Output descriptors: wpkh fragment support

descriptor/descriptor.go

@@ -0,0 +1,43 @@
+package descriptor
+
+// Wallet is interface to be implemented by various descriptor wallets
+type Wallet interface {
+	// Type returns type of descriptor wallet (e.g. wpkh, wsh etc.)
+	Type() string
+	// IsRange returns true if wallet description is of type range which means
+	//that key expression provides master key and requires more scripts to be generated
+	IsRange() bool
+	// Script generates new script, or range of scripts depending on wallet description
+	//it returns ScriptResponse which holds script and its derivation path in case wallet descriptor is range
+	//if it isn't derivation path will be nil
+	//wits ScriptOpts pkg user can specify how many scripts should be generated in case of
+	//range wallet descriptor, it also can specify exact index
+	Script(opts *ScriptOpts) ([]ScriptResponse, error)
+}
+
+// ScriptResponse defines response for Script func
+type ScriptResponse struct {
+	DerivationPath []uint32
+	Script         []byte
+}
+
+// ScriptOpts defines options for range type of descriptor wallet
+type ScriptOpts struct {
+	index        *uint32
+	numOfScripts *int
+}
+
+// WithIndex defines exact child index for which script should be generated for
+//range wallet descriptor
+func WithIndex(index uint32) *ScriptOpts {
+	return &ScriptOpts{
+		index: &index,
+	}
+}
+
+// WithRange defines how many scripts should be generated for range wallet descriptor
+func WithRange(numOfScrips int) *ScriptOpts {
+	return &ScriptOpts{
+		numOfScripts: &numOfScrips,
+	}
+}