok

Notably, you can't omit parens if you pass an argument and a block to a function.

a.reduce{_1+_2}     # ok
a.reduce(0){_1+_2}  # ok
a.reduce 0{_1+_2}   # not ok

posted about 3 years ago

CC BY-NC 4.0

3y ago

snail_‭

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