41 lines
785 B
Go
41 lines
785 B
Go
package main
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import (
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"fmt"
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"math"
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)
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type mwriter struct {
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value float64
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log string
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}
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func (m mwriter) bind(f func(v float64) mwriter) mwriter {
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n := f(m.value)
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n.log = m.log + n.log
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return n
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}
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func unit(v float64, s string) mwriter {
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return mwriter{v, fmt.Sprintf(" %-17s: %g\n", s, v)}
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}
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func root(v float64) mwriter {
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return unit(math.Sqrt(v), "Took square root")
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}
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func addOne(v float64) mwriter {
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return unit(v+1, "Added one")
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}
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func half(v float64) mwriter {
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return unit(v/2, "Divided by two")
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}
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func main() {
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mw1 := unit(5, "Initial value")
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mw2 := mw1.bind(root).bind(addOne).bind(half)
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fmt.Println("The Golden Ratio is", mw2.value)
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fmt.Println("\nThis was derived as follows:-")
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fmt.Println(mw2.log)
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}
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