1 files changed, 78 insertions, 0 deletions
diff --git a/utils/markdown/inspect.go b/utils/markdown/inspect.go
new file mode 100644
index 000000000..c4e3bf1ac
--- /dev/null
+++ b/utils/markdown/inspect.go
@@ -0,0 +1,78 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+// Inspect traverses the markdown tree in depth-first order. If f returns true, Inspect invokes f
+// recursively for each child of the block or inline, followed by a call of f(nil).
+func Inspect(markdown string, f func(interface{}) bool) {
+	document, referenceDefinitions := Parse(markdown)
+	InspectBlock(document, func(block Block) bool {
+		if !f(block) {
+			return false
+		}
+		switch v := block.(type) {
+		case *Paragraph:
+			for _, inline := range v.ParseInlines(referenceDefinitions) {
+				InspectInline(inline, func(inline Inline) bool {
+					return f(inline)
+				})
+			}
+		}
+		return true
+	})
+}
+
+// InspectBlock traverses the blocks in depth-first order, starting with block. If f returns true,
+// InspectBlock invokes f recursively for each child of the block, followed by a call of f(nil).
+func InspectBlock(block Block, f func(Block) bool) {
+	if !f(block) {
+		return
+	}
+	switch v := block.(type) {
+	case *Document:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *List:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *ListItem:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *BlockQuote:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	}
+	f(nil)
+}
+
+// InspectInline traverses the blocks in depth-first order, starting with block. If f returns true,
+// InspectInline invokes f recursively for each child of the block, followed by a call of f(nil).
+func InspectInline(inline Inline, f func(Inline) bool) {
+	if !f(inline) {
+		return
+	}
+	switch v := inline.(type) {
+	case *InlineImage:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *InlineLink:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *ReferenceImage:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *ReferenceLink:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	}
+	f(nil)
+}