virtual expr check_type(expr const & m, abstract_type_context & ctx, bool infer_only) const {
check_macro(m);
expr given_type = macro_arg(m, 0);
if (!infer_only) {
ctx.check(given_type, infer_only);
expr inferred_type = ctx.check(macro_arg(m, 1), infer_only);
if (!ctx.is_def_eq(inferred_type, given_type)) {
throw_kernel_exception(ctx.env(), m, [=](formatter const & fmt) {
return format("type mismatch at term") + pp_type_mismatch(fmt, macro_arg(m, 1), inferred_type, given_type);
});
}
}
return given_type;
}
virtual expr check_type(expr const & m, abstract_type_context & ctx, bool infer_only) const {
check_macro(m);
environment const & env = ctx.env();
expr s = macro_arg(m, 0);
expr s_t = ctx.whnf(ctx.check(s, infer_only));
buffer<expr> I_args;
expr const & I = get_app_args(s_t, I_args);
if (!is_constant(I)) {
// remark: this is not an issue since this macro should not be used during elaboration.
throw_kernel_exception(env, sstream() << "projection macros do not support arbitrary terms "
<< "containing metavariables yet (solution: use trust-level 0)", m);
}
if (length(const_levels(I)) != length(m_ps))
throw_kernel_exception(env, sstream() << "invalid projection application '" << m_proj_name
<< "', incorrect number of universe parameters", m);
expr t = instantiate_univ_params(m_type, m_ps, const_levels(I));
I_args.push_back(s);
return instantiate_rev(t, I_args.size(), I_args.data());
}
virtual optional<expr> expand(expr const & m, abstract_type_context & ctx) const {
check_macro(m);
expr const & s = macro_arg(m, 0);
expr new_s = ctx.whnf(s);
buffer<expr> c_args;
expr const & c = get_app_args(new_s, c_args);
if (is_constant(c) && const_name(c) == m_constructor_name && m_idx < c_args.size()) {
return some_expr(c_args[m_idx]);
} else {
// expand into recursor
expr s_type = ctx.whnf(ctx.infer(s));
buffer<expr> args;
expr const & I = get_app_args(s_type, args);
if (!is_constant(I) || length(m_ps) != length(const_levels(I)))
return none_expr();
expr r = instantiate_univ_params(m_val, m_ps, const_levels(I));
args.push_back(new_s);
return some(instantiate_rev(r, args.size(), args.data()));
}
}
