47 lines
1.3 KiB
Go
47 lines
1.3 KiB
Go
// Copyright © 2018 Inanc Gumus
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// Learn Go Programming Course
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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//
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// For more tutorials : https://learngoprogramming.com
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// In-person training : https://www.linkedin.com/in/inancgumus/
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// Follow me on twitter: https://twitter.com/inancgumus
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// In the depths of the Go standard library's fmt package...
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// Printing functions use the handleMethods method.
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// Example:
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// var pocket money = 10
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// fmt.Println(pocket)
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// the argument can be any type of value
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// stores the pocket variable in the argument variable
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// ^
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// |
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func (p *pp) handleMethods(argument interface{}) (handled bool) {
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// ...
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// Checks whether a given argument is an error or an fmt.Stringer
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switch v := argument.(type) {
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// ...
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// If the argument is a Stringer, calls its String() method
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case Stringer:
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// ...
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// pocket.String()
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// ^
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// |
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p.fmtString(v.String(), verb)
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return
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}
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// ...
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}
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/*
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The original `handleMethods` code is more involved:
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https://github.com/golang/go/blob/6f51082da77a1d4cafd5b7af0db69293943f4066/src/fmt/print.go#L574
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-> 574#handleMethods(..)
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-> 627#Stringer type check: If `v` is a Stringer, run:
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-> 630#v.String()
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*/ |