42 lines
1007 B
Go
42 lines
1007 B
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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package main
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import (
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"errors"
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"fmt"
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"strconv"
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)
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// field helps for field parsing
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type field struct{ err error }
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// uatoi parses an unsigned integer string and saves the error.
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// it assumes that the val is unsigned.
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// for ease of usability: it returns an int instead of uint.
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func (f *field) uatoi(name, val string) int {
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n, err := strconv.Atoi(val)
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if err != nil || n < 0 {
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f.err = fmt.Errorf("incorrect field -> %q = %q", name, val)
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}
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return n
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}
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func atoi(input []byte) (int, error) {
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val := 0
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for i := 0; i < len(input); i++ {
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char := input[i]
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if char < '0' || char > '9' {
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return 0, errors.New("invalid number")
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}
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val = val*10 + int(char) - '0'
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}
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return val, nil
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}
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