From cadde94017b235ef4c18b3164261be75be1dc626 Mon Sep 17 00:00:00 2001
From: Murphy Berzish <murphy.berzish@gmail.com>
Date: Mon, 7 Aug 2017 23:02:55 -0400
Subject: [PATCH] fix indentation and add support for re.allchar

---
 src/smt/theory_str.cpp | 70 ++++++++++++++++++++++++++----------------
 1 file changed, 44 insertions(+), 26 deletions(-)

diff --git a/src/smt/theory_str.cpp b/src/smt/theory_str.cpp
index b869abb0a..727e7e131 100644
--- a/src/smt/theory_str.cpp
+++ b/src/smt/theory_str.cpp
@@ -1685,6 +1685,8 @@ namespace smt {
             u.str.is_string(range1, range1val);
             u.str.is_string(range2, range2val);
             return zstring("[") + range1val + zstring("-") + range2val + zstring("]");
+        } else if (u.re.is_full(a_regex)) {
+            return zstring(".");
         } else {
             TRACE("str", tout << "BUG: unrecognized regex term " << mk_pp(regex, get_manager()) << std::endl;);
             UNREACHABLE(); return zstring("");
@@ -1794,6 +1796,13 @@ namespace smt {
             expr_ref finalAxiom(m.mk_iff(ex, rhs), m);
             SASSERT(finalAxiom);
             assert_axiom(finalAxiom);
+        } else if (u.re.is_full(regex)) {
+            // equivalent to regex "." operator, match any one character.
+            // we rewrite to expr IFF len(str) == 1
+            expr_ref rhs(ctx.mk_eq_atom(mk_strlen(str), m_autil.mk_numeral(rational::one(), true)), m);
+            expr_ref finalAxiom(m.mk_iff(ex, rhs), m);
+            SASSERT(finalAxiom);
+            assert_axiom(finalAxiom);
         } else {
             TRACE("str", tout << "ERROR: unknown regex expression " << mk_pp(regex, m) << "!" << std::endl;);
             NOT_IMPLEMENTED_YET();
@@ -6190,32 +6199,32 @@ namespace smt {
             zstring str;
             if (u.str.is_string(arg_str, str)) {
                 if (str.length() == 0) {
-		  // transitioning on the empty string is handled specially
-		  TRACE("str", tout << "empty string epsilon-move " << start << " --> " << end << std::endl;);
-		  make_epsilon_move(start, end);
-	        } else {
-                  TRACE("str", tout << "build NFA for '" << str << "'" << "\n";);
-                  /*
-                   * For an n-character string, we make (n-1) intermediate states,
-                   * labelled i_(0) through i_(n-2).
-                   * Then we construct the following transitions:
-                   * start --str[0]--> i_(0) --str[1]--> i_(1) --...--> i_(n-2) --str[n-1]--> final
-                   */
-                  unsigned last = start;
-                  for (int i = 0; i <= ((int)str.length()) - 2; ++i) {
-		    unsigned i_state = next_id();
-		    make_transition(last, str[i], i_state);
-		    TRACE("str", tout << "string transition " << last << "--" << str[i] << "--> " << i_state << "\n";);
-		    last = i_state;
-                  }
-                  make_transition(last, str[(str.length() - 1)], end);
-                  TRACE("str", tout << "string transition " << last << "--" << str[(str.length() - 1)] << "--> " << end << "\n";);
-		}
-	    } else { // ! u.str.is_string(arg_str, str)
-              TRACE("str", tout << "invalid string constant in Str2Reg" << std::endl;);
-              m_valid = false;
-              return;
-	    }
+                    // transitioning on the empty string is handled specially
+                    TRACE("str", tout << "empty string epsilon-move " << start << " --> " << end << std::endl;);
+                    make_epsilon_move(start, end);
+                } else {
+                    TRACE("str", tout << "build NFA for '" << str << "'" << "\n";);
+                    /*
+                     * For an n-character string, we make (n-1) intermediate states,
+                     * labelled i_(0) through i_(n-2).
+                     * Then we construct the following transitions:
+                     * start --str[0]--> i_(0) --str[1]--> i_(1) --...--> i_(n-2) --str[n-1]--> final
+                     */
+                    unsigned last = start;
+                    for (int i = 0; i <= ((int)str.length()) - 2; ++i) {
+                        unsigned i_state = next_id();
+                        make_transition(last, str[i], i_state);
+                        TRACE("str", tout << "string transition " << last << "--" << str[i] << "--> " << i_state << "\n";);
+                        last = i_state;
+                    }
+                    make_transition(last, str[(str.length() - 1)], end);
+                    TRACE("str", tout << "string transition " << last << "--" << str[(str.length() - 1)] << "--> " << end << "\n";);
+                }
+            } else { // ! u.str.is_string(arg_str, str)
+                TRACE("str", tout << "invalid string constant in Str2Reg" << std::endl;);
+                m_valid = false;
+                return;
+            }
         } else if (u.re.is_concat(e)){
             app * a = to_app(e);
             expr * re1 = a->get_arg(0);
@@ -6284,6 +6293,15 @@ namespace smt {
             }
 
             TRACE("str", tout << "range NFA: start = " << start << ", end = " << end << std::endl;);
+        } else if (u.re.is_full(e)) {
+            // equivalent to "transition on each character in the alphabet"
+
+            // TODO this hard-codes something about theory_str's char set here
+
+            for (unsigned i = 1; i <= 255; ++i) {
+                char ch = (char)i;
+                make_transition(start, ch, end);
+            }
         } else {
             TRACE("str", tout << "invalid regular expression" << std::endl;);
             m_valid = false;