From 46349d90291dc755225863552eb19beb1038c505 Mon Sep 17 00:00:00 2001
From: graehl <graehl@ec762483-ff6d-05da-a07a-a48fb63a330f>
Date: Fri, 13 Aug 2010 03:31:04 +0000
Subject: named enum

git-svn-id: https://ws10smt.googlecode.com/svn/trunk@537 ec762483-ff6d-05da-a07a-a48fb63a330f
---
 utils/named_enum.h | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100755 utils/named_enum.h

diff --git a/utils/named_enum.h b/utils/named_enum.h
new file mode 100755
index 00000000..b459b4a9
--- /dev/null
+++ b/utils/named_enum.h
@@ -0,0 +1,121 @@
+#ifndef NAMED_ENUM_H
+#define NAMED_ENUM_H
+
+#ifndef NAMED_ENUM_USE_OPTIONAL
+# define NAMED_ENUM_USE_OPTIONAL 1
+#endif
+
+//TODO: efficiency - supply map type (e.g. std::map or tr1::unordered_map) for string->int (int->string already fast w/ switch) - then implement iterators that don't assume contiguous ids.
+//TODO: hidden (can't convert string->id, but can do reverse) sentinel values.  XX (hidden) and XY (can convert to)
+//TODO: bitfield "A|B" strings - note: slightly complicates int->string, as well.
+//TODO: option for case-insensitive compare (ctype tolower?)
+
+/* named enum (string<->int).  note: inefficient linear search for string->int
+
+in e.h:
+
+#include "named_enum.h"
+#define SOME_ENUM(X,t) \
+    X(t,FirstValue,) \
+    X(t,SecondValue,) \
+    X(t,SomeOtherValue,=50) \
+    X(t,OneMoreValue,=100) \
+#define SOME_ENUM_TYPE MyEnum
+
+DECLARE_NAMED_ENUM(SOME_ENUM)
+
+in e.cc:
+
+DEFINE_NAMED_ENUM(SOME_ENUM)
+
+(or DEFINE_NAMED_ENUM_T(MyEnum,SOME_ENUM) )
+
+#include "e.h"
+
+elsewhere:
+
+#include "e.h"
+MyEnum e=GetMyEnum("FirstValue");
+string s=GetName(e);
+assert(s=="FirstValue");
+string usage=MyEnumNames("\n");
+
+ */
+
+#include <stdexcept>
+#include <sstream>
+#if NAMED_ENUM_USE_OPTIONAL
+# include <boost/optional.hpp>
+#endif
+#include "utoa.h"
+
+inline void throw_enum_error(std::string const& enumtype,std::string const& msg) {
+  throw std::runtime_error(enumtype+": "+msg);
+}
+#if NAMED_ENUM_USE_OPTIONAL
+#define NAMED_ENUM_OPTIONAL(x) x
+#else
+#define NAMED_ENUM_OPTIONAL(x)
+#endif
+
+// expansion macro for enum value definition
+#define NAMED_ENUM_VALUE(t,name,assign) name assign,
+
+// expansion macro for enum to string conversion
+#define NAMED_ENUM_CASE(t,name,assign) case name: return #name;
+
+// expansion macro for enum to string conversion
+#define NAMED_ENUM_STRCMP(t,name,assign) if (!std::strcmp(str,#name)) return name;
+
+// expansion macro for enum to optional conversion
+#define NAMED_ENUM_STRCMP_OPTIONAL(t,name,assign) if (!std::strcmp(str,#name)) return boost::optional<t>(name);
+
+#define NAMED_ENUM_APPEND_USAGE(t,name,assign) o << #name <<sp; sp=sep;
+
+/// declare the access function and define enum values
+#define DECLARE_NAMED_ENUM_T(DEF,EnumType)                    \
+  typedef enum  { \
+    DEF(NAMED_ENUM_VALUE,EnumType)                            \
+  } EnumType; \
+  const char *GetName(EnumType dummy); \
+  EnumType Get ## EnumType (const char *string); \
+  inline EnumType Get ## EnumType (std::string const& s) { return Get ## EnumType (s.c_str()); }   \
+  std::string EnumType ## Names (char const* sep=","); \
+  NAMED_ENUM_OPTIONAL(boost::optional<EnumType> Get ## EnumType ## Optional (const char *string);  inline boost::optional<EnumType> Get ## EnumType ## Optional (std::string const& s) { return Get ## EnumType ## Optional (s.c_str()); })
+
+/// define the access function names
+#define DEFINE_NAMED_ENUM_T(DEF,EnumType)       \
+   const char *GetName(EnumType value) \
+  { \
+    switch(value) \
+    { \
+      DEF(NAMED_ENUM_CASE,EnumType) \
+      default: \
+        throw_enum_error(#EnumType,"Illegal enum value (no name defined) "+itos((int)value));   \
+return ""; /* handle input error */             \
+    } \
+  } \
+   EnumType Get ## EnumType (const char *str) \
+  { \
+    DEF(NAMED_ENUM_STRCMP,EnumType)                                              \
+      throw_enum_error(#EnumType,"Couldn't convert '"+std::string(str)+"' - legal names: "+EnumType ## Names(" ")); \
+    return (EnumType)0; /* handle input error */    \
+  } \
+   std::string EnumType ## Names(char const* sep) {             \
+    std::ostringstream o; \
+    char const* sp=""; \
+    DEF(NAMED_ENUM_APPEND_USAGE,EnumType)        \
+    return o.str(); \
+    } \
+   NAMED_ENUM_OPTIONAL(boost::optional<EnumType> Get ## EnumType ## Optional (const char *str) { DEF(NAMED_ENUM_STRCMP_OPTIONAL,EnumType) return boost::optional<EnumType>(); })
+
+#undef _TYPE
+#define DECLARE_NAMED_ENUM_T2(x,y) DECLARE_NAMED_ENUM_T(x,y)
+#define DEFINE_NAMED_ENUM_T2(x,y) DEFINE_NAMED_ENUM_T(x,y)
+#define DECLARE_NAMED_ENUM(ENUM_DEF) DECLARE_NAMED_ENUM_T2(ENUM_DEF,ENUM_DEF ## _TYPE)
+#define DEFINE_NAMED_ENUM(ENUM_DEF) DEFINE_NAMED_ENUM_T2(ENUM_DEF,ENUM_DEF ## _TYPE)
+#define MAKE_NAMED_ENUM(ENUM_DEF) \
+  DECLARE_NAMED_ENUM(ENUM_DEF)    \
+  DEFINE_NAMED_ENUM(ENUM_DEF)
+
+#endif
-- 
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