lean4-htt/src/frontends/lean/inductive_cmds.cpp

792 lines
33 KiB
C++

/*
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Daniel Selsam, Leonardo de Moura
*/
#include <algorithm>
#include <string>
#include "runtime/sstream.h"
#include "util/name_map.h"
#include "util/fresh_name.h"
#include "util/sexpr/option_declarations.h"
#include "kernel/replace_fn.h"
#include "kernel/for_each_fn.h"
#include "kernel/find_fn.h"
#include "kernel/instantiate.h"
#include "kernel/abstract.h"
#include "kernel/inductive/inductive.h"
#include "library/locals.h"
#include "library/attribute_manager.h"
#include "library/deep_copy.h"
#include "library/placeholder.h"
#include "library/aliases.h"
#include "library/protected.h"
#include "library/explicit.h"
#include "library/reducible.h"
#include "library/class.h"
#include "library/trace.h"
#include "library/type_context.h"
#include "library/documentation.h"
#include "library/constants.h"
#include "library/normalize.h"
#include "library/inductive_compiler/add_decl.h"
#include "library/tactic/tactic_evaluator.h"
#include "frontends/lean/decl_cmds.h"
#include "frontends/lean/decl_util.h"
#include "frontends/lean/util.h"
#include "frontends/lean/elaborator.h"
#include "frontends/lean/parser.h"
#include "frontends/lean/tokens.h"
#include "frontends/lean/type_util.h"
#include "frontends/lean/inductive_cmds.h"
namespace lean {
static name * g_new_inductive = nullptr;
struct single_inductive_decl {
decl_attributes m_attrs;
expr m_expr;
buffer<expr> m_intros;
};
struct mutual_inductive_decl {
buffer<name> m_lp_names;
buffer<expr> m_params;
buffer<single_inductive_decl> m_decls;
};
static level mk_succn(level const & l, unsigned offset) {
level result = l;
for (unsigned i = 0; i < offset; ++i)
result = mk_succ(result);
return result;
}
static void convert_params_to_kernel(elaborator & elab, buffer<expr> const & lctx_params, buffer<expr> & kernel_params) {
for (unsigned i = 0; i < lctx_params.size(); ++i) {
expr new_type = replace_locals(elab.infer_type(lctx_params[i]), i, lctx_params.data(), kernel_params.data());
kernel_params.push_back(update_local(lctx_params[i], new_type));
}
}
static void replace_params(buffer<expr> const & params, buffer<expr> const & new_params, buffer<expr> const & inds, buffer<expr> const & new_inds,
buffer<expr> const & intro_rules, buffer<expr> & new_intro_rules) {
for (expr const & ir : intro_rules) {
expr new_type = replace_locals(local_type(ir), params, new_params);
new_type = replace_locals(new_type, inds, new_inds);
new_intro_rules.push_back(update_local(ir, new_type));
}
}
static level subtract_from_max_core(level const & l, unsigned offset) {
if (is_max(l)) {
return mk_max(subtract_from_max_core(max_lhs(l), offset), subtract_from_max_core(max_rhs(l), offset));
} else {
auto lvl_offset = to_offset(l);
if (lvl_offset.second < offset)
return lvl_offset.first;
else
return mk_succn(lvl_offset.first, lvl_offset.second - offset);
}
}
static level subtract_from_max(level const & l, unsigned offset) {
return normalize(subtract_from_max_core(l, offset));
}
class inductive_cmd_fn {
parser & m_p;
environment m_env;
cmd_meta m_meta_info;
buffer<decl_attributes> m_mut_attrs;
type_context_old m_ctx;
buffer<name> m_lp_names;
pos_info m_pos;
name_map<implicit_infer_kind> m_implicit_infer_map;
bool m_explicit_levels; // true if the user is providing explicit universe levels
level m_u_meta;
level m_u_param;
unsigned m_u_param_offset;
bool m_infer_result_universe{false};
[[ noreturn ]] void throw_error(char const * error_msg) const { throw parser_error(error_msg, m_pos); }
[[ noreturn ]] void throw_error(sstream const & strm) const { throw parser_error(strm, m_pos); }
bool use_new_inductive() const {
return m_p.get_options().get_bool(*g_new_inductive, false);
}
implicit_infer_kind get_implicit_infer_kind(name const & n) {
if (auto it = m_implicit_infer_map.find(n))
return *it;
else
return implicit_infer_kind::Implicit;
}
name mk_rec_name(name const & n) {
return ::lean::inductive::get_elim_name(n);
}
/** \brief Return true if eliminator/recursor can eliminate into any universe */
bool has_general_eliminator(name const & d_name) {
constant_info d = m_env.get(d_name);
constant_info r = m_env.get(mk_rec_name(d_name));
return d.get_num_univ_params() != r.get_num_univ_params();
}
void remove_non_parameters(buffer<expr> & params) {
unsigned j = 0;
for (unsigned i = 0; i < params.size(); i++) {
expr const & param = params[i];
if (m_p.is_local_decl_user_name(param) &&
!m_p.is_local_variable_user_name(local_pp_name(param))) {
expr const * klocal = m_p.get_local(local_pp_name(param));
lean_assert(klocal);
params[j] = *klocal;
j++;
}
}
params.shrink(j);
}
void collect_univ_params_ignoring_locals_core(level const & l, name_set & r) {
for_each(l, [&](level const & l) {
if (!has_param(l))
return false;
if (is_param(l) && !is_placeholder(l))
r.insert(param_id(l));
return true;
});
}
name_set collect_univ_params_ignoring_locals(expr const & e, name_set const & ls) {
if (!has_param_univ(e)) {
return ls;
} else {
name_set r = ls;
for_each(e, [&](expr const & e, unsigned) {
if (!has_param_univ(e)) {
return false;
} else if (is_sort(e)) {
collect_univ_params_core(sort_level(e), r);
} else if (is_constant(e)) {
for (auto const & l : const_levels(e))
collect_univ_params_core(l, r);
} else if (is_local(e)) {
return false;
}
return true;
});
return r;
}
}
bool has_explicit_level(buffer<buffer<expr> > const & intro_rules) {
for (buffer<expr> const & irs : intro_rules) {
for (expr const & ir : irs) {
name_set ls = collect_univ_params_ignoring_locals(local_type(ir), name_set());
if (!ls.empty()) {
lean_trace(name({"inductive", "lp_names"}), tout() << "explicit universe in '" << local_name(ir) << "': " << local_type(ir) << "\n";);
return true;
}
}
}
return false;
}
/** \brief Add aliases for the inductive datatype, introduction and elimination rules */
void add_aliases(buffer<expr> const & params, buffer<expr> const & inds, buffer<buffer<expr> > const & intro_rules) {
buffer<expr> params_only(params);
remove_non_parameters(params_only);
// Create aliases/local refs
levels ctx_levels = collect_local_nonvar_levels(m_p, names(m_lp_names));
for (expr const & ind : inds) {
name d_name = local_name(ind);
name d_short_name(d_name.get_string());
m_env = add_alias(m_p, m_env, false, d_name, ctx_levels, params_only);
name rec_name = mk_rec_name(d_name);
levels rec_ctx_levels = ctx_levels;
if (ctx_levels && has_general_eliminator(d_name))
rec_ctx_levels = levels(mk_level_placeholder(), rec_ctx_levels);
m_env = add_alias(m_p, m_env, true, rec_name, rec_ctx_levels, params_only);
m_env = add_protected(m_env, rec_name);
}
for (buffer<expr> const & irs : intro_rules) {
for (expr const & ir : irs) {
name ir_name = local_name(ir);
m_env = add_alias(m_p, m_env, true, ir_name, ctx_levels, params_only);
}
}
}
level replace_u(level const & l, level const & rlvl) {
return replace(l, [&](level const & l) {
if (l == m_u_param) return some_level(rlvl);
else return none_level();
});
}
expr replace_u(expr const & type, level const & rlvl) {
return replace(type, [&](expr const & e) {
if (is_sort(e)) {
return some_expr(update_sort(e, replace_u(sort_level(e), rlvl)));
} else if (is_constant(e)) {
return some_expr(update_constant(e, map(const_levels(e),
[&](level const & l) { return replace_u(l, rlvl); })));
} else {
return none_expr();
}
});
}
/** \brief Create a local constant based on the given binding */
expr mk_local_for(expr const & b) {
return copy_pos(b, mk_local(m_p.next_name(), binding_name(b), binding_domain(b), binding_info(b)));
}
/* \brief Add \c lvl to \c r_lvls (if it is not already there).
If the level contains the result level, it must be a `max`, in which case we accumulate the
other max arguments. Otherwise, we do nothing for now. If it is a nested occurrence,
then later on we confirm that the level of the argument unifies with the resultant level.
*/
void accumulate_level(level const & lvl, buffer<level> & r_lvls) {
if (lvl == mk_succn(m_u_param, m_u_param_offset)) {
return;
} else if (occurs(m_u_param, lvl)) {
if (is_max(lvl)) {
accumulate_level(max_lhs(lvl), r_lvls);
accumulate_level(max_rhs(lvl), r_lvls);
} else {
// We used to throw an exception here, but with nested inductive types,
// the argument level may still unify with the inferred resultant level.
}
} else {
if (std::find(r_lvls.begin(), r_lvls.end(), lvl) == r_lvls.end())
r_lvls.push_back(lvl);
}
}
/** \brief Accumulate the universe levels occurring in an introduction rule argument universe.
In general, the argument of an introduction rule has type
Pi (a_1 : A_1) (a_2 : A_1[a_1]) ..., B[a_1, a_2, ...]
The universe associated with it will be
imax(l_1, imax(l_2, ..., r))
where l_1 is the unvierse of A_1, l_2 of A_2, and r of B[a_1, ..., a_n].
The result placeholder m_u_param must only appear as r.
*/
void accumulate_levels(level const & lvl, buffer<level> & r_lvls) {
if (lvl == mk_succn(m_u_param, m_u_param_offset)) {
// ignore this is the auxiliary lvl
} else if (is_imax(lvl)) {
level lhs = imax_lhs(lvl);
level rhs = imax_rhs(lvl);
accumulate_level(lhs, r_lvls);
accumulate_levels(rhs, r_lvls);
} else {
accumulate_level(lvl, r_lvls);
}
}
/** \brief Traverse the introduction rule type and collect the universes where arguments reside in \c r_lvls.
This information is used to compute the resultant universe level for the inductive datatype declaration.
*/
void accumulate_levels(expr intro_type, buffer<level> & r_lvls) {
while (is_pi(intro_type)) {
level l = get_level(m_ctx, binding_domain(intro_type));
accumulate_levels(l, r_lvls);
intro_type = instantiate(binding_body(intro_type), mk_local_for(intro_type));
}
}
/** \brief Given a sequence of introduction rules (encoded as local constants), compute the resultant
universe for the inductive datatype declaration.
*/
level infer_resultant_universe(unsigned num_intro_rules, expr const * intro_rules) {
lean_assert(m_infer_result_universe);
buffer<level> r_lvls;
for (unsigned i = 0; i < num_intro_rules; i++) {
accumulate_levels(local_type(intro_rules[i]), r_lvls);
}
return mk_result_level(r_lvls);
}
/** \brief Return the universe level of the given type, if it is not a sort, then raise an exception. */
level get_datatype_result_level(expr d_type) {
d_type = m_ctx.relaxed_whnf(d_type);
type_context_old::tmp_locals locals(m_ctx);
while (is_pi(d_type)) {
d_type = instantiate(binding_body(d_type), locals.push_local_from_binding(d_type));
d_type = m_ctx.relaxed_whnf(d_type);
}
if (!is_sort(d_type))
throw_error(sstream() << "invalid inductive datatype, resultant type is not a sort");
return sort_level(d_type);
}
/** \brief Update the result sort of the given type */
expr update_result_sort(expr t, level const & l) {
t = m_ctx.whnf(t);
if (is_pi(t)) {
return update_binding(t, binding_domain(t), update_result_sort(binding_body(t), l));
} else if (is_sort(t)) {
return update_sort(t, l);
} else {
lean_unreachable();
}
}
void unify_nested_occurrences(type_context_old & ctx, expr const & ir_type, buffer<expr> const & inds, level const & resultant_level) {
expr ty = ir_type;
while (is_pi(ty)) {
expr arg_ty = binding_domain(ty);
for (expr const & ind : inds) {
if (static_cast<bool>(find(arg_ty, [&](expr const & e, unsigned) { return is_mlocal(e) && local_name(e) == local_name(ind); }))) {
level nested_level = get_level(ctx, arg_ty);
lean_trace(name({"inductive", "unify"}), tout() << nested_level << " =?= " << resultant_level << "\n";);
if (!ctx.is_def_eq(mk_sort(nested_level), mk_sort(resultant_level))) {
throw exception(sstream() << "nested occurrence '" << arg_ty << "' lives in universe '" << nested_level << "' but must live in resultant universe '" << resultant_level << "'");
}
}
}
expr local = ctx.push_local(binding_name(ty), arg_ty, binding_info(ty));
ty = instantiate(binding_body(ty), local);
}
}
void check_constant_resultant_universe(expr const & ir, level const & constant_resultant_level) {
type_context_old ctx(m_env);
expr ty = local_type(ir);
unsigned ir_arg = 0;
while (is_pi(ty)) {
ir_arg++;
expr arg_ty = binding_domain(ty);
level arg_level = get_level(ctx, arg_ty);
if (!(is_geq(constant_resultant_level, arg_level) || is_zero(constant_resultant_level))) {
throw exception(sstream() << "universe level of type_of(arg #" << ir_arg << ") "
<< "of '" << local_name(ir) << "' is too big for the corresponding inductive datatype");
}
expr local = ctx.push_local(binding_name(ty), arg_ty, binding_info(ty));
ty = instantiate(binding_body(ty), local);
}
}
void parse_intro_rules(bool has_params, expr const & ind, buffer<expr> & intro_rules, bool prepend_ns) {
// If the next token is not `|`, then the inductive type has no constructors
if (m_p.curr_is_token(get_bar_tk())) {
m_p.next();
while (true) {
m_pos = m_p.pos();
name ir_name = local_name(ind) + m_p.check_atomic_id_next("invalid introduction rule, atomic identifier expected");
if (prepend_ns)
ir_name = get_namespace(m_env) + ir_name;
parser::local_scope S(m_p);
buffer<expr> params;
implicit_infer_kind kind = implicit_infer_kind::Implicit;
m_p.parse_optional_binders(params, kind);
m_implicit_infer_map.insert(ir_name, kind);
for (expr const & param : params)
m_p.add_local(param);
expr ir_type;
if (has_params || m_p.curr_is_token(get_colon_tk())) {
m_p.check_token_next(get_colon_tk(), "invalid introduction rule, ':' expected");
ir_type = m_p.parse_expr();
} else {
ir_type = ind;
}
ir_type = Pi(params, ir_type, m_p);
intro_rules.push_back(mk_local(ir_name, ir_type));
lean_trace(name({"inductive", "parse"}), tout() << ir_name << " : " << ir_type << "\n";);
if (!m_p.curr_is_token(get_bar_tk()) && !m_p.curr_is_token(get_comma_tk()))
break;
m_p.next();
}
}
}
/** \brief Add a namespace for each inductive datatype */
void add_namespaces(buffer<expr> const & inds) {
for (expr const & ind : inds) {
m_env = add_namespace(m_env, local_name(ind));
}
}
/* Apply beta and zeta reduction */
expr normalize(expr const & e) {
type_context_old::transparency_scope scope(m_ctx, transparency_mode::None);
return ::lean::normalize(m_ctx, e);
}
void elaborate_inductive_decls(buffer<expr> const & params, buffer<expr> const & inds, buffer<buffer<expr> > const & intro_rules,
buffer<expr> & new_params, buffer<expr> & new_inds, buffer<buffer<expr> > & new_intro_rules) {
options opts = m_p.get_options();
bool recover_from_errors = true;
elaborator elab(m_env, opts, local_pp_name(inds[0]), metavar_context(), local_context(), recover_from_errors);
buffer<expr> params_no_inds;
for (expr const & p : params) {
if (!std::any_of(inds.begin(), inds.end(), [&](expr const & ind) { return local_name(ind) == local_name(p); }))
params_no_inds.push_back(p);
}
buffer<expr> elab_params;
elaborate_params(elab, params_no_inds, elab_params);
convert_params_to_kernel(elab, elab_params, new_params);
level result_level;
bool first = true;
for (expr const & ind : inds) {
expr new_ind_type = local_type(ind);
if (is_placeholder(new_ind_type))
new_ind_type = mk_sort(mk_level_placeholder());
new_ind_type = elab.elaborate(replace_locals(new_ind_type, params_no_inds, new_params));
new_ind_type = normalize(new_ind_type);
level l = get_datatype_result_level(new_ind_type);
if (is_mvar(l)) {
if (m_explicit_levels)
throw_error("resultant universe must be provided, when using explicit universe levels");
new_ind_type = update_result_sort(new_ind_type, m_u_meta);
m_infer_result_universe = true;
}
if (first) {
result_level = l;
first = false;
} else {
if (!is_mvar(l) && result_level != l) {
throw_error("mutually inductive types must live in the same universe");
}
}
new_inds.push_back(update_local(ind, new_ind_type));
}
for (buffer<expr> const & irs : intro_rules) {
new_intro_rules.emplace_back();
replace_params(params_no_inds, new_params, inds, new_inds, irs, new_intro_rules.back());
for (expr & new_ir : new_intro_rules.back()) {
expr new_ir_type = elab.elaborate(local_type(new_ir));
new_ir_type = normalize(new_ir_type);
new_ir = update_local(new_ir, new_ir_type);
lean_trace(name({"inductive", "infer_resultant"}), tout() << "[elaborated ir]: " << local_type(new_ir) << "\n";);
}
}
buffer<name> implicit_lp_names;
buffer<unsigned> offsets;
buffer<expr> all_exprs;
offsets.push_back(new_params.size());
all_exprs.append(new_params);
offsets.push_back(new_inds.size());
all_exprs.append(new_inds);
for (buffer<expr> & irs : new_intro_rules) {
offsets.push_back(irs.size());
all_exprs.append(irs);
}
bool u_meta_has_assignment = static_cast<bool>(elab.mctx().get_assignment(m_u_meta));
lean_trace(name({"inductive", "infer_resultant"}), tout() << "[has assignment]: " << u_meta_has_assignment << "\n";);
all_exprs.push_back(mk_sort(m_u_meta));
elab.finalize(all_exprs, implicit_lp_names, true, false);
level m_u_meta_assignment = sort_level(all_exprs.back());
all_exprs.pop_back();
pair<level, unsigned> m_u_meta_assignment_offset = to_offset(m_u_meta_assignment);
bool is_shifted_param = is_param(m_u_meta_assignment_offset.first);
bool is_constant = is_zero(m_u_meta_assignment_offset.first);
lean_trace(name({"inductive", "infer_resultant"}), tout() << "[assignment]: " << m_u_meta_assignment << "\n";);
if (!is_shifted_param && !is_constant) {
// resultant level tried to unify with something that is not a constant or a shifted level parameter
throw exception(sstream() << "resultant level unifies with complex level '" << m_u_meta_assignment << "', provide the universe levels explicitly");
}
lean_assert(is_shifted_param || is_constant);
for (name const & lp_name : implicit_lp_names) {
if (!(is_shifted_param && param_id(m_u_meta_assignment_offset.first) == lp_name))
m_lp_names.emplace_back(lp_name);
}
m_u_param = m_u_meta_assignment_offset.first;
m_u_param_offset = m_u_meta_assignment_offset.second;
m_env = elab.env();
new_params.clear();
new_inds.clear();
new_intro_rules.clear();
if (is_constant)
m_infer_result_universe = false;
level resultant_level;
level replacement_level;
if (m_infer_result_universe) {
level resultant_level_guess = infer_resultant_universe(all_exprs.size() - offsets[0] - offsets[1], all_exprs.data() + offsets[0] + offsets[1]);
lean_trace(name({"inductive", "infer_resultant"}), tout() << "[resultant_level_guess]: " << resultant_level_guess << "\n";);
replacement_level = subtract_from_max(resultant_level_guess, m_u_param_offset);
resultant_level = mk_succn(replacement_level, m_u_param_offset);
lean_trace(name({"inductive", "infer_resultant"}), tout() << "[resultant_level]: " << resultant_level << "\n";);
lean_trace(name({"inductive", "infer_resultant"}), tout() << "[replacement_level]: " << replacement_level << "\n";);
for (unsigned i = offsets[0]; i < offsets[0] + offsets[1]; ++i) {
expr ind_type = replace_u(local_type(all_exprs[i]), replacement_level);
new_inds.push_back(update_local(all_exprs[i], ind_type));
}
} else {
for (unsigned i = offsets[0]; i < offsets[0] + offsets[1]; ++i) {
new_inds.push_back(all_exprs[i]);
}
}
for (unsigned i = 0; i < offsets[0]; ++i) {
new_params.push_back(all_exprs[i]);
}
// We replace the inds appearing in the types of introduction rules with constants
buffer<expr> c_inds;
for (expr const & ind : inds) {
c_inds.push_back(mk_app(mk_constant(local_name(ind), param_names_to_levels(names(m_lp_names))), new_params));
}
unsigned offset = offsets[0] + offsets[1];
for (unsigned i = 2; i < offsets.size(); ++i) {
new_intro_rules.emplace_back();
for (unsigned j = 0; j < offsets[i]; ++j) {
expr new_ir = all_exprs[offset+j];
if (m_infer_result_universe) {
new_ir = update_local(new_ir, replace_u(local_type(new_ir), replacement_level));
unify_nested_occurrences(m_ctx, local_type(new_ir), inds, resultant_level);
} else if (is_constant) {
unify_nested_occurrences(m_ctx, local_type(new_ir), inds, m_u_meta_assignment);
}
new_ir = replace_locals(new_ir, offsets[1], all_exprs.data() + offsets[0], c_inds.data());
new_intro_rules.back().push_back(new_ir);
}
offset += offsets[i];
}
if (is_constant) {
for (unsigned ind_idx = 0; ind_idx < inds.size(); ++ind_idx) {
for (expr const & new_ir : new_intro_rules[ind_idx]) {
check_constant_resultant_universe(new_ir, m_u_meta_assignment);
}
}
}
for (expr const & e : all_exprs) {
lean_trace(name({"inductive", "finalize"}),
tout() << local_name(e) << " (" << local_pp_name(e) << ") : " << local_type(e) << "\n";);
}
}
expr parse_inductive(buffer<expr> & params, buffer<expr> & intro_rules) {
parser::local_scope scope(m_p);
m_pos = m_p.pos();
declaration_name_scope nscope;
expr ind = parse_single_header(m_p, nscope, m_lp_names, params);
m_explicit_levels = !m_lp_names.empty();
m_mut_attrs.push_back({});
ind = mk_local(get_namespace(m_p.env()) + local_name(ind), local_name(ind), local_type(ind), local_info(ind));
lean_trace(name({"inductive", "parse"}),
tout() << local_name(ind) << " : " << local_type(ind) << "\n";);
m_p.add_local(ind);
m_p.parse_local_notation_decl();
parse_intro_rules(!params.empty(), ind, intro_rules, false);
buffer<expr> ind_intro_rules;
ind_intro_rules.push_back(ind);
ind_intro_rules.append(intro_rules);
collect_implicit_locals(m_p, m_lp_names, params, ind_intro_rules);
for (expr const & e : params) {
lean_trace(name({"inductive", "params"}),
tout() << local_name(e) << " (" << local_pp_name(e) << ") : " << local_type(e) << "\n";);
}
return ind;
}
void parse_mutual_inductive(buffer<expr> & params, buffer<expr> & inds, buffer<buffer<expr> > & intro_rules) {
parser::local_scope scope(m_p);
buffer<expr> pre_inds;
parse_mutual_header(m_p, m_lp_names, pre_inds, params);
m_explicit_levels = !m_lp_names.empty();
m_p.parse_local_notation_decl();
for (expr const & pre_ind : pre_inds) {
m_pos = m_p.pos();
expr ind_type; decl_attributes attrs;
std::tie(ind_type, attrs) = parse_inner_header(m_p, local_pp_name(pre_ind));
check_attrs(attrs);
m_mut_attrs.push_back(attrs);
lean_trace(name({"inductive", "parse"}), tout() << local_name(pre_ind) << " : " << ind_type << "\n";);
intro_rules.emplace_back();
parse_intro_rules(!params.empty(), pre_ind, intro_rules.back(), true);
expr ind = mk_local(get_namespace(m_p.env()) + local_name(pre_ind), ind_type);
inds.push_back(ind);
}
for (buffer<expr> & irs : intro_rules) {
for (expr & ir : irs) {
ir = replace_locals(ir, pre_inds, inds);
}
}
buffer<expr> all_inds_intro_rules;
all_inds_intro_rules.append(inds);
for (buffer<expr> const & irs : intro_rules)
all_inds_intro_rules.append(irs);
collect_implicit_locals(m_p, m_lp_names, params, all_inds_intro_rules);
}
void check_attrs(decl_attributes const & attrs) const {
if (!attrs.ok_for_inductive_type())
throw_error("only attribute [class] accepted for inductive types");
}
void check_modifiers() const {
if (m_meta_info.m_modifiers.m_is_noncomputable)
throw_error("invalid 'noncomputable' modifier for inductive type");
if (m_meta_info.m_modifiers.m_is_private)
throw_error("invalid 'private' modifier for inductive type");
if (m_meta_info.m_modifiers.m_is_protected)
throw_error("invalid 'protected' modifier for inductive type");
}
public:
inductive_cmd_fn(parser & p, cmd_meta const & meta):
m_p(p), m_env(p.env()), m_meta_info(meta), m_ctx(p.env()) {
m_u_meta = m_ctx.mk_univ_metavar_decl();
check_attrs(m_meta_info.m_attrs);
check_modifiers();
}
void post_process(buffer<expr> const & new_params, buffer<expr> const & new_inds, buffer<buffer<expr> > const & new_intro_rules) {
add_aliases(new_params, new_inds, new_intro_rules);
add_namespaces(new_inds);
for (expr const & ind : new_inds) {
/* TODO(Leo): add support for doc-strings in mutual inductive definitions.
We are currently using the same doc string for all elements.
*/
if (m_meta_info.m_doc_string)
m_env = add_doc_string(m_env, local_name(ind), *m_meta_info.m_doc_string);
/* Apply attributes last so that they may access any information on the new decl */
m_env = m_meta_info.m_attrs.apply(m_env, m_p.ios(), local_name(ind));
}
lean_assert(new_inds.size() == m_mut_attrs.size());
for (unsigned i = 0; i < new_inds.size(); ++i)
m_env = m_mut_attrs[i].apply(m_env, m_p.ios(), local_name(new_inds[i]));
}
struct parse_result {
buffer<expr> m_params;
buffer<expr> m_inds;
buffer<buffer<expr> > m_intro_rules;
};
void parse(parse_result & result) {
buffer<expr> params;
buffer<expr> inds;
buffer<buffer<expr> > intro_rules;
if (m_meta_info.m_modifiers.m_is_mutual) {
parse_mutual_inductive(params, inds, intro_rules);
} else {
intro_rules.emplace_back();
inds.push_back(parse_inductive(params, intro_rules.back()));
}
if (!m_explicit_levels) {
m_explicit_levels = has_explicit_level(intro_rules);
}
elaborate_inductive_decls(params, inds, intro_rules, result.m_params, result.m_inds, result.m_intro_rules);
}
void add_inductive_decls(parse_result & r) {
unsigned num_params = r.m_params.size();
buffer<inductive_type> ind_types;
for (unsigned i = 0; i < r.m_inds.size(); i++) {
buffer<constructor> cnstrs;
for (expr const & intro : r.m_intro_rules[i]) {
implicit_infer_kind kind = get_implicit_infer_kind(local_name(intro));
expr type = Pi(r.m_params, local_type(intro));
type = infer_implicit_params(type, num_params, kind);
cnstrs.push_back(constructor(local_name(intro), type));
}
ind_types.push_back(inductive_type(local_name(r.m_inds[i]), Pi(r.m_params, local_type(r.m_inds[i])), constructors(cnstrs)));
}
m_env = m_env.add(mk_inductive_decl(names(m_lp_names), nat(num_params), inductive_types(ind_types), m_meta_info.m_modifiers.m_is_meta));
}
environment inductive_cmd() {
parse_result r;
parse(r);
if (use_new_inductive()) {
add_inductive_decls(r);
} else {
m_env = add_inductive_declaration(m_p.env(), m_p.get_options(), m_implicit_infer_map, m_lp_names, r.m_params,
r.m_inds, r.m_intro_rules, m_meta_info.m_modifiers.m_is_meta);
post_process(r.m_params, r.m_inds, r.m_intro_rules);
}
return m_env;
}
mutual_inductive_decl parse_and_elaborate() {
parse_result r;
parse(r);
buffer<single_inductive_decl> decls;
for (unsigned i = 0; i < r.m_inds.size(); i++) {
decls.push_back({m_mut_attrs[i], r.m_inds[i], r.m_intro_rules[i]});
}
return { m_lp_names, r.m_params, decls };
}
};
void parse_inductive_decl(parser & p, cmd_meta const & meta) {
auto pos = p.pos();
module::scope_pos_info scope_pos(pos);
inductive_cmd_fn(p, meta).parse_and_elaborate();
}
environment inductive_cmd(parser & p, cmd_meta const & meta) {
p.next();
auto pos = p.pos();
module::scope_pos_info scope_pos(pos);
return inductive_cmd_fn(p, meta).inductive_cmd();
}
void register_inductive_cmds(cmd_table & r) {
add_cmd(r, cmd_info("inductive", "declare an inductive datatype", inductive_cmd, false));
}
void initialize_inductive_cmds() {
register_trace_class("inductive");
register_trace_class(name({"inductive", "parse"}));
register_trace_class(name({"inductive", "elab"}));
register_trace_class(name({"inductive", "params"}));
register_trace_class(name({"inductive", "new_params"}));
register_trace_class(name({"inductive", "finalize"}));
register_trace_class(name({"inductive", "lp_names"}));
register_trace_class(name({"inductive", "infer_resultant"}));
register_trace_class(name({"inductive", "unify"}));
g_new_inductive = new name{"new_inductive"};
register_bool_option(*g_new_inductive, false, "use new inductive datatype module");
}
void finalize_inductive_cmds() {
delete g_new_inductive;
}
}