variable_handling.go

package pgo

import (
	"reflect"
	"strings"
)

// like laravel blank
func Blank(val interface{}) bool {
	if val == nil {
		return true
	}

	if IsNumeric(val) {
		return false
	}

	v := reflect.ValueOf(val)
	switch v.Kind() {
	case reflect.String, reflect.Array:
		return v.Len() == 0
	case reflect.Map, reflect.Slice:
		return v.Len() == 0 || v.IsNil()
	case reflect.Bool:
		return !v.Bool()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return v.Int() == 0
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return v.Uint() == 0
	case reflect.Float32, reflect.Float64:
		return v.Float() == 0
	case reflect.Interface, reflect.Ptr:
		return v.IsNil()
	}

	return reflect.DeepEqual(val, reflect.Zero(v.Type()).Interface())
}


func IsNumeric(val interface{}) bool {
	// 000
	if reflect.TypeOf(val).Kind() == reflect.Int {
		return true
	}

	switch val.(type) {
	case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64:
	case float32, float64, complex64, complex128:
		return true
	case string:
		str := val.(string)
		if str == "" {
			return false
		}
		// Trim any whitespace
		str = strings.TrimSpace(str)
		if str[0] == '-' || str[0] == '+' {
			if len(str) == 1 {
				return false
			}
			str = str[1:]		}
		// hex
		if len(str) > 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X') {
			for _, h := range str[2:] {
				if !((h >= '0' && h <= '9') || (h >= 'a' && h <= 'f') || (h >= 'A' && h <= 'F')) {
					return false
				}
			}
			return true
		}
		// 0-9,Point,Scientific
		p, s, l := 0, 0, len(str)
		for i, v := range str {
			if v == '.' { // Point
				if p > 0 || s > 0 || i+1 == l {
					return false
				}
				p = i
			} else if v == 'e' || v == 'E' { // Scientific
				if i == 0 || s > 0 || i+1 == l {
					return false
				}
				s = i
			} else if v < '0' || v > '9' {
				return false
			}
		}
		return true
	}

	return false
}