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| author | Andrew Reynolds <andrew.j.reynolds@gmail.com> | 2020-06-11 21:25:07 -0500 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-06-11 21:25:07 -0500 |
| commit | 4d547e52d3f2b54a0af7270d2b653d2cb24edb57 (patch) | |
| tree | 3e73d2c1adbe9798bbcc316831d34821adac54d8 | |
| parent | ad87bbc615944514fcfcb3689768aab60a9cc9d6 (diff) | |
Add rewrite for str.replace_re. (#4601)
This was discovered due to a proof checking abnormality, where the checker surprisingly succeeded in proving that the reduced form for a str.replace_re was equivalent for 2 different sets of skolems after rewriting.
| -rw-r--r-- | src/theory/strings/rewrites.cpp | 1 | ||||
| -rw-r--r-- | src/theory/strings/rewrites.h | 1 | ||||
| -rw-r--r-- | src/theory/strings/sequences_rewriter.cpp | 7 |
3 files changed, 9 insertions, 0 deletions
diff --git a/src/theory/strings/rewrites.cpp b/src/theory/strings/rewrites.cpp index 5f3c83869..b67315935 100644 --- a/src/theory/strings/rewrites.cpp +++ b/src/theory/strings/rewrites.cpp @@ -113,6 +113,7 @@ const char* toString(Rewrite r) case Rewrite::RPL_X_Y_X_SIMP: return "RPL_X_Y_X_SIMP"; case Rewrite::REPLACE_RE_EVAL: return "REPLACE_RE_EVAL"; case Rewrite::REPLACE_RE_ALL_EVAL: return "REPLACE_RE_ALL_EVAL"; + case Rewrite::REPLACE_RE_EMP_RE: return "REPLACE_RE_EMP_RE"; case Rewrite::SPLIT_EQ: return "SPLIT_EQ"; case Rewrite::SPLIT_EQ_STRIP_L: return "SPLIT_EQ_STRIP_L"; case Rewrite::SPLIT_EQ_STRIP_R: return "SPLIT_EQ_STRIP_R"; diff --git a/src/theory/strings/rewrites.h b/src/theory/strings/rewrites.h index 62350c403..3b23e1e39 100644 --- a/src/theory/strings/rewrites.h +++ b/src/theory/strings/rewrites.h @@ -118,6 +118,7 @@ enum class Rewrite : uint32_t RPL_X_Y_X_SIMP, REPLACE_RE_EVAL, REPLACE_RE_ALL_EVAL, + REPLACE_RE_EMP_RE, SPLIT_EQ, SPLIT_EQ_STRIP_L, SPLIT_EQ_STRIP_R, diff --git a/src/theory/strings/sequences_rewriter.cpp b/src/theory/strings/sequences_rewriter.cpp index 3c40062f5..befe52574 100644 --- a/src/theory/strings/sequences_rewriter.cpp +++ b/src/theory/strings/sequences_rewriter.cpp @@ -2948,6 +2948,13 @@ Node SequencesRewriter::rewriteReplaceRe(Node node) return returnRewrite(node, x, Rewrite::REPLACE_RE_EVAL); } } + // str.replace_re( x, y, z ) ---> z ++ x if "" in y ---> true + String emptyStr(""); + if (RegExpEntail::testConstStringInRegExp(emptyStr, 0, y)) + { + Node ret = nm->mkNode(STRING_CONCAT, z, x); + return returnRewrite(node, ret, Rewrite::REPLACE_RE_EMP_RE); + } return node; } |