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|
package walk
import (
"math"
"fmt"
)
type AtomType int64
const (
AtomNull AtomType = iota
AtomBool
AtomNumber
AtomTerminal
AtomStringTerminal
AtomStringRune
)
type Atom struct {
Typ AtomType
data uint64
}
func NewAtomNull() Atom {
return Atom {
Typ: AtomNull,
data: 0,
}
}
func NewAtomBool(v bool) Atom {
if v {
return Atom {
Typ: AtomBool,
data: 1,
}
} else {
return Atom {
Typ: AtomBool,
data: 0,
}
}
}
func NewAtomNumber(v float64) Atom {
return Atom {
Typ: AtomNumber,
data: math.Float64bits(v),
}
}
func (v Atom) Number() float64 {
if v.Typ != AtomNumber {
panic("Tried to use non-number as number")
}
return math.Float64frombits(v.data)
}
func NewAtomTerminal(v ValueTerminal) Atom {
return Atom {
Typ: AtomTerminal,
data: uint64(v),
}
}
func (v Atom) Terminal() ValueTerminal {
if v.Typ != AtomTerminal {
panic("Tried to use non-terminal as terminal")
}
return ValueTerminal(v.data)
}
func NewAtomStringTerminal() Atom {
return Atom {
Typ: AtomStringTerminal,
data: 0,
}
}
func NewAtomStringRune(v rune) Atom {
return Atom {
Typ: AtomStringRune,
data: uint64(v),
}
}
func (v Atom) String() string {
switch v.Typ {
case AtomNull:
return "null"
case AtomBool:
if v.data == 0 {
return "false"
}
return "true"
case AtomNumber:
return fmt.Sprintf("%v", math.Float64frombits(v.data))
case AtomTerminal:
switch ValueTerminal(v.data) {
case MapBegin:
return "{"
case MapEnd:
return "}"
case ArrayBegin:
return "["
case ArrayEnd:
return "]"
default:
panic("Invalid terminal atom")
}
case AtomStringTerminal:
return "\""
case AtomStringRune:
return string(rune(v.data))
default:
panic("Invalid atom type")
}
}
|
