src/expr/declaration_scope.h

   1 /*********************                                                        */
   2 /*! \file declaration_scope.h
   3  ** \verbatim
   4  ** Original author: cconway
   5  ** Major contributors: none
   6  ** Minor contributors (to current version): dejan, mdeters
   7  ** This file is part of the CVC4 prototype.
   8  ** Copyright (c) 2009, 2010  The Analysis of Computer Systems Group (ACSys)
   9  ** Courant Institute of Mathematical Sciences
  10  ** New York University
  11  ** See the file COPYING in the top-level source directory for licensing
  12  ** information.\endverbatim
  13  **
  14  ** \brief Convenience class for scoping variable and type declarations.
  15  **
  16  ** Convenience class for scoping variable and type declarations.
  17  **/
  18
  19 #include "cvc4_public.h"
  20
  21 #ifndef __CVC4__DECLARATION_SCOPE_H
  22 #define __CVC4__DECLARATION_SCOPE_H
  23
  24 #include <vector>
  25 #include <utility>
  26 #include <ext/hash_map>
  27
  28 #include "expr/expr.h"
  29 #include "util/hash.h"
  30
  31 #include "context/cdset_forward.h"
  32 #include "context/cdmap_forward.h"
  33
  34 namespace CVC4 {
  35
  36 class Type;
  37
  38 namespace context {
  39   class Context;
  40 }/* CVC4::context namespace */
  41
  42 class CVC4_PUBLIC ScopeException : public Exception {
  43 };/* class ScopeException */
  44
  45 /**
  46  * A convenience class for handling scoped declarations. Implements the usual
  47  * nested scoping rules for declarations, with separate bindings for expressions
  48  * and types.
  49  */
  50 class CVC4_PUBLIC DeclarationScope {
  51   /** The context manager for the scope maps. */
  52   context::Context *d_context;
  53
  54   /** A map for expressions. */
  55   context::CDMap<std::string, Expr, StringHashFunction> *d_exprMap;
  56
  57   /** A map for types. */
  58   context::CDMap<std::string, std::pair<std::vector<Type>, Type>, StringHashFunction> *d_typeMap;
  59
  60   /** A set of defined functions. */
  61   context::CDSet<Expr, ExprHashFunction> *d_functions;
  62
  63 public:
  64   /** Create a declaration scope. */
  65   DeclarationScope();
  66
  67   /** Destroy a declaration scope. */
  68   ~DeclarationScope();
  69
  70   /**
  71    * Bind an expression to a name in the current scope level.  If
  72    * <code>name</code> is already bound to an expression in the current
  73    * level, then the binding is replaced. If <code>name</code> is bound
  74    * in a previous level, then the binding is "covered" by this one
  75    * until the current scope is popped.
  76    *
  77    * @param name an identifier
  78    * @param obj the expression to bind to <code>name</code>
  79    */
  80   void bind(const std::string& name, Expr obj) throw(AssertionException);
  81
  82   /**
  83    * Bind a function body to a name in the current scope.  If
  84    * <code>name</code> is already bound to an expression in the current
  85    * level, then the binding is replaced. If <code>name</code> is bound
  86    * in a previous level, then the binding is "covered" by this one
  87    * until the current scope is popped.  Same as bind() but registers
  88    * this as a function (so that isBoundDefinedFunction() returns true).
  89    *
  90    * @param name an identifier
  91    * @param obj the expression to bind to <code>name</code>
  92    */
  93   void bindDefinedFunction(const std::string& name, Expr obj) throw(AssertionException);
  94
  95   /**
  96    * Bind a type to a name in the current scope.  If <code>name</code>
  97    * is already bound to a type in the current level, then the binding
  98    * is replaced. If <code>name</code> is bound in a previous level,
  99    * then the binding is "covered" by this one until the current scope
 100    * is popped.
 101    *
 102    * @param name an identifier
 103    * @param t the type to bind to <code>name</code>
 104    */
 105   void bindType(const std::string& name, Type t) throw();
 106
 107   /**
 108    * Bind a type to a name in the current scope.  If <code>name</code>
 109    * is already bound to a type or type constructor in the current
 110    * level, then the binding is replaced. If <code>name</code> is
 111    * bound in a previous level, then the binding is "covered" by this
 112    * one until the current scope is popped.
 113    *
 114    * @param name an identifier
 115    * @param params the parameters to the type
 116    * @param t the type to bind to <code>name</code>
 117    */
 118   void bindType(const std::string& name,
 119                 const std::vector<Type>& params,
 120                 Type t) throw();
 121
 122   /**
 123    * Check whether a name is bound to an expression with either bind()
 124    * or bindDefinedFunction().
 125    *
 126    * @param name the identifier to check.
 127    * @returns true iff name is bound in the current scope.
 128    */
 129   bool isBound(const std::string& name) const throw();
 130
 131   /**
 132    * Check whether a name was bound to a function with bindDefinedFunction().
 133    */
 134   bool isBoundDefinedFunction(const std::string& name) const throw();
 135
 136   /**
 137    * Check whether a name is bound to a type (or type constructor).
 138    *
 139    * @param name the identifier to check.
 140    * @returns true iff name is bound to a type in the current scope.
 141    */
 142   bool isBoundType(const std::string& name) const throw();
 143
 144   /**
 145    * Lookup a bound expression.
 146    *
 147    * @param name the identifier to lookup
 148    * @returns the expression bound to <code>name</code> in the current scope.
 149    */
 150   Expr lookup(const std::string& name) const throw(AssertionException);
 151
 152   /**
 153    * Lookup a bound type.
 154    *
 155    * @param name the type identifier to lookup
 156    * @returns the type bound to <code>name</code> in the current scope.
 157    */
 158   Type lookupType(const std::string& name) const throw(AssertionException);
 159
 160   /**
 161    * Lookup a bound parameterized type.
 162    *
 163    * @param name the type-constructor identifier to lookup
 164    * @param params the types to use to parameterize the type
 165    * @returns the type bound to <code>name(<i>params</i>)</code> in
 166    * the current scope.
 167    */
 168   Type lookupType(const std::string& name,
 169                   const std::vector<Type>& params) const throw(AssertionException);
 170
 171   /**
 172    * Pop a scope level. Deletes all bindings since the last call to
 173    * <code>pushScope</code>. Calls to <code>pushScope</code> and
 174    * <code>popScope</code> must be "properly nested." I.e., a call to
 175    * <code>popScope</code> is only legal if the number of prior calls to
 176    * <code>pushScope</code> on this <code>DeclarationScope</code> is strictly
 177    * greater than then number of prior calls to <code>popScope</code>. */
 178   void popScope() throw(ScopeException);
 179
 180   /** Push a scope level. */
 181   void pushScope() throw();
 182
 183 };/* class DeclarationScope */
 184
 185 }/* CVC4 namespace */
 186
 187 #endif /* __CVC4__DECLARATION_SCOPE_H */