diff --git a/common/attrlist.c b/common/attrlist.c
index e50ec141..cb0833bc 100644
--- a/common/attrlist.c
+++ b/common/attrlist.c
@@ -651,12 +651,14 @@ void attrlistRemoveCharacters(struct attrlist *alist, size_t start, size_t end)
 void attrlistForEach(struct attrlist *alist, uiAttributedString *s, uiAttributedStringForEachAttributeFunc f, void *data)
 {
 	struct attr *a;
+	uiForEach ret;
 
-	for (a = alist->first; a != NULL; a = a->next)
-		// TODO document this
-		// TODO should this be return 0 to break?
-		if ((*f)(s, &(a->spec), a->start, a->end, data))
+	for (a = alist->first; a != NULL; a = a->next) {
+		ret = (*f)(s, &(a->spec), a->start, a->end, data);
+		if (ret == uiForEachStop)
+			// TODO for all: break or return?
 			break;
+	}
 }
 
 struct attrlist *attrlistNew(void)
diff --git a/darwin/attrstr.m b/darwin/attrstr.m
index 6cf412a4..63539702 100644
--- a/darwin/attrstr.m
+++ b/darwin/attrstr.m
@@ -209,7 +209,7 @@ static CGColorRef mkcolor(uiAttributeSpec *spec)
 	return color;
 }
 
-static int processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t start, size_t end, void *data)
+static uiForEach processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t start, size_t end, void *data)
 {
 	struct foreachParams *p = (struct foreachParams *) data;
 	CFRange range;
@@ -316,7 +316,7 @@ static int processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t
 		// TODO complain
 		;
 	}
-	return 0;
+	return uiForEachContinue;
 }
 
 static BOOL cfaIsEqual(combinedFontAttr *a, combinedFontAttr *b)
diff --git a/darwin/opentype.m b/darwin/opentype.m
index 56bdc755..24f35f63 100644
--- a/darwin/opentype.m
+++ b/darwin/opentype.m
@@ -70,15 +70,18 @@ void uiOpenTypeFeaturesForEach(const uiOpenTypeFeatures *otf, uiOpenTypeFeatures
 		NSNumber *vn = (NSNumber *) value;
 		uint32_t tag;
 		uint8_t a, b, c, d;
+		uiForEach ret;
 
 		tag = mapObjectValue(tn);
 		a = (uint8_t) ((tag >> 24) & 0xFF);
 		b = (uint8_t) ((tag >> 16) & 0xFF);
 		c = (uint8_t) ((tag >> 8) & 0xFF);
 		d = (uint8_t) (tag & 0xFF);
-		// TODO handle return value
-		(*f)((char) a, (char) b, (char) c, (char) d,
+		ret = (*f)((char) a, (char) b, (char) c, (char) d,
 			mapObjectValue(vn), data);
+		// TODO for all: require exact match?
+		if (ret == uiForEachStop)
+			*stop = YES;
 	}];
 }
 
@@ -90,7 +93,7 @@ int uiOpenTypeFeaturesEqual(const uiOpenTypeFeatures *a, const uiOpenTypeFeature
 // TODO explain all this
 // TODO rename outerArray and innerDict (the names made sense when this was part of fontdescAppendFeatures(), but not here)
 // TODO make all this use enumerateKeysAndObjects (which requires duplicating code)?
-static int otfArrayForEachAAT(char a, char b, char c, char d, uint32_t value, void *data)
+static uiForEach otfArrayForEachAAT(char a, char b, char c, char d, uint32_t value, void *data)
 {
 	CFMutableArrayRef outerArray = (CFMutableArrayRef) data;
 
@@ -121,12 +124,11 @@ static int otfArrayForEachAAT(char a, char b, char c, char d, uint32_t value, vo
 		CFRelease(numSelector);
 		CFRelease(numType);
 	});
-	// TODO
-	return 0;
+	return uiForEachContinue;
 }
 
 // TODO find out which fonts differ in AAT small caps and test them with this
-static int otfArrayForEachOT(char a, char b, char c, char d, uint32_t value, void *data)
+static uiForEach otfArrayForEachOT(char a, char b, char c, char d, uint32_t value, void *data)
 {
 	CFMutableArrayRef outerArray = (CFMutableArrayRef) data;
 	CFDictionaryRef innerDict;
@@ -163,8 +165,7 @@ static int otfArrayForEachOT(char a, char b, char c, char d, uint32_t value, voi
 	CFRelease(innerDict);
 	CFRelease(numValue);
 	CFRelease(strTag);
-	// TODO
-	return 0;
+	return uiForEachContinue;
 }
 
 CFArrayRef otfToFeaturesArray(const uiOpenTypeFeatures *otf)
diff --git a/ui.h b/ui.h
index 922d0625..72e5eaef 100644
--- a/ui.h
+++ b/ui.h
@@ -34,6 +34,12 @@ extern "C" {
 
 // TODO uiBool?
 
+// uiForEach represents the return value from one of libui's various ForEach functions.
+_UI_ENUM(uiForEach) {
+	uiForEachContinue,
+	uiForEachStop,
+};
+
 typedef struct uiInitOptions uiInitOptions;
 
 struct uiInitOptions {
diff --git a/ui_attrstr.h b/ui_attrstr.h
index 2f41cebb..9dc72a5a 100644
--- a/ui_attrstr.h
+++ b/ui_attrstr.h
@@ -55,7 +55,7 @@ _UI_ENUM(uiDrawUnderlineColor) {
 // TODO rename?
 typedef struct uiOpenTypeFeatures uiOpenTypeFeatures;
 // TODO pass the feature set?
-typedef int (*uiOpenTypeFeaturesForEachFunc)(char a, char b, char c, char d, uint32_t value, void *data);
+typedef uiForEach (*uiOpenTypeFeaturesForEachFunc)(char a, char b, char c, char d, uint32_t value, void *data);
 // TODO detailed constructor?
 _UI_EXTERN uiOpenTypeFeatures *uiNewOpenTypeFeatures(void);
 _UI_EXTERN void uiFreeOpenTypeFeatures(uiOpenTypeFeatures *otf);
@@ -83,9 +83,8 @@ struct uiAttributeSpec {
 	const uiOpenTypeFeatures *Features;	// TODO rename to OpenTypeFeatures?
 };
 
-// TODO name the foreach return values
 // TODO make the spec const in a way that doesn't allow fields to be modified?
-typedef int (*uiAttributedStringForEachAttributeFunc)(uiAttributedString *s, uiAttributeSpec *spec, size_t start, size_t end, void *data);
+typedef uiForEach (*uiAttributedStringForEachAttributeFunc)(uiAttributedString *s, uiAttributeSpec *spec, size_t start, size_t end, void *data);
 
 // @role uiAttributedString constructor
 // uiNewAttributedString() creates a new uiAttributedString from
diff --git a/unix/attrstr.c b/unix/attrstr.c
index 7f12fff8..7dc83a6e 100644
--- a/unix/attrstr.c
+++ b/unix/attrstr.c
@@ -65,7 +65,7 @@ static void addattr(struct foreachParams *p, size_t start, size_t end, PangoAttr
 	pango_attr_list_insert(p->attrs, attr);
 }
 
-static int processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t start, size_t end, void *data)
+static uiForEach processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t start, size_t end, void *data)
 {
 	struct foreachParams *p = (struct foreachParams *) data;
 	GClosure *closure;
@@ -164,7 +164,7 @@ static int processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t
 		// TODO complain
 		;
 	}
-	return 0;
+	return uiForEachContinue;
 }
 
 static void unrefClosure(gpointer data)
diff --git a/unix/opentype.c b/unix/opentype.c
index 608a0815..9b90d0ba 100644
--- a/unix/opentype.c
+++ b/unix/opentype.c
@@ -78,7 +78,7 @@ int uiOpenTypeFeaturesGet(uiOpenTypeFeatures *otf, char a, char b, char c, char
 struct otfForEach {
 	uiOpenTypeFeaturesForEachFunc f;
 	void *data;
-	// TODO store continuation status here
+	uiForEach ret;
 };
 
 static void foreach(gpointer key, gpointer value, gpointer data)
@@ -87,13 +87,15 @@ static void foreach(gpointer key, gpointer value, gpointer data)
 	uint32_t tag;
 	uint8_t a, b, c, d;
 
+	// we can't stop early, so just ignore the rest if we have to
+	if (ofe->ret == uiForEachStop)
+		return;
 	tag = GPOINTER_TO_INT(key);
 	a = (uint8_t) ((tag >> 24) & 0xFF);
 	b = (uint8_t) ((tag >> 16) & 0xFF);
 	c = (uint8_t) ((tag >> 8) & 0xFF);
 	d = (uint8_t) (tag & 0xFF);
-	// TODO handle return value
-	(*(ofe->f))((char) a, (char) b, (char) c, (char) d, GPOINTER_TO_INT(value), ofe->data);
+	ofe->ret = (*(ofe->f))((char) a, (char) b, (char) c, (char) d, GPOINTER_TO_INT(value), ofe->data);
 }
 
 void uiOpenTypeFeaturesForEach(const uiOpenTypeFeatures *otf, uiOpenTypeFeaturesForEachFunc f, void *data)
@@ -175,7 +177,7 @@ out:
 
 // see https://developer.mozilla.org/en/docs/Web/CSS/font-feature-settings
 // TODO make this a g_hash_table_foreach() function (which requires duplicating code)?
-static int toCSS(char a, char b, char c, char d, uint32_t value, void *data)
+static uiForEach toCSS(char a, char b, char c, char d, uint32_t value, void *data)
 {
 	// TODO is there a G_STRING()?
 	GString *s = (GString *) data;
@@ -183,8 +185,7 @@ static int toCSS(char a, char b, char c, char d, uint32_t value, void *data)
 	// the last trailing comma is removed after foreach is done
 	g_string_append_printf(s, "\"%c%c%c%c\" %" PRIu32 ", ",
 		a, b, c, d, value);
-	// TODO use this
-	return 0;
+	return uiForEachContinue;
 }
 
 gchar *otfToPangoCSSString(const uiOpenTypeFeatures *otf)
diff --git a/windows/attrstr.cpp b/windows/attrstr.cpp
index 71f753d4..7bcd5e53 100644
--- a/windows/attrstr.cpp
+++ b/windows/attrstr.cpp
@@ -49,7 +49,7 @@ static backgroundFunc mkBackgroundFunc(size_t start, size_t end, double r, doubl
 	};
 }
 
-static int processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t start, size_t end, void *data)
+static uiForEach processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t start, size_t end, void *data)
 {
 	struct foreachParams *p = (struct foreachParams *) data;
 	DWRITE_TEXT_RANGE range;
@@ -184,7 +184,7 @@ static int processAttribute(uiAttributedString *s, uiAttributeSpec *spec, size_t
 		// TODO complain
 		;
 	}
-	return 0;
+	return uiForEachContinue;
 }
 
 static void applyAndFreeEffectsAttributes(struct foreachParams *p)
diff --git a/windows/opentype.cpp b/windows/opentype.cpp
index 0275d916..21833e2c 100644
--- a/windows/opentype.cpp
+++ b/windows/opentype.cpp
@@ -64,14 +64,16 @@ void uiOpenTypeFeaturesForEach(const uiOpenTypeFeatures *otf, uiOpenTypeFeatures
 	end = otf->tags->end();
 	for (iter = otf->tags->begin(); iter != end; iter++) {
 		uint8_t a, b, c, d;
+		uiForEach ret;
 
 		a = (uint8_t) (iter->first & 0xFF);
 		b = (uint8_t) ((iter->first >> 8) & 0xFF);
 		c = (uint8_t) ((iter->first >> 16) & 0xFF);
 		d = (uint8_t) ((iter->first >> 24) & 0xFF);
-		// TODO handle return value
-		(*f)((char) a, (char) b, (char) c, (char) d,
+		ret = (*f)((char) a, (char) b, (char) c, (char) d,
 			iter->second, data);
+		if (ret == uiForEachStop)
+			return;
 	}
 }