func (es *ExpressionStats) ConsiderValue(val otto.Value) {
// increment the count
es.Count += 1
if val.IsNumber() {
f, err := val.ToFloat()
if err != nil {
log.Printf("Error converting number to float %v", err)
} else {
// update the sum
es.Sum += f
// if this is smaller than anything we've seen so far update the min
if f < es.Min {
es.Min = f
}
// if this is larger than anything we've seen so far update the max
if f > es.Max {
es.Max = f
}
// update the average (perhaps wasteful, could be done once at the end
// but i'd have to walk the whole tree again, for now will do update it each time
es.Avg = es.Sum / float64(es.Count) // we incremented es.count in this function, can not divide by 0
}
}
}
// Converts an Otto value to a Go value. Handles all JSON-compatible types.
func ottoToGo(value otto.Value) (interface{}, error) {
if value.IsBoolean() {
return value.ToBoolean()
} else if value.IsNull() || value.IsUndefined() {
return nil, nil
} else if value.IsNumber() {
return value.ToFloat()
} else if value.IsString() {
return value.ToString()
} else {
switch value.Class() {
case "Array":
return ottoToGoArray(value.Object())
}
}
return nil, fmt.Errorf("Unsupported Otto value: %v", value)
}
func convertToPrimitive(v otto.Value) interface{} {
if v.IsBoolean() {
v_b, err := v.ToBoolean()
if err != nil {
log.Printf("Error converting to boolean")
}
return v_b
} else if v.IsNumber() {
v_f, err := v.ToFloat()
if err != nil {
log.Printf("Error converting to float")
}
return v_f
} else {
v_s, err := v.ToString()
if err != nil {
log.Printf("Error converting to boolean")
}
return v_s
}
return nil
}
// Helper function to populate a sample structure with a single sample
func (sr *SampleReader) getSample() (*Sample, error) {
var err error
var v otto.Value
s := new(Sample)
// Extract date field from javascript runtime
v, err = sr.vm.Get("date")
if err != nil {
return nil, err
}
if !v.IsDefined() {
return nil, errors.New("date not defined")
}
ds, err := v.ToString()
if err != nil {
return nil, err
}
s.Date, err = time.Parse("2006-01-02T15:04:05", ds)
if err != nil {
return nil, err
}
// Extract latitude field from javascript runtime
v, err = sr.vm.Get("latitude")
if err != nil {
return nil, err
}
if !v.IsDefined() {
return nil, errors.New("latitude not defined")
}
s.Latitude, err = v.ToFloat()
if err != nil {
return nil, err
}
// Extract longitude field from javascript runtime
v, err = sr.vm.Get("longitude")
if err != nil {
return nil, err
}
if !v.IsDefined() {
return nil, errors.New("longitude not defined")
}
s.Longitude, err = v.ToFloat()
if err != nil {
return nil, err
}
// Extract altitude field from javascript runtime
v, err = sr.vm.Get("altitude")
if err != nil {
return nil, err
}
if !v.IsDefined() {
return nil, errors.New("altitude not defined")
}
s.Altitude, err = v.ToFloat()
if err != nil {
return nil, err
}
// Extract value field from javascript runtime
v, err = sr.vm.Get("value")
if err != nil {
return nil, err
}
if !v.IsDefined() {
return nil, errors.New("value not defined")
}
s.Value, err = v.ToFloat()
if err != nil {
return nil, err
}
// Extract unit field from javascript runtime
v, err = sr.vm.Get("unit")
if err != nil {
return nil, err
}
if !v.IsDefined() {
return nil, errors.New("unit not defined")
}
s.Unit, err = v.ToString()
if err != nil {
return nil, err
}
return s, nil
}
