Very minor work on recursion.

pretty.lua

@@ -196,7 +196,7 @@ local function escape_string (str)
 end
 
 local function get_function_info (f)
-    -- NOTE: Functions best in LuaJIT or Lua 5.2+
+    -- NOTE: Works best in LuaJIT or Lua 5.2+
 
     -- Regarding get-info:
     -- *  No need to includ 'f'. Function is already known
@@ -454,9 +454,11 @@ function format_table (t, options, depth, l)
 
     -- Empty or exteeding max-depth?
     if table_type == TABLE_TYPE_EMPTY then  l[#l+1] = '{}'; return
-    elseif depth ~= 'max' and depth >= options.max_depth then  l[#l+1] = '{...}'; return
+    elseif depth ~= 'max' and depth >= options.max_depth or l.visited[t] then  l[#l+1] = '{...}'; return
     end
 
+    l.visited[t] = true
+
     -- Single line?
     if is_single_line_table(t)  then  format_single_line_map(t, options, l); return  end
 
@@ -651,7 +653,7 @@ end
 --------------------------------------------------------------------------------
 
 local function pretty_format (value, options)
-    local l = {}
+    local l = { visited = { next_mark = 1 } }
     local options = options or {}
           options.max_depth = options.max_depth or math.huge
           options.indent    = options.indent    or '\t'

test/test_pretty.lua

@@ -650,6 +650,29 @@ format_test {
     expect = '{\n\t{ a = \'hello\', b = \'hi\'    },\n\t{ a = \'hi\',    b = \'hello\' }\n}',
 }
 
+--------------------------------------------------------------------------------
+-- Table recursion
+
+do
+    local recursive = {}
+          recursive[1] = recursive
+    format_test {
+        input   = recursive,
+        options = { max_depth = 5 },
+        expect  = '{ {...} }',
+    }
+    format_test {
+      input   = recursive,
+      options = { max_depth = 5, recursion = 'ignore' },
+      expect  = '{ {...} }',
+    }
+    format_test {
+      input   = recursive,
+      options = { max_depth = 5, recursion = 'marked' },
+      expect  = '<1>{ <1>{...} }',
+    }
+end
+
 
 --------------------------------------------------------------------------------
 -- Table Sorting