Metaoperators
In Sidef we have an interesting set of metaoperators, which provide an easier way of working with arrays and matrices.

Unroll operator

It's a nice metaoperator borrowed from Perl 6, which unrolls two arrays and applies the operator on each two element-wise objects, creating a new array with the results. The operator can be a method or any other valid operator and must be enclosed between » « or >> <<.
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[1,2,3] »+« [4,5,6] # [1+4, 2+5, 3+6]
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%w(a b c) >>cmp<< %w(c b a) # [-1, 0, 1]
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Internally, the unroll_operator method is called, which can, also, be implemented in user-defined classes.

Map operator

The array map operator works exactly like the Array.map{} method, but it's slightly more efficient and easier to write. The map operator must be enclosed between » » or >> >>.
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[1,2,3] »*» 4 # [1*4, 2*4, 3*4]
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Internally, the map_operator method is called.

Pam operator

The pam operator is kind of a reversed mapping of the array ("pam" is "map" spelled backwards), where the provided argument is used as the first operand to the operator provided. The operator must be enclosed between « « or << <<.
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[1,2,3] «/« 10 # [10/1, 10/2, 10/3]
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Internally, the pam_operator method is called.

Reduce operator

This metaoperator reduces an array to a single element. The operator needs to be enclosed inside « » or << >>.
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[1,2,3]«+» # 1 + 2 + 3
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[1,2,3]«/» # 1 / 2 / 3
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Internally, the reduce_operator method is called.

Cross operator

The metaoperator ~X or ~Xop crosses two arrays and returns a new one.
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[1,2] ~X+ [3,4] # [1+3, 1+4, 2+3, 2+4]
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[1,2] ~X [3,4] # [[1,3], [1,4], [2,3], [2,4]]
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Internally, the cross_operator method is called.

Zip operator

The metaoperator ~Z or ~Zop zips two arrays and returns a new one.
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[1,2] ~Z+ [3,4] # [1+3, 2+4]
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[1,2] ~Z [3,4] # [[1,3], [2,4]]
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Internally, the zip_operator method is called.

Wise operator

Almost equivalent with the zip metaoperator, it does element-wise folding on two arbitrary nested arrays, where both arrays must have the same structure.
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[1,2] ~W [3,4] # [[1,3], [2,4]]
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[1,2] ~W+ [3,4] # [1+3, 2+4]
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[[[1]],[2]] ~W+ [[[3]],[4]] # [[[1+3]], [2+4]]
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Internally, the wise_operator method is called.

Scalar operator

The scalar operator applies a given operator to the elements of an arbitrary nested array, where the provided scalar is used as the second operand to the given operator.
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[1,2,3] ~S 5 # [[1,5], [2,5], [3,5]]
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[1,2,3] ~S* 5 # [1*5, 2*5, 3*5]
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[1,[[2,[3]]]] ~S+ 5 # [1+5, [[2+5, [3+5]]]]
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Internally, the scalar_operator method is called.

Reverse scalar operator

The reverse scalar operator uses the given scalar as a first operand to the given operator and is also defined for arbitrary nested arrays.
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[3,4,5] ~RS 1 # [[1,3], [1,4], [1,5]]
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[3,4,5] ~RS/ 1 # [1/3, 1/4, 1/5]
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[3,[[4,[5]]]] ~RS/ 1 # [1/3, [[1/4, [1/5]]]]
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Internally, the rscalar_operator method is called.
Last modified 1yr ago