func filterAbs(ctx stick.Context, val stick.Value, args ...stick.Value) stick.Value {
	n := stick.CoerceNumber(val)
	if 0 == n {
		return n
	}
	return math.Abs(n)
}
filterAbs takes no arguments and returns the absolute value of val.
Value val will be coerced into a number.
package filter  
import (
	"encoding/json"
	"fmt"
	"math"
	"sort"
	"strings"
	"unicode/utf8"
	"reflect"
	"time"
	"github.com/tyler-sommer/stick"
)
func TwigFilters() map[string]stick.Filter {
	return map[string]stick.Filter{
		"abs":              filterAbs,
		"default":          filterDefault,
		"batch":            filterBatch,
		"capitalize":       filterCapitalize,
		"convert_encoding": filterConvertEncoding,
		"date":             filterDate,
		"date_modify":      filterDateModify,
		"first":            filterFirst,
		"format":           filterFormat,
		"join":             filterJoin,
		"json_encode":      filterJSONEncode,
		"keys":             filterKeys,
		"last":             filterLast,
		"length":           filterLength,
		"lower":            filterLower,
		"merge":            filterMerge,
		"nl2br":            filterNL2BR,
		"number_format":    filterNumberFormat,
		"raw":              filterRaw,
		"replace":          filterReplace,
		"reverse":          filterReverse,
		"round":            filterRound,
		"slice":            filterSlice,
		"sort":             filterSort,
		"split":            filterSplit,
		"striptags":        filterStripTags,
		"title":            filterTitle,
		"trim":             filterTrim,
		"upper":            filterUpper,
		"url_encode":       filterURLEncode,
	}
}