// ast.ast            see license.txt for copyright and terms of use
// ast definition for an ast definition

verbatim {
  #include "str.h"         // string

  // this signals to ast.hand.cc that ast.ast.cc is nonempty,
  // so none of the bootstrap code in ast.hand.cc should be used
  #define GENERATED_AST_PRESENT
}

// the entire specification
class ASTSpecFile (ASTList<ToplevelForm> forms);

class ToplevelForm {
  // code to be copied verbatim into the generated .h file
  -> TF_verbatim(string code);

  // code to be copied verbatim into the generated .cc file
  -> TF_impl_verbatim(string code);

  // a superclass, and a list of subclasses ("constructors")
  -> TF_class(ASTClass super,
              ASTList<ASTClass> ctors) {
       public bool hasChildren() const { return ctors.isNotEmpty(); };
     }
   
  // a generic option: first word specifies the kind of option, and
  // additional words (if any) are arguments
  -> TF_option(string name, ASTList<string> args);
  
  // generic custom/verbatim code
  -> TF_custom(CustomCode cust);

  // enumeration (at one point I had support for explicit enumerator
  // values, but decided that if the user wants that, they should put
  // the enum in a 'verbatim' section instead)
  -> TF_enum(string name, ASTList<string> enumerators);
}

// a definition of a grammar terminal or nonterminal
class ASTClass (string name,
                ASTList<CtorArg> args,
                ASTList<CtorArg> lastArgs,    // only for nonterminal
                ASTList<BaseClass> bases,
                ASTList<Annotation> decls) {
  // the name of the enum constant denoting this ctor, as distinguished
  // from its sibling ctors
  public string classKindName() const;
}

verbatim {
  // specifies what kind of userdecl this is; pub/priv/prot are uninterpreted
  // class members with the associated access control; ctor and dtor are
  // code to be inserted into the ctor or dtor, respectively
  enum AccessCtl {
    AC_PUBLIC,      // access
    AC_PRIVATE,     //   control
    AC_PROTECTED,   //     keywords
    AC_CTOR,        // insert into ctor
    AC_DTOR,        // insert into dtor
    AC_PUREVIRT,    // declare pure virtual in superclass, and impl in subclass
    NUM_ACCESSCTLS
  };

  // map the enum value to a string like "public"
  string toString(AccessCtl acc);      // defined in ast.cc
}

// an access control keyword with optional modifier list
class AccessMod(AccessCtl acc, ASTList<string> mods) {
  // true if the given modifier is present
  public bool hasMod(char const *mod) const;
  // true if the given modifier prefix is present as a prefix of a modifier
  public bool hasModPrefix(char const *mod) const;
  // get the suffix after the given prefix of the (first) modifier it matches
  public string getModSuffixFromPrefix(char const *mod) const;
}

// additional user annotations
class Annotation {
  // verbatim declarations, plus an access qualifier, to be
  // copied into the a class declaration; also has an optional
  // initializer (might be "")
  -> UserDecl (AccessMod amod, string code, string init) {
       public AccessCtl access() const { return amod->acc; };
     }

  // verbatim code to be inserted somewhere; exactly where depends
  // on the qualifier string
  -> CustomCode (string qualifier, string code) {
       // keep track of whether it gets used
       public bool used;  ctor used=false;
     }
}

// something that has to be passed to create a constructor
class CtorArg (bool isOwner, string type, string name, string defaultValue);

// designate a class that one of the ASTClasses should inherit; for
// AST subclasses, this inheritance is in addition to inheriting the
// corresponding AST superclass
class BaseClass (AccessCtl access, string name);


// ------------------- extra implementation helpers ------------------
impl_verbatim {

#include "strutil.h"      // stringToupper

string toString(AccessCtl acc)
{
  char const *arr[] = {
    "public",
    "private",
    "protected",
    "ctor",
    "dtor",
    "pure_virtual"
  };
  STATIC_ASSERT(TABLESIZE(arr) == NUM_ACCESSCTLS);
  xassert((unsigned)acc < NUM_ACCESSCTLS);
  return string(arr[acc]);
}

string ASTClass::classKindName() const
{
  string ret = stringToupper(name);
  if (ret == name) {
    // this simplemindedly avoids collisions with itself, and I think
    // it even avoids collisions with other classes, since if they would
    // collide with this, they'd collide with themselves too, and hence
    // get an extra "KIND_" prepended..
    ret &= "KIND_";
  }
  return ret;
}

bool AccessMod::hasMod(char const *mod) const
{
  FOREACH_ASTLIST(string, mods, iter) {
    if (iter.data()->equals(mod)) {
      return true;
    }
  }
  return false;      // not found
}

bool AccessMod::hasModPrefix(char const *mod) const
{
  string mod0(mod);
  FOREACH_ASTLIST(string, mods, iter) {
    rostring i = *iter.data();
    if (prefixEquals(i, mod0)) {
      return true;
    }
  }
  return false;      // not found
}

string AccessMod::getModSuffixFromPrefix(char const *mod) const
{
  string mod0(mod);
  string ret;
  bool found = false;
  FOREACH_ASTLIST(string, mods, iter) {
    rostring s = *iter.data();
    if (prefixEquals(s, mod0)) {
      if (found) {
        xfailure(stringc << "two modifiers with this prefix found " << mod);
      }
      int len = strlen(mod);
      ret = s.substring(len, s.length()-len);
      found = true;
    }
  }
  if (!found) {
    xfailure(stringc << "no such prefix found " << mod);
  }
  return ret;
}

} // end impl_verbatim