diff --git a/search.lua b/search.lua
index 37306f8..f7d4732 100644
--- a/search.lua
+++ b/search.lua
@@ -116,6 +116,8 @@ function find(s, pat, i, plain)
   return s:find(pat, i, plain)
 end
 
+-- TODO: avoid the expensive reverse() operations
+-- Particularly if we only care about literal matches, we don't need all of string.find
 function rfind(s, pat, i, plain)
   if s == nil then return end
   local rs = s:reverse()
diff --git a/text.lua b/text.lua
index 1833841..f868dc5 100644
--- a/text.lua
+++ b/text.lua
@@ -931,3 +931,27 @@ end
 function rtrim(s)
   return s:gsub('%s+$', '')
 end
+
+function starts_with(s, prefix)
+  if #s < #prefix then
+    return false
+  end
+  for i=1,#prefix do
+    if s:sub(i,i) ~= prefix:sub(i,i) then
+      return false
+    end
+  end
+  return true
+end
+
+function ends_with(s, suffix)
+  if #s < #suffix then
+    return false
+  end
+  for i=0,#suffix-1 do
+    if s:sub(#s-i,#s-i) ~= suffix:sub(#suffix-i,#suffix-i) then
+      return false
+    end
+  end
+  return true
+end