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package httpcli
type (
// Opt defines a functional option for the HTTP client type. A functional option
// must return an Opt that acts as an "undo" if applied to the same Client.
Opt func(*Client) Opt
// Opts represents a series of functional options
Opts []Opt
)
// Apply is a nil-safe application of an Opt: if the receiver is nil then this func
// simply returns nil, otherwise it returns the result invoking the receiving Opt
// with the given Client.
func (o Opt) Apply(c *Client) (result Opt) {
if o != nil {
result = o(c)
}
return
}
// Merged generates a single Opt that applies all the functional options, in-order
func (opts Opts) Merged() Opt {
if len(opts) == 0 {
return nil
}
return func(c *Client) Opt {
var (
size = len(opts)
undo = make(Opts, size)
)
size-- // make this a zero-based offset
for i, opt := range opts {
if opt != nil {
undo[size-i] = opt(c)
}
}
return undo.Merged()
}
}
// And combines two functional options into a single Opt
func (o Opt) And(other Opt) Opt {
if o == nil {
if other == nil {
return nil
}
return other
}
if other == nil {
return o
}
return Opts{o, other}.Merged()
}
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