53667dd602
Fixes #1363 After error recovery has been implemented in the elaborator, a few assumptions made in the type context are not valid anymore since we may be recovering from errors, and the local and metavariable contexts may be invalid. I used the approach used in the class environment. - find* methods return optional<...> - get* methods throw exception for unknown elements Remarks: I preserved code patterns such as optional<local_decl> d = lctx.find_local_decl(...) lean_assert(d) and did not convert them into local_decl d = lctx.get_local_decl(...) Reason: the intention is clear that the local must be defined there. If it is not we should analyze the problem and decide whether we should throw an exception or not. However, I converted code patterns such as local_decl d = *lctx.find_local_decl(...) into local_decl d = lctx.get_local_decl(...) Disclaimer: this change fixes issue #1363, but it may obfuscate other bugs.
56 lines
1.9 KiB
C++
56 lines
1.9 KiB
C++
/*
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Copyright (c) 2016 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Leonardo de Moura
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*/
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#include "library/trace.h"
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#include "library/vm/vm_list.h"
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#include "library/tactic/tactic_state.h"
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namespace lean {
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expr revert(environment const & env, options const & opts, metavar_context & mctx, expr const & mvar, buffer<expr> & locals) {
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optional<metavar_decl> g = mctx.find_metavar_decl(mvar);
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lean_assert(g);
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type_context ctx = mk_type_context_for(env, opts, mctx, g->get_context(), transparency_mode::All);
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expr val = ctx.revert(locals, mvar);
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expr new_g = get_app_fn(val);
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mctx = ctx.mctx();
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return new_g;
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}
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tactic_state revert(buffer<expr> & locals, tactic_state const & s) {
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lean_assert(s.goals());
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metavar_context mctx = s.mctx();
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expr new_g = revert(s.env(), s.get_options(), mctx, head(s.goals()), locals);
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return set_mctx_goals(s, mctx, cons(new_g, tail(s.goals())));
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}
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vm_obj revert(list<expr> const & ls, tactic_state const & s) {
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optional<metavar_decl> g = s.get_main_goal_decl();
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if (!g) return mk_no_goals_exception(s);
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local_context lctx = g->get_context();
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buffer<expr> locals;
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for (expr const & l : ls) {
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if (lctx.find_local_decl(l)) {
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locals.push_back(l);
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} else {
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return mk_tactic_exception(sstream() << "revert tactic failed, unknown '"
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<< local_pp_name(l) << "' hypothesis", s);
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}
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}
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tactic_state new_s = revert(locals, s);
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return mk_tactic_success(mk_vm_nat(locals.size()), new_s);
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}
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vm_obj tactic_revert_lst(vm_obj const & ns, vm_obj const & s) {
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return revert(to_list_expr(ns), to_tactic_state(s));
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}
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void initialize_revert_tactic() {
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DECLARE_VM_BUILTIN(name({"tactic", "revert_lst"}), tactic_revert_lst);
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}
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void finalize_revert_tactic() {
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}
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}
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