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refactor(library/tactic): remove 'null' tactic, and operator bool tactics

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Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2013-12-08 15:00:16 -08:00
parent a4afdfeace
commit 8add5571f1
3 changed files with 26 additions and 27 deletions
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38
src/frontends/lean/parser.cpp
View file

@ -176,11 +176,11 @@ class parser::imp {
};
template<typename F>
void using_script(F && f) {
m_script_state->apply([&](lua_State * L) {
typename std::result_of<F(lua_State * L)>::type using_script(F && f) {
return m_script_state->apply([&](lua_State * L) {
set_io_state set1(L, m_frontend.get_state());
set_environment set2(L, m_frontend.get_environment());
f(L);
return f(L);
});
}
@ -1142,12 +1142,11 @@ class parser::imp {
*/
tactic parse_tactic_expr() {
auto p = pos();
tactic t;
if (curr() == scanner::token::ScriptBlock) {
parse_script_expr();
using_script([&](lua_State * L) {
return using_script([&](lua_State * L) {
try {
t = to_tactic_ext(L, -1);
return to_tactic_ext(L, -1);
} catch (...) {
throw parser_error("invalid script-block, it must return a tactic", p);
}
@ -1157,25 +1156,26 @@ class parser::imp {
expr pr = parse_expr();
check_rparen_next("invalid apply command, ')' expected");
expr pr_type = m_type_inferer(pr);
t = ::lean::apply_tactic(pr, pr_type);
return ::lean::apply_tactic(pr, pr_type);
} else {
name n = check_identifier_next("invalid apply command, identifier, '(' expr ')', or 'script-block' expected");
optional<object> o = m_frontend.find_object(n);
if (o && (o->is_theorem() || o->is_axiom())) {
t = ::lean::apply_tactic(n);
return ::lean::apply_tactic(n);
} else {
using_script([&](lua_State * L) {
return using_script([&](lua_State * L) {
lua_getglobal(L, n.to_string().c_str());
try {
t = to_tactic_ext(L, -1);
tactic t = to_tactic_ext(L, -1);
lua_pop(L, 1);
return t;
} catch (...) {
lua_pop(L, 1);
throw parser_error(sstream() << "unknown tactic '" << n << "'", p);
}
lua_pop(L, 1);
});
}
}
return t;
}
/** \brief Parse <tt>'show' expr 'by' tactic</tt> */
@ -1186,7 +1186,7 @@ class parser::imp {
check_next(scanner::token::By, "invalid 'show _ by _' expression, 'by' expected");
tactic tac = parse_tactic_expr();
expr r = mk_placeholder(some_expr(t));
m_tactic_hints[r] = tac;
m_tactic_hints.insert(mk_pair(r, tac));
return save(r, p);
}
@ -1196,7 +1196,7 @@ class parser::imp {
next();
tactic tac = parse_tactic_expr();
expr r = mk_placeholder();
m_tactic_hints[r] = tac;
m_tactic_hints.insert(mk_pair(r, tac));
return save(r, p);
}
@ -1513,13 +1513,13 @@ class parser::imp {
If the metavariable is not associated with any hint, then return the
null tactic. The method also returns the position of the hint.
*/
std::pair<tactic, pos_info> get_tactic_tactic_for(expr const & mvar) {
std::pair<optional<tactic>, pos_info> get_tactic_for(expr const & mvar) {
expr placeholder = m_elaborator.get_original(mvar);
auto it = m_tactic_hints.find(placeholder);
if (it != m_tactic_hints.end()) {
return mk_pair(it->second, pos_of(placeholder, pos()));
return mk_pair(some_tactic(it->second), pos_of(placeholder, pos()));
} else {
return mk_pair(tactic(), pos_of(placeholder, pos()));
return mk_pair(none_tactic(), pos_of(placeholder, pos()));
}
}
@ -1559,10 +1559,10 @@ class parser::imp {
if (!m_type_inferer.is_proposition(mvar_type, mvar_ctx))
throw exception("failed to synthesize metavar, its type is not a proposition");
proof_state s = to_proof_state(m_frontend, mvar_ctx, mvar_type);
std::pair<tactic, pos_info> hint_and_pos = get_tactic_tactic_for(mvar);
std::pair<optional<tactic>, pos_info> hint_and_pos = get_tactic_for(mvar);
if (hint_and_pos.first) {
// metavariable has an associated tactic hint
s = apply_tactic(s, hint_and_pos.first, hint_and_pos.second).first;
s = apply_tactic(s, *(hint_and_pos.first), hint_and_pos.second).first;
menv.assign(mvar, mk_proof_for(s, hint_and_pos.second, mvar_ctx, mvar_type));
} else {
if (curr_is_period()) {

9
src/library/tactic/tactic.cpp
View file

@ -521,9 +521,8 @@ DECL_UDATA(tactic)
ORELSE(assumption_tactic(), conj_tactic())
*/
tactic to_tactic_ext(lua_State * L, int i) {
tactic t;
if (is_tactic(L, i)) {
t = to_tactic(L, i);
return to_tactic(L, i);
} else if (lua_isfunction(L, i)) {
try {
lua_pushvalue(L, i);
@ -532,17 +531,15 @@ tactic to_tactic_ext(lua_State * L, int i) {
throw_tactic_expected(i);
}
if (is_tactic(L, -1)) {
t = to_tactic(L, -1);
tactic t = to_tactic(L, -1);
lua_pop(L, 1);
return t;
} else {
throw_tactic_expected(i);
}
} else {
throw_tactic_expected(i);
}
if (!t)
throw exception(sstream() << "arg #" << i << " must be a nonnull tactic");
return t;
}
static void check_ios(io_state * ios) {

6
src/library/tactic/tactic.h
View file

@ -69,12 +69,10 @@ class tactic {
protected:
tactic_cell * m_ptr;
public:
tactic():m_ptr(nullptr) {}
explicit tactic(tactic_cell * ptr):m_ptr(ptr) { if (m_ptr) m_ptr->inc_ref(); }
tactic(tactic const & s):m_ptr(s.m_ptr) { if (m_ptr) m_ptr->inc_ref(); }
tactic(tactic && s):m_ptr(s.m_ptr) { s.m_ptr = nullptr; }
~tactic() { if (m_ptr) m_ptr->dec_ref(); }
explicit operator bool() const { return m_ptr != nullptr; }
friend void swap(tactic & a, tactic & b) { std::swap(a.m_ptr, b.m_ptr); }
tactic & operator=(tactic const & s);
tactic & operator=(tactic && s);
@ -88,6 +86,10 @@ public:
solve_result solve(environment const & env, io_state const & io, context const & ctx, expr const & t);
};
inline optional<tactic> none_tactic() { return optional<tactic>(); }
inline optional<tactic> some_tactic(tactic const & o) { return optional<tactic>(o); }
inline optional<tactic> some_tactic(tactic && o) { return optional<tactic>(std::forward<tactic>(o)); }
/**
\brief Create a tactic using the given functor.
The functor must contain the operator: