void forward_branch_extension::index_expr(expr const & e) {
// TODO(dhs): index the target when it gets updated
if (auto head_idx = to_head_index(e)) {
m_index.insert(head_index(e), e);
}
switch (e.kind()) {
case expr_kind::Var:
lean_unreachable(); // LCOV_EXCL_LINE
case expr_kind::Local:
case expr_kind::Meta:
case expr_kind::Sort:
case expr_kind::Constant:
case expr_kind::Macro: // TODO(dhs): do I unfold macros?
break;
case expr_kind::Lambda:
case expr_kind::Pi:
// TODO(dhs): confirm that I only index quantified-free hypotheses
break;
case expr_kind::Let:
// Let-expressions must be unfolded before invoking this method
lean_unreachable();
case expr_kind::App:
index_expr(app_fn(e));
index_expr(app_arg(e));
break;
}
}
optional<head_index> get_head_index(unsigned num, transition const * ts, expr const & a) {
if (is_simple(num, ts)) {
expr n = expand_pp_pattern(num, ts, a);
if (!is_var(n))
return some(head_index(n));
}
return optional<head_index>();
}
static optional<head_index> to_head_index(expr type) {
// TODO(dhs): we will want to filter this set,
// because some constants are treated specially by this module
// (e.g. [eq] and [not])
expr const & f = get_app_fn(type);
if (is_constant(f) || is_local(f))
return optional<head_index>(head_index(f));
else
return optional<head_index>();
}
action_result grinder_intro_action() {
grinder_branch_extension & ext = get_ext();
state & s = curr_state();
expr const & target = s.get_target();
expr const & f = get_app_fn(target);
if (!is_constant(f))
return action_result::failed();
list<gexpr> const * lemmas = ext.m_intro_lemmas.find(head_index(f));
if (!lemmas)
return action_result::failed();
return backward_cut_action(*lemmas);
}
void SnakeObject::draw(const DrawContext& gc) {
_program_p->begin();
_program_p->arg("snakeSkin",_tex_p->index());
_tex_p->activate();
glBegin(GL_QUADS);
auto index = tail_index();
int previous_point = index;
--index;
for (; index != head_index(); --index) {
const auto &p = points()[previous_point];
const auto &q = points()[index];
const auto &t0 = p.bottomLeft().c_elems();
const auto &t1 = p.topMiddle().c_elems();
const auto &t2 = p.bottomRight().c_elems();
const auto &u0 = q.bottomLeft().c_elems();
const auto &u1 = q.topMiddle().c_elems();
const auto &u2 = q.bottomRight().c_elems();
// quad on side 0
glTexCoord2d(previous_point,0);
glVertex3fv(t0);
glTexCoord2d(index,0);
glVertex3fv(u0);
glTexCoord2d(index,0.5);
glVertex3fv(u1);
glTexCoord2d(previous_point,0.5);
glVertex3fv(t1);
// quad on other side
glTexCoord2d(previous_point,1.0);
glVertex3fv(t2);
glTexCoord2d(previous_point,0.5);
glVertex3fv(t1);
glTexCoord2d(index,0.5);
glVertex3fv(u1);
glTexCoord2d(index,1.0);
glVertex3fv(u2);
previous_point = index;
}
glEnd();
_program_p->end();
}
