From 08d6943dd1cc20462e8edeead0684fb45e20ec25 Mon Sep 17 00:00:00 2001
From: fiatjaf <fiatjaf@gmail.com>
Date: Tue, 31 Dec 2024 23:09:56 -0300
Subject: [PATCH] references returns an iterator because why not?

---
 sdk/references.go | 140 +++++++++++++++++++++++-----------------------
 1 file changed, 70 insertions(+), 70 deletions(-)

diff --git a/sdk/references.go b/sdk/references.go
index 3c73be5..f16b6b8 100644
--- a/sdk/references.go
+++ b/sdk/references.go
@@ -1,6 +1,7 @@
 package sdk
 
 import (
+	"iter"
 	"regexp"
 	"strconv"
 	"strings"
@@ -21,88 +22,87 @@ type Reference struct {
 var mentionRegex = regexp.MustCompile(`\bnostr:((note|npub|naddr|nevent|nprofile)1\w+)\b|#\[(\d+)\]`)
 
 // ParseReferences parses both NIP-08 and NIP-27 references in a single unifying interface.
-func ParseReferences(evt *nostr.Event) []*Reference {
-	var references []*Reference
-	content := evt.Content
+func ParseReferences(evt nostr.Event) iter.Seq[Reference] {
+	return func(yield func(Reference) bool) {
+		for _, ref := range mentionRegex.FindAllStringSubmatchIndex(evt.Content, -1) {
+			reference := Reference{
+				Text:  evt.Content[ref[0]:ref[1]],
+				Start: ref[0],
+				End:   ref[1],
+			}
 
-	for _, ref := range mentionRegex.FindAllStringSubmatchIndex(evt.Content, -1) {
-		reference := &Reference{
-			Text:  content[ref[0]:ref[1]],
-			Start: ref[0],
-			End:   ref[1],
-		}
+			if ref[6] == -1 {
+				// didn't find a NIP-10 #[0] reference, so it's a NIP-27 mention
+				nip19code := evt.Content[ref[2]:ref[3]]
 
-		if ref[6] == -1 {
-			// didn't find a NIP-10 #[0] reference, so it's a NIP-27 mention
-			nip19code := content[ref[2]:ref[3]]
-
-			if prefix, data, err := nip19.Decode(nip19code); err == nil {
-				switch prefix {
-				case "npub":
-					reference.Profile = &nostr.ProfilePointer{
-						PublicKey: data.(string), Relays: []string{},
+				if prefix, data, err := nip19.Decode(nip19code); err == nil {
+					switch prefix {
+					case "npub":
+						reference.Profile = &nostr.ProfilePointer{
+							PublicKey: data.(string), Relays: []string{},
+						}
+					case "nprofile":
+						pp := data.(nostr.ProfilePointer)
+						reference.Profile = &pp
+					case "note":
+						reference.Event = &nostr.EventPointer{ID: data.(string), Relays: []string{}}
+					case "nevent":
+						evp := data.(nostr.EventPointer)
+						reference.Event = &evp
+					case "naddr":
+						addr := data.(nostr.EntityPointer)
+						reference.Entity = &addr
 					}
-				case "nprofile":
-					pp := data.(nostr.ProfilePointer)
-					reference.Profile = &pp
-				case "note":
-					reference.Event = &nostr.EventPointer{ID: data.(string), Relays: []string{}}
-				case "nevent":
-					evp := data.(nostr.EventPointer)
-					reference.Event = &evp
-				case "naddr":
-					addr := data.(nostr.EntityPointer)
-					reference.Entity = &addr
 				}
-			}
-		} else {
-			// it's a NIP-10 mention.
-			// parse the number, get data from event tags.
-			n := content[ref[6]:ref[7]]
-			idx, err := strconv.Atoi(n)
-			if err != nil || len(evt.Tags) <= idx {
-				continue
-			}
-			if tag := evt.Tags[idx]; tag != nil && len(tag) >= 2 {
-				switch tag[0] {
-				case "p":
-					relays := make([]string, 0, 1)
-					if len(tag) > 2 && tag[2] != "" {
-						relays = append(relays, tag[2])
-					}
-					reference.Profile = &nostr.ProfilePointer{
-						PublicKey: tag[1],
-						Relays:    relays,
-					}
-				case "e":
-					relays := make([]string, 0, 1)
-					if len(tag) > 2 && tag[2] != "" {
-						relays = append(relays, tag[2])
-					}
-					reference.Event = &nostr.EventPointer{
-						ID:     tag[1],
-						Relays: relays,
-					}
-				case "a":
-					if parts := strings.Split(tag[1], ":"); len(parts) == 3 {
-						kind, _ := strconv.Atoi(parts[0])
+			} else {
+				// it's a NIP-10 mention.
+				// parse the number, get data from event tags.
+				n := evt.Content[ref[6]:ref[7]]
+				idx, err := strconv.Atoi(n)
+				if err != nil || len(evt.Tags) <= idx {
+					continue
+				}
+				if tag := evt.Tags[idx]; tag != nil && len(tag) >= 2 {
+					switch tag[0] {
+					case "p":
 						relays := make([]string, 0, 1)
 						if len(tag) > 2 && tag[2] != "" {
 							relays = append(relays, tag[2])
 						}
-						reference.Entity = &nostr.EntityPointer{
-							Identifier: parts[2],
-							PublicKey:  parts[1],
-							Kind:       kind,
-							Relays:     relays,
+						reference.Profile = &nostr.ProfilePointer{
+							PublicKey: tag[1],
+							Relays:    relays,
+						}
+					case "e":
+						relays := make([]string, 0, 1)
+						if len(tag) > 2 && tag[2] != "" {
+							relays = append(relays, tag[2])
+						}
+						reference.Event = &nostr.EventPointer{
+							ID:     tag[1],
+							Relays: relays,
+						}
+					case "a":
+						if parts := strings.Split(tag[1], ":"); len(parts) == 3 {
+							kind, _ := strconv.Atoi(parts[0])
+							relays := make([]string, 0, 1)
+							if len(tag) > 2 && tag[2] != "" {
+								relays = append(relays, tag[2])
+							}
+							reference.Entity = &nostr.EntityPointer{
+								Identifier: parts[2],
+								PublicKey:  parts[1],
+								Kind:       kind,
+								Relays:     relays,
+							}
 						}
 					}
 				}
 			}
+
+			if !yield(reference) {
+				return
+			}
 		}
-
-		references = append(references, reference)
 	}
-
-	return references
 }