1// Copyright 2022 The Go Authors. All rights reserved.
  2// Use of this source code is governed by a BSD-style
  3// license that can be found in the LICENSE file.
  4
  5package slog
  6
  7import (
  8	"fmt"
  9	"time"
 10)
 11
 12// An Attr is a key-value pair.
 13type Attr struct {
 14	Key   string
 15	Value Value
 16}
 17
 18// String returns an Attr for a string value.
 19func String(key, value string) Attr {
 20	return Attr{key, StringValue(value)}
 21}
 22
 23// Int64 returns an Attr for an int64.
 24func Int64(key string, value int64) Attr {
 25	return Attr{key, Int64Value(value)}
 26}
 27
 28// Int converts an int to an int64 and returns
 29// an Attr with that value.
 30func Int(key string, value int) Attr {
 31	return Int64(key, int64(value))
 32}
 33
 34// Uint64 returns an Attr for a uint64.
 35func Uint64(key string, v uint64) Attr {
 36	return Attr{key, Uint64Value(v)}
 37}
 38
 39// Float64 returns an Attr for a floating-point number.
 40func Float64(key string, v float64) Attr {
 41	return Attr{key, Float64Value(v)}
 42}
 43
 44// Bool returns an Attr for a bool.
 45func Bool(key string, v bool) Attr {
 46	return Attr{key, BoolValue(v)}
 47}
 48
 49// Time returns an Attr for a time.Time.
 50// It discards the monotonic portion.
 51func Time(key string, v time.Time) Attr {
 52	return Attr{key, TimeValue(v)}
 53}
 54
 55// Duration returns an Attr for a time.Duration.
 56func Duration(key string, v time.Duration) Attr {
 57	return Attr{key, DurationValue(v)}
 58}
 59
 60// Group returns an Attr for a Group Value.
 61// The first argument is the key; the remaining arguments
 62// are converted to Attrs as in [Logger.Log].
 63//
 64// Use Group to collect several key-value pairs under a single
 65// key on a log line, or as the result of LogValue
 66// in order to log a single value as multiple Attrs.
 67func Group(key string, args ...any) Attr {
 68	return Attr{key, GroupValue(argsToAttrSlice(args)...)}
 69}
 70
 71func argsToAttrSlice(args []any) []Attr {
 72	var (
 73		attr  Attr
 74		attrs []Attr
 75	)
 76	for len(args) > 0 {
 77		attr, args = argsToAttr(args)
 78		attrs = append(attrs, attr)
 79	}
 80	return attrs
 81}
 82
 83// Any returns an Attr for the supplied value.
 84// See [Value.AnyValue] for how values are treated.
 85func Any(key string, value any) Attr {
 86	return Attr{key, AnyValue(value)}
 87}
 88
 89// Equal reports whether a and b have equal keys and values.
 90func (a Attr) Equal(b Attr) bool {
 91	return a.Key == b.Key && a.Value.Equal(b.Value)
 92}
 93
 94func (a Attr) String() string {
 95	return fmt.Sprintf("%s=%s", a.Key, a.Value)
 96}
 97
 98// isEmpty reports whether a has an empty key and a nil value.
 99// That can be written as Attr{} or Any("", nil).
100func (a Attr) isEmpty() bool {
101	return a.Key == "" && a.Value.num == 0 && a.Value.any == nil
102}