Simplify and improve the sygus parser (#2266)

Currently, there is code duplication for parsing constants in sygus grammars, e.g.:
https://github.com/CVC4/CVC4/blob/master/src/parser/smt2/Smt2.g#L1048
https://github.com/CVC4/CVC4/blob/master/src/parser/smt2/Smt2.g#L2304

This PR removes this duplication by introducing a new ANTLR grammar "termAtomic" in Smt2.g.

As a result of this PR, we now parse sygus grammars with any constant we otherwise parse. This addresses known issues where CVC4 rejects grammars with floating point constants.

It also removes some unnecessary code for converting builtin kinds to their total versions.

This is work towards #2197.  We still do not support sygus grammars with non-trivial *composite* terms, such as applications of indexed function symbols.

1 files changed, 47 insertions, 75 deletions

diff --git a/src/parser/smt2/Smt2.g b/src/parser/smt2/Smt2.g
index c512ee1da..9bcac27ca 100644
--- a/src/parser/smt2/Smt2.g
+++ b/src/parser/smt2/Smt2.g
@@ -921,30 +921,17 @@ sygusGTerm[CVC4::SygusGTerm& sgt, std::string& fun]
   std::string name, name2;
   Kind k;
   Type t;
-  CVC4::DatatypeConstructor* ctor = NULL;
   std::string sname;
   std::vector< Expr > let_vars;
   bool readingLet = false;
   std::string s;
+  CVC4::Expr atomExpr;
 }
   : LPAREN_TOK
     //read operator
     ( builtinOp[k]{ 
         Debug("parser-sygus") << "Sygus grammar " << fun << " : builtin op : "
                               << name << std::endl;
-        // Since we enforce satisfaction completeness, immediately convert to
-        // total version.
-        if( k==CVC4::kind::BITVECTOR_UDIV ){
-          k = CVC4::kind::BITVECTOR_UDIV_TOTAL;
-        }else if( k==CVC4::kind::BITVECTOR_UREM ){
-          k = CVC4::kind::BITVECTOR_UREM_TOTAL;
-        }else if( k==CVC4::kind::DIVISION ){
-          k = CVC4::kind::DIVISION_TOTAL;
-        }else if( k==CVC4::kind::INTS_DIVISION ){
-          k = CVC4::kind::INTS_DIVISION_TOTAL;
-        }else if( k==CVC4::kind::INTS_MODULUS ){
-          k = CVC4::kind::INTS_MODULUS_TOTAL;
-        }
         sgt.d_name = kind::kindToString(k);
         sgt.d_gterm_type = SygusGTerm::gterm_op;
         sgt.d_expr = EXPR_MANAGER->operatorOf(k);
@@ -992,17 +979,6 @@ sygusGTerm[CVC4::SygusGTerm& sgt, std::string& fun]
           Debug("parser-sygus") << "Sygus grammar " << fun << " : builtin op : "
                                 << name << std::endl;
           k = PARSER_STATE->getOperatorKind(name);
-          if( k==CVC4::kind::BITVECTOR_UDIV ){
-            k = CVC4::kind::BITVECTOR_UDIV_TOTAL;
-          }else if( k==CVC4::kind::BITVECTOR_UREM ){
-            k = CVC4::kind::BITVECTOR_UREM_TOTAL;
-          }else if( k==CVC4::kind::DIVISION ){
-            k = CVC4::kind::DIVISION_TOTAL;
-          }else if( k==CVC4::kind::INTS_DIVISION ){
-            k = CVC4::kind::INTS_DIVISION_TOTAL;
-          }else if( k==CVC4::kind::INTS_MODULUS ){
-            k = CVC4::kind::INTS_MODULUS_TOTAL;
-          }
           sgt.d_name = kind::kindToString(k);
           sgt.d_gterm_type = SygusGTerm::gterm_op;
           sgt.d_expr = EXPR_MANAGER->operatorOf(k);
@@ -1044,38 +1020,13 @@ sygusGTerm[CVC4::SygusGTerm& sgt, std::string& fun]
         PARSER_STATE->popScope();
       }
     }
-  | INTEGER_LITERAL
-    { Debug("parser-sygus") << "Sygus grammar " << fun << " : integer literal "
-                            << AntlrInput::tokenText($INTEGER_LITERAL)
-                            << std::endl;
-      sgt.d_expr = MK_CONST(Rational(AntlrInput::tokenText($INTEGER_LITERAL)));
-      sgt.d_name = AntlrInput::tokenText($INTEGER_LITERAL);
-      sgt.d_gterm_type = SygusGTerm::gterm_op;
-    }
-  | HEX_LITERAL
-    { Debug("parser-sygus") << "Sygus grammar " << fun << " : hex literal "
-                            << AntlrInput::tokenText($HEX_LITERAL) << std::endl;
-      assert( AntlrInput::tokenText($HEX_LITERAL).find("#x") == 0 );
-      std::string hexString = AntlrInput::tokenTextSubstr($HEX_LITERAL, 2);
-      sgt.d_expr = MK_CONST( BitVector(hexString, 16) );
-      sgt.d_name = AntlrInput::tokenText($HEX_LITERAL);
-      sgt.d_gterm_type = SygusGTerm::gterm_op;
-    }
-  | BINARY_LITERAL
-    { Debug("parser-sygus") << "Sygus grammar " << fun << " : binary literal "
-                            << AntlrInput::tokenText($BINARY_LITERAL)
-                            << std::endl;
-      assert( AntlrInput::tokenText($BINARY_LITERAL).find("#b") == 0 );
-      std::string binString = AntlrInput::tokenTextSubstr($BINARY_LITERAL, 2);
-      sgt.d_expr = MK_CONST( BitVector(binString, 2) );
-      sgt.d_name = AntlrInput::tokenText($BINARY_LITERAL);
-      sgt.d_gterm_type = SygusGTerm::gterm_op;
-    }
-  | str[s,false]
-    { Debug("parser-sygus") << "Sygus grammar " << fun << " : string literal \""
-                            << s << "\"" << std::endl;
-      sgt.d_expr = MK_CONST( ::CVC4::String(s, true) );
-      sgt.d_name = s;
+    | termAtomic[atomExpr] {
+      Debug("parser-sygus") << "Sygus grammar " << fun << " : atomic "
+                            << "expression " << atomExpr << std::endl;
+      std::stringstream ss;
+      ss << atomExpr;
+      sgt.d_expr = atomExpr;
+      sgt.d_name = ss.str();
       sgt.d_gterm_type = SygusGTerm::gterm_op;
     }
   | symbol[name,CHECK_NONE,SYM_VARIABLE]
@@ -1779,8 +1730,9 @@ term[CVC4::Expr& expr, CVC4::Expr& expr2]
   ;
 
 /**
- * Matches a term.
- * @return the expression representing the formula
+ * Matches a non-variable term.
+ * @return the expression expr representing the term or formula, and expr2, an
+ * optional annotation for expr (for instance, for attributed expressions).
  */
 termNonVariable[CVC4::Expr& expr, CVC4::Expr& expr2]
 @init {
@@ -1797,13 +1749,13 @@ termNonVariable[CVC4::Expr& expr, CVC4::Expr& expr2]
   std::vector<Expr> patconds;
   std::unordered_set<std::string> names;
   std::vector< std::pair<std::string, Expr> > binders;
-  Type type, type2;
-  std::string s;
   bool isBuiltinOperator = false;
   bool isOverloadedFunction = false;
   bool readVariable = false;
   int match_vindex = -1;
   std::vector<Type> match_ptypes;
+  Type type;
+  Type type2;
 }
   : /* a built-in operator application */
     LPAREN_TOK builtinOp[kind] termList[args,expr] RPAREN_TOK
@@ -2278,8 +2230,38 @@ termNonVariable[CVC4::Expr& expr, CVC4::Expr& expr2]
       PARSER_STATE->popScope();
       expr = MK_EXPR( CVC4::kind::LAMBDA, args );
     }
+
+  | LPAREN_TOK TUPLE_CONST_TOK termList[args,expr] RPAREN_TOK
+  {
+    std::vector<Type> types;
+    for (std::vector<Expr>::const_iterator i = args.begin(); i != args.end();
+         ++i)
+    {
+      types.push_back((*i).getType());
+    }
+    DatatypeType t = EXPR_MANAGER->mkTupleType(types);
+    const Datatype& dt = t.getDatatype();
+    args.insert(args.begin(), dt[0].getConstructor());
+    expr = MK_EXPR(kind::APPLY_CONSTRUCTOR, args);
+  }
+  | /* an atomic term (a term with no subterms) */
+    termAtomic[expr]
+  ;
+
+
+/**
+ * Matches an atomic term (a term with no subterms).
+ * @return the expression expr representing the term or formula.
+ */
+termAtomic[CVC4::Expr& expr]
+@init {
+  std::vector<Expr> args;
+  Type type;
+  Type type2;
+  std::string s;
+}
     /* constants */
-  | INTEGER_LITERAL
+  : INTEGER_LITERAL
     { expr = MK_CONST( AntlrInput::tokenToInteger($INTEGER_LITERAL) ); }
 
   | DECIMAL_LITERAL
@@ -2384,18 +2366,7 @@ termNonVariable[CVC4::Expr& expr, CVC4::Expr& expr2]
     { //booleanType is placeholder here since we don't have type info without type annotation
       expr = EXPR_MANAGER->mkNullaryOperator(EXPR_MANAGER->booleanType(), kind::SEP_NIL); }
     // NOTE: Theory constants go here
-
-  | LPAREN_TOK TUPLE_CONST_TOK termList[args,expr] RPAREN_TOK
-    { std::vector<Type> types;
-      for(std::vector<Expr>::const_iterator i = args.begin(); i != args.end(); ++i) {
-        types.push_back((*i).getType());
-      }
-      DatatypeType t = EXPR_MANAGER->mkTupleType(types);
-      const Datatype& dt = t.getDatatype();
-      args.insert(args.begin(), dt[0].getConstructor());
-      expr = MK_EXPR(kind::APPLY_CONSTRUCTOR, args);
-    }
-  
+    
   | TUPLE_CONST_TOK
     { std::vector<Type> types;
       DatatypeType t = EXPR_MANAGER->mkTupleType(types);
@@ -2403,8 +2374,9 @@ termNonVariable[CVC4::Expr& expr, CVC4::Expr& expr2]
       args.insert(args.begin(), dt[0].getConstructor());
       expr = MK_EXPR(kind::APPLY_CONSTRUCTOR, args);
     }
+    
   ;
-
+  
 /**
  * Read attribute
  */