github.com/marinho/drone@v0.2.1-0.20140504195434-d3ba962e89a7/Godeps/_workspace/src/launchpad.net/goyaml/sorter.go (about)

     1  package goyaml
     2  
     3  import (
     4  	"reflect"
     5  	"unicode"
     6  )
     7  
     8  type keyList []reflect.Value
     9  
    10  func (l keyList) Len() int      { return len(l) }
    11  func (l keyList) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
    12  func (l keyList) Less(i, j int) bool {
    13  	a := l[i]
    14  	b := l[j]
    15  	ak := a.Kind()
    16  	bk := b.Kind()
    17  	for (ak == reflect.Interface || ak == reflect.Ptr) && !a.IsNil() {
    18  		a = a.Elem()
    19  		ak = a.Kind()
    20  	}
    21  	for (bk == reflect.Interface || bk == reflect.Ptr) && !b.IsNil() {
    22  		b = b.Elem()
    23  		bk = b.Kind()
    24  	}
    25  	af, aok := keyFloat(a)
    26  	bf, bok := keyFloat(b)
    27  	if aok && bok {
    28  		if af != bf {
    29  			return af < bf
    30  		}
    31  		if ak != bk {
    32  			return ak < bk
    33  		}
    34  		return numLess(a, b)
    35  	}
    36  	if ak != reflect.String || bk != reflect.String {
    37  		return ak < bk
    38  	}
    39  	ar, br := []rune(a.String()), []rune(b.String())
    40  	for i := 0; i < len(ar) && i < len(br); i++ {
    41  		if ar[i] == br[i] {
    42  			continue
    43  		}
    44  		al := unicode.IsLetter(ar[i])
    45  		bl := unicode.IsLetter(br[i])
    46  		if al && bl {
    47  			return ar[i] < br[i]
    48  		}
    49  		if al || bl {
    50  			return bl
    51  		}
    52  		var ai, bi int
    53  		var an, bn int64
    54  		for ai = i; ai < len(ar) && unicode.IsDigit(ar[ai]); ai++ {
    55  			an = an*10 + int64(ar[ai]-'0')
    56  		}
    57  		for bi = i; bi < len(br) && unicode.IsDigit(br[bi]); bi++ {
    58  			bn = bn*10 + int64(br[bi]-'0')
    59  		}
    60  		if an != bn {
    61  			return an < bn
    62  		}
    63  		if ai != bi {
    64  			return ai < bi
    65  		}
    66  		return ar[i] < br[i]
    67  	}
    68  	return len(ar) < len(br)
    69  }
    70  
    71  // keyFloat returns a float value for v if it is a number/bool
    72  // and whether it is a number/bool or not.
    73  func keyFloat(v reflect.Value) (f float64, ok bool) {
    74  	switch v.Kind() {
    75  	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
    76  		return float64(v.Int()), true
    77  	case reflect.Float32, reflect.Float64:
    78  		return v.Float(), true
    79  	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
    80  		return float64(v.Uint()), true
    81  	case reflect.Bool:
    82  		if v.Bool() {
    83  			return 1, true
    84  		}
    85  		return 0, true
    86  	}
    87  	return 0, false
    88  }
    89  
    90  // numLess returns whether a < b.
    91  // a and b must necessarily have the same kind.
    92  func numLess(a, b reflect.Value) bool {
    93  	switch a.Kind() {
    94  	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
    95  		return a.Int() < b.Int()
    96  	case reflect.Float32, reflect.Float64:
    97  		return a.Float() < b.Float()
    98  	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
    99  		return a.Uint() < b.Uint()
   100  	case reflect.Bool:
   101  		return !a.Bool() && b.Bool()
   102  	}
   103  	panic("not a number")
   104  }