1 files changed, 146 insertions, 0 deletions
diff --git a/upb/bindings/lua/upb.lua b/upb/bindings/lua/upb.lua
new file mode 100644
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+++ b/upb/bindings/lua/upb.lua
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+--
+-- upb - a minimalist implementation of protocol buffers.
+--
+-- Copyright (c) 2009 Google Inc.  See LICENSE for details.
+-- Author: Josh Haberman <jhaberman@gmail.com>
+--
+-- Pure-Lua support functions that are part of the "upb" module.
+-- This file is embedded and packaged into the "upb" C module binary -- it
+-- should not be installed or used directly!
+
+return function(upb)
+  -- A convenience function for building/linking/freezing defs
+  -- while maintaining their original order.
+  --
+  -- Sample usage:
+  --   local m1, m2 = upb.build_defs{
+  --     upb.MessageDef{full_name = "M1", fields = {
+  --         upb.FieldDef{
+  --           name = "m2",
+  --           number = 1,
+  --           type = upb.TYPE_MESSAGE,
+  --           subdef_name = ".M2"
+  --         },
+  --       }
+  --     },
+  --     upb.MessageDef{full_name = "M2"}
+  --   }
+  upb.build_defs = function(defs)
+    upb.SymbolTable(defs)
+    -- Lua 5.2 puts unpack in the table library.
+    return (unpack or table.unpack)(defs)
+  end
+
+  local ipairs_iter = function(array, last_index)
+    local next_index = last_index + 1
+    if next_index > #array then
+      return nil
+    end
+    return next_index, array[next_index]
+  end
+
+  -- For iterating over the indexes and values of a upb.Array.
+  --
+  -- for i, val in upb.ipairs(array) do
+  --   -- ...
+  -- end
+  upb.ipairs = function(array)
+    return ipairs_iter, array, 0
+  end
+
+  local set_named = function(obj, init)
+    for k, v in pairs(init) do
+      local func = obj["set_" .. k]
+      if not func then
+        error("Cannot set member: " .. k)
+      end
+      func(obj, v)
+    end
+  end
+
+  -- Capture references to the functions we're wrapping.
+  local RealFieldDef = upb.FieldDef
+  local RealEnumDef = upb.EnumDef
+  local RealMessageDef = upb.MessageDef
+  local RealSymbolTable = upb.SymbolTable
+
+  -- FieldDef constructor; a wrapper around the real constructor that can
+  -- set initial properties.
+  --
+  -- User can specify initialization values like so:
+  --   upb.FieldDef{label=upb.LABEL_REQUIRED, name="my_field", number=5,
+  --                type=upb.TYPE_INT32, default_value=12, type_name="Foo"}
+  upb.FieldDef = function(init)
+    local f = RealFieldDef()
+
+    if init then
+      -- Other members are often dependent on type, so set that first.
+      if init.type then
+        f:set_type(init.type)
+        init.type = nil
+      end
+
+      set_named(f, init)
+    end
+
+    return f
+  end
+
+
+  -- MessageDef constructor; a wrapper around the real constructor that can
+  -- set initial properties.
+  --
+  -- User can specify initialization values like so:
+  --   upb.MessageDef{full_name="MyMessage", extstart=8000, fields={...}}
+  upb.MessageDef = function(init)
+    local m = RealMessageDef()
+
+    if init then
+      for _, f in pairs(init.fields or {}) do
+        m:add(f)
+      end
+      init.fields = nil
+
+      set_named(m, init)
+    end
+
+    return m
+  end
+
+  -- EnumDef constructor; a wrapper around the real constructor that can
+  -- set initial properties.
+  --
+  -- User can specify initialization values like so:
+  --   upb.EnumDef{full_name="MyEnum",
+  --     values={
+  --       {"FOO_VALUE_1", 1},
+  --       {"FOO_VALUE_2", 2}
+  --     }
+  --   }
+  upb.EnumDef = function(init)
+    local e = RealEnumDef()
+
+    if init then
+      for _, val in pairs(init.values or {}) do
+        e:add(val[1], val[2])
+      end
+      init.values = nil
+
+      set_named(e, init)
+    end
+
+    return e
+  end
+
+  -- SymbolTable constructor; a wrapper around the real constructor that can
+  -- add an initial set of defs.
+  upb.SymbolTable = function(defs)
+    local s = RealSymbolTable()
+
+    if defs then
+      s:add(defs)
+    end
+
+    return s
+  end
+end