Merges objects or arrays.
With objects:
merge {} # => {}
merge { a: 0 } # => { 'a' => 0 }
{}; merge _ # => {}
{ a: 0 }; merge _ # => { 'a' => 0 }
merge { a: 0 b: 1 } { b: 'B' c: 'C' }
# => { 'a' => 0, 'b' => 'B', 'c' => 'C' }
merge { b: 'B' c: 'C' } { a: 0 b: 1 }
# => { 'a' => 0, 'b' => 1, 'c' => 'C' },
With arrays:
merge [ 0 1 2 3 ] [ 'a' 'b' 'c' ]
# => [ 'a', 'b', 'c', 3 ],
merge [] # => []
merge [ 0 1 2 ] # => [ 0, 1, 2 ]
[]; merge _ # => []
[ 0 1 2 ]; merge _ # => [ 0, 1, 2 ]
It determines if it has to deal with arrays or objects by looking at its first argument (not the incoming ret).
It fails if the arguments are not all objects or not all arrays.
If the attribute lax: (or loose:) is set to true, it doesn't care
about non matching arguments and merges anyway:
merge { a: 0 } { b: 1 } 'nada' { c: 2 } lax: true
# => { 'a' => 0, 'b' => 1, 'c' => 2 }
merge { a: 0 } { b: 1 } { c: 2 }
# => { 'a' => 0, 'b' => 1, 'c' => 2 }
merge { a: 0 } { b: 1 } 'nada' { c: 2 } tags: 'xxx' loose: true
# => { 'a' => 0, 'b' => 1, 'c' => 2 }
strict: false is OK as well:
merge { a: 0 } { b: 1 } 'nada' { c: 2 } strict: false
# => { 'a' => 0, 'b' => 1, 'c' => 2 }
"merge" only draws in the incoming ret if necessary. If there are
enough arguments to perform a merge, the incoming ret will not be taken
into account.
You can add the incoming to the merge simply with f.ret.
[ 0 1 2 ]; merge [ 0 1 'deux' 3 ] # => [ 0 1 'deux' 3 ]
[ 0 1 2 3 4 ]; merge [ 0 1 2 3 ] [ 0 'un' 2 ] # => [ 0 'un' 2 3 ]
[ 0 1 2 3 4 ]; merge f.ret [ 0 1 2 3 ] [ 0 'un' 2 ] # => [ 0 'un' 2 3 ]
[ 0 1 2 3 4 ]; merge [ 0 1 2 3 ] [ 0 'un' 2 ] f.ret # => [ 0 1 2 3 4 ]
[ 0 ]; merge { a: 1 } { a: 'one' } # => { a: 'one' }