mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2026-06-29 20:08:52 +00:00
Code Activity

Revert is_concat changes, add ZIPT URL, implement snode/sgraph operations and tests

Browse source 
- Revert is_str_concat/is_re_concat to original form (PR #8820 review)
- Add ZIPT URL (https://github.com/CEisenhofer/ZIPT) to euf_sgraph.h
- Add snode::at() for token indexing and collect_tokens() for enumeration
- Add sgraph factory methods: mk_var, mk_char, mk_empty, mk_concat
- Add sgraph drop operations: drop_first, drop_last, drop_left, drop_right
- Add sgraph substitution: subst(snode*, snode*, snode*)
- Add Brzozowski derivative via seq_rewriter::mk_derivative
- Add minterm computation from regex predicates
- Add 7 new unit tests covering all new operations with complex concats

Co-authored-by: NikolajBjorner <56730610+NikolajBjorner@users.noreply.github.com>
This commit is contained in:
copilot-swe-agent[bot] 2026-03-02 19:28:32 +00:00
parent 40b99311e3
commit 150f1fe2ea
5 changed files with 501 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

26
src/ast/euf/euf_sgraph.h
View file

@ -10,6 +10,7 @@ Abstract:
Sequence/string graph layer
Encapsulates string and regex expressions for the string solver.
Implements the string graph layer from ZIPT (https://github.com/CEisenhofer/ZIPT).
The sgraph maps Z3 sequence/regex AST expressions to snode structures
organized as binary concatenation trees with metadata, and owns an
egraph with a seq_plugin for congruence closure.
@ -59,6 +60,7 @@ Author:
#include "util/statistics.h"
#include "ast/ast.h"
#include "ast/seq_decl_plugin.h"
#include "ast/rewriter/seq_rewriter.h"
#include "ast/euf/euf_snode.h"
#include "ast/euf/euf_egraph.h"
@ -79,10 +81,12 @@ namespace euf {
ast_manager& m;
seq_util m_seq;
seq_rewriter m_rewriter;
egraph m_egraph;
region m_region;
snode_vector m_nodes;
expr_ref_vector m_exprs; // pin expressions
sort_ref m_str_sort; // cached string sort
unsigned_vector m_scopes;
unsigned m_num_scopes = 0;
stats m_stats;
@ -93,6 +97,7 @@ namespace euf {
snode* mk_snode(expr* e, snode_kind k, unsigned num_args, snode* const* args);
snode_kind classify(expr* e) const;
void compute_metadata(snode* n);
void collect_re_predicates(snode* re, expr_ref_vector& preds);
public:
sgraph(ast_manager& m);
@ -112,6 +117,27 @@ namespace euf {
// register expression in both sgraph and egraph
enode* mk_enode(expr* e);
// factory methods for creating snodes with corresponding expressions
snode* mk_var(symbol const& name);
snode* mk_char(unsigned ch);
snode* mk_empty();
snode* mk_concat(snode* a, snode* b);
// drop operations: remove tokens from the front/back of a concat tree
snode* drop_first(snode* n);
snode* drop_last(snode* n);
snode* drop_left(snode* n, unsigned count);
snode* drop_right(snode* n, unsigned count);
// substitution: replace all occurrences of var in n by replacement
snode* subst(snode* n, snode* var, snode* replacement);
// Brzozowski derivative of regex re with respect to element elem
snode* brzozowski_deriv(snode* re, snode* elem);
// compute minterms (character class partition) from a regex
void compute_minterms(snode* re, snode_vector& minterms);
// scope management for backtracking
void push();
void pop(unsigned num_scopes);