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116 lines
2.5 KiB
CoffeeScript
116 lines
2.5 KiB
CoffeeScript
# Slicing and Splicing
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# --------------------
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# * Slicing
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# * Splicing
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# shared array
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shared = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
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#### Slicing
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test "basic slicing", ->
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arrayEq [7, 8, 9] , shared[7..9]
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arrayEq [2, 3] , shared[2...4]
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arrayEq [2, 3, 4, 5], shared[2...6]
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test "slicing with variables as endpoints", ->
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[a, b] = [1, 4]
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arrayEq [1, 2, 3, 4], shared[a..b]
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arrayEq [1, 2, 3] , shared[a...b]
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test "slicing with expressions as endpoints", ->
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[a, b] = [1, 3]
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arrayEq [2, 3, 4, 5, 6], shared[(a+1)..2*b]
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arrayEq [2, 3, 4, 5] , shared[a+1...(2*b)]
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test "unbounded slicing", ->
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arrayEq [7, 8, 9] , shared[7..]
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arrayEq [8, 9] , shared[-2..]
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arrayEq [9] , shared[-1...]
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arrayEq [0, 1, 2] , shared[...3]
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arrayEq [0, 1, 2, 3], shared[..-7]
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arrayEq shared , shared[..-1]
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arrayEq shared[0..8], shared[...-1]
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for a in [-shared.length..shared.length]
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arrayEq shared[a..] , shared[a...]
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for a in [-shared.length+1...shared.length]
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arrayEq shared[..a][...-1] , shared[...a]
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test "#930, #835, #831, #746 #624: inclusive slices to -1 should slice to end", ->
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arrayEq shared, shared[0..-1]
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arrayEq shared, shared[..-1]
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arrayEq shared.slice(1,shared.length), shared[1..-1]
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test "string slicing", ->
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str = "abcdefghijklmnopqrstuvwxyz"
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ok str[1...1] is ""
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ok str[1..1] is "b"
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ok str[1...5] is "bcde"
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ok str[0..4] is "abcde"
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ok str[-5..] is "vwxyz"
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#### Splicing
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test "basic splicing", ->
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ary = [0..9]
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ary[5..9] = [0, 0, 0]
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arrayEq [0, 1, 2, 3, 4, 0, 0, 0], ary
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ary = [0..9]
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ary[2...8] = []
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arrayEq [0, 1, 8, 9], ary
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test "unbounded splicing", ->
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ary = [0..9]
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ary[3..] = [9, 8, 7]
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arrayEq [0, 1, 2, 9, 8, 7]. ary
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ary[...3] = [7, 8, 9]
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arrayEq [7, 8, 9, 9, 8, 7], ary
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test "splicing with variables as endpoints", ->
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[a, b] = [1, 8]
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ary = [0..9]
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ary[a..b] = [2, 3]
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arrayEq [0, 2, 3, 9], ary
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ary = [0..9]
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ary[a...b] = [5]
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arrayEq [0, 5, 8, 9], ary
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test "splicing with expressions as endpoints", ->
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[a, b] = [1, 3]
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ary = [0..9]
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ary[ a+1 .. 2*b+1 ] = [4]
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arrayEq [0, 1, 4, 8, 9], ary
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ary = [0..9]
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ary[a+1...2*b+1] = [4]
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arrayEq [0, 1, 4, 7, 8, 9], ary
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test "splicing to the end, against a one-time function", ->
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ary = null
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fn = ->
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if ary
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throw 'err'
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else
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ary = [1, 2, 3]
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fn()[0..] = 1
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arrayEq ary, [1]
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test "the return value of a splice literal should be the RHS", ->
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ary = [0, 0, 0]
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eq (ary[0..1] = 2), 2
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ary = [0, 0, 0]
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eq (ary[0..] = 3), 3
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arrayEq [ary[0..0] = 0], [0]
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