17 lines
527 B
Plaintext
17 lines
527 B
Plaintext
-- Refs are global mutable (changing) values.
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-- They let you break referential transparency (purity) to make some things easier.
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x = ref!(1337). -- Construct a new ref, set to the value 1337
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print(x). -- Should print <ref>
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print(readRef!(x)). -- Should print 1337
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setRef!(x, 42). -- Set it to 42
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print(readRef!(x)).
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-- Apply a function on the current value in the reference and set it to the new value.
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modifyRef!(ref, f) ->
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setRef!(ref, f(readRef!(ref))).
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modifyRef!(x, \v -> v*2). -- Double x
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print(readRef!(x)). -- 84
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