str.go

Documentation: os

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Simple conversions to avoid depending on strconv.
     6  
     7  package os
     8  
     9  // itox converts val (an int) to a hexdecimal string.
    10  func itox(val int) string {
    11  	if val < 0 {
    12  		return "-" + uitox(uint(-val))
    13  	}
    14  	return uitox(uint(val))
    15  }
    16  
    17  const hex = "0123456789abcdef"
    18  
    19  // uitox converts val (a uint) to a hexdecimal string.
    20  func uitox(val uint) string {
    21  	if val == 0 { // avoid string allocation
    22  		return "0x0"
    23  	}
    24  	var buf [20]byte // big enough for 64bit value base 16 + 0x
    25  	i := len(buf) - 1
    26  	for val >= 16 {
    27  		q := val / 16
    28  		buf[i] = hex[val%16]
    29  		i--
    30  		val = q
    31  	}
    32  	// val < 16
    33  	buf[i] = hex[val%16]
    34  	i--
    35  	buf[i] = 'x'
    36  	i--
    37  	buf[i] = '0'
    38  	return string(buf[i:])
    39  }
    40
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