diff options
author | Andres Noetzli <andres.noetzli@gmail.com> | 2019-02-05 09:08:19 -0800 |
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committer | Andres Noetzli <andres.noetzli@gmail.com> | 2019-02-05 09:08:19 -0800 |
commit | d1e312cfe865bd7c167dff473f508f739d5ddc3b (patch) | |
tree | b2ec78178e0892224ca11c6a57585909ed4293ca | |
parent | ac1d170fa6c287614ffcadc5e27f136cee593664 (diff) |
Make stripConstantEndpoints() less aggressive
`stripConstantEndpoints({ "A" }, { "A". (int.to.str n) }, {}, {}, 0)`
was cutting off "A" because it is a non-digit. This is wrong, however,
because `(int.to.str n)` can return the empty string. This commit
makes `stripConstantEndpoints()` less aggressive by not using
`str.to.int` terms to cut off non-digits anymore.
-rw-r--r-- | src/theory/strings/theory_strings_rewriter.cpp | 20 | ||||
-rw-r--r-- | test/unit/theory/theory_strings_rewriter_white.h | 29 |
2 files changed, 28 insertions, 21 deletions
diff --git a/src/theory/strings/theory_strings_rewriter.cpp b/src/theory/strings/theory_strings_rewriter.cpp index 8d9d6a230..cbb298c5f 100644 --- a/src/theory/strings/theory_strings_rewriter.cpp +++ b/src/theory/strings/theory_strings_rewriter.cpp @@ -3683,26 +3683,6 @@ bool TheoryStringsRewriter::stripConstantEndpoints(std::vector<Node>& n1, overlap = s.size() - ret; } } - else if (n2[index1].getKind() == kind::STRING_ITOS) - { - const std::vector<unsigned>& svec = s.getVec(); - // can remove up to the first occurrence of a digit - unsigned svsize = svec.size(); - for (unsigned i = 0; i < svsize; i++) - { - unsigned sindex = r == 0 ? i : (svsize - 1) - i; - if (String::isDigit(svec[sindex])) - { - break; - } - else if (sss.empty()) // only if not substr - { - // e.g. str.contains( str.++( "a", x ), int.to.str(y) ) --> - // str.contains( x, int.to.str(y) ) - overlap--; - } - } - } else { // inconclusive diff --git a/test/unit/theory/theory_strings_rewriter_white.h b/test/unit/theory/theory_strings_rewriter_white.h index 6eb022eea..5b4846a12 100644 --- a/test/unit/theory/theory_strings_rewriter_white.h +++ b/test/unit/theory/theory_strings_rewriter_white.h @@ -1224,15 +1224,30 @@ class TheoryStringsRewriterWhite : public CxxTest::TestSuite d_nm->mkNode(kind::STRING_CONCAT, x, b)); sameNormalForm(eq, f); } + + { + // (= (str.++ "A" (int.to.str n)) "A") -/-> false + Node eq = d_nm->mkNode( + kind::EQUAL, d_nm->mkNode(kind::STRING_CONCAT, a, d_nm->mkNode(kind::STRING_ITOS, n)), a); + differentNormalForms(eq, f); + } } void testStripConstantEndpoints() { + TypeNode intType = d_nm->integerType(); + TypeNode strType = d_nm->stringType(); + Node empty = d_nm->mkConst(::CVC4::String("")); Node a = d_nm->mkConst(::CVC4::String("A")); + Node ab = d_nm->mkConst(::CVC4::String("AB")); + Node cd = d_nm->mkConst(::CVC4::String("CD")); + Node x = d_nm->mkVar("x", strType); + Node y = d_nm->mkVar("y", strType); + Node n = d_nm->mkVar("n", intType); { - // stripConstantEndpoints({ "" }, { "a" }, {}, {}, 0) ---> false + // stripConstantEndpoints({ "" }, { "A" }, {}, {}, 0) ---> false std::vector<Node> n1 = {empty}; std::vector<Node> n2 = {a}; std::vector<Node> nb; @@ -1241,6 +1256,18 @@ class TheoryStringsRewriterWhite : public CxxTest::TestSuite TheoryStringsRewriter::stripConstantEndpoints(n1, n2, nb, ne, 0); TS_ASSERT(!res); } + + { + // stripConstantEndpoints({ "A" }, { "A". (int.to.str n) }, {}, {}, 0) + // ---> false + std::vector<Node> n1 = {a}; + std::vector<Node> n2 = {a, d_nm->mkNode(kind::STRING_ITOS, n)}; + std::vector<Node> nb; + std::vector<Node> ne; + bool res = + TheoryStringsRewriter::stripConstantEndpoints(n1, n2, nb, ne, 0); + TS_ASSERT(!res); + } } void testRewriteMembership() |