lean4-htt/src/frontends/lean/brackets.cpp
2016-10-15 13:40:57 -07:00

176 lines
7.1 KiB
C++

/*
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include "kernel/abstract.h"
#include "library/constants.h"
#include "library/placeholder.h"
#include "frontends/lean/parser.h"
#include "frontends/lean/util.h"
#include "frontends/lean/tokens.h"
#include "frontends/lean/structure_instance.h"
namespace lean {
/* Parse rest of the subtype expression prefix '{' id ':' expr '\\' ... */
static expr parse_subtype(parser & p, pos_info const & pos, expr const & local) {
parser::local_scope scope(p);
p.add_local(local);
expr pred = p.parse_expr();
p.check_token_next(get_rcurly_tk(), "invalid subtype, '}' expected");
bool use_cache = false;
pred = p.save_pos(Fun(local, pred, use_cache), pos);
expr subtype = p.save_pos(mk_constant(get_subtype_name()), pos);
return p.mk_app(subtype, pred, pos);
}
/* Parse rest of the set_of expression prefix '{' id ':' expr '|' ... */
static expr parse_set_of(parser & p, pos_info const & pos, expr const & local) {
parser::local_scope scope(p);
p.add_local(local);
expr pred = p.parse_expr();
p.check_token_next(get_rcurly_tk(), "invalid set_of, '}' expected");
bool use_cache = false;
pred = p.save_pos(Fun(local, pred, use_cache), pos);
expr set_of = p.save_pos(mk_constant(get_set_of_name()), pos);
return p.mk_app(set_of, pred, pos);
}
/* Create empty collection for '{' '}' */
static expr mk_empty_collection(parser & p, pos_info const & pos) {
return p.save_pos(mk_constant(get_emptyc_name()), pos);
}
/* Create singletoncollection for '{' expr '}' */
static expr mk_singleton(parser & p, pos_info const & pos, expr const & e) {
return p.mk_app(p.save_pos(mk_constant(get_singleton_name()), pos), e, pos);
}
/* Parse rest of the insertable '{' expr ... */
static expr parse_fin_set(parser & p, pos_info const & pos, expr const & e) {
lean_assert(p.curr_is_token(get_comma_tk()) || p.curr_is_token(get_rcurly_tk()));
expr r = mk_singleton(p, pos, e);
while (p.curr_is_token(get_comma_tk())) {
auto ins_pos = p.pos();
p.next();
expr e2 = p.parse_expr();
expr insert = p.save_pos(mk_constant(get_insert_name()), ins_pos);
r = p.rec_save_pos(mk_app(insert, e2, r), ins_pos);
}
p.check_token_next(get_rcurly_tk(), "invalid explicit finite collection, '}' expected");
return r;
}
/* Parse rest of the sep expression '{' id '∈' ... */
static expr parse_sep(parser & p, pos_info const & pos, name const & id) {
expr s = p.parse_expr();
p.check_token_next(get_bar_tk(), "invalid sep expression, '|' expected");
parser::local_scope scope(p);
expr local = p.save_pos(mk_local(id, p.save_pos(mk_expr_placeholder(), pos)), pos);
p.add_local(local);
expr pred = p.parse_expr();
p.check_token_next(get_rcurly_tk(), "invalid sep expression, '}' expected");
bool use_cache = false;
pred = p.rec_save_pos(Fun(local, pred, use_cache), pos);
return p.rec_save_pos(mk_app(mk_constant(get_sep_name()), pred, s), pos);
}
static expr parse_structure_instance_core(parser & p, optional<expr> const & src, name const & S, name const & fname) {
buffer<name> fns;
buffer<expr> fvs;
fns.push_back(fname);
p.check_token_next(get_assign_tk(), "invalid structure instance, ':=' expected");
fvs.push_back(p.parse_expr());
while (p.curr_is_token(get_comma_tk())) {
p.next();
fns.push_back(p.check_id_next("invalid structure instance, identifier expected"));
p.check_token_next(get_assign_tk(), "invalid structure instance, ':=' expected");
fvs.push_back(p.parse_expr());
}
p.check_token_next(get_rcurly_tk(), "invalid structure instance, '}' expected");
if (src)
return mk_structure_instance(*src, fns, fvs);
else
return mk_structure_instance(S, fns, fvs);
}
/* Parse rest of the qualified structure instance prefix '{' S '.' ... */
static expr parse_qualified_structure_instance(parser & p, name const & S) {
name fname = p.check_id_next("invalid structure instance, identifier expected");
return parse_structure_instance_core(p, none_expr(), S, fname);
}
/* Parse rest of the structure instance prefix '{' fname ... */
static expr parse_structure_instance(parser & p, name const & fname) {
return parse_structure_instance_core(p, none_expr(), name(), fname);
}
/* Parse rest of the structure instance update '{' expr 'with' ... */
static expr parse_structure_instance_update(parser & p, expr const & e) {
name fname = p.check_id_next("invalid structure update, identifier expected");
return parse_structure_instance_core(p, some_expr(e), name(), fname);
}
expr parse_curly_bracket(parser & p, unsigned, expr const *, pos_info const & pos) {
expr e;
if (p.curr_is_token(get_rcurly_tk())) {
p.next();
return mk_empty_collection(p, pos);
} else if (p.curr_is_identifier()) {
auto id_pos = p.pos();
name id = p.get_name_val();
p.next();
if (p.curr_is_token(get_dslash_tk())) {
expr type = p.save_pos(mk_expr_placeholder(), id_pos);
expr local = p.save_pos(mk_local(id, type), id_pos);
p.next();
return parse_subtype(p, pos, local);
} else if (p.curr_is_token(get_bar_tk())) {
expr type = p.save_pos(mk_expr_placeholder(), id_pos);
expr local = p.save_pos(mk_local(id, type), id_pos);
p.next();
return parse_set_of(p, pos, local);
} else if (p.curr_is_token(get_colon_tk())) {
p.next();
expr type = p.parse_expr();
expr local = p.save_pos(mk_local(id, type), id_pos);
if (p.curr_is_token(get_bar_tk())) {
p.next();
return parse_set_of(p, pos, local);
} else {
p.check_token_next(get_dslash_tk(), "invalid expression, '//' or '|' expected");
return parse_subtype(p, pos, local);
}
} else if (p.curr_is_token(get_period_tk())) {
p.next();
return parse_qualified_structure_instance(p, id);
} else if (p.curr_is_token(get_assign_tk()) || p.curr_is_token(get_fieldarrow_tk())) {
return parse_structure_instance(p, id);
} else if (p.curr_is_token(get_membership_tk()) || p.curr_is_token(get_in_tk())) {
p.next();
return parse_sep(p, pos, id);
} else {
expr left = p.id_to_expr(id, id_pos);
unsigned rbp = 0;
while (rbp < p.curr_lbp()) {
left = p.parse_led(left);
}
e = left;
}
} else {
e = p.parse_expr();
}
if (p.curr_is_token(get_comma_tk())) {
return parse_fin_set(p, pos, e);
} else if (p.curr_is_token(get_rcurly_tk())) {
return parse_fin_set(p, pos, e);
} else if (p.curr_is_token(get_with_tk())) {
p.next();
return parse_structure_instance_update(p, e);
} else {
throw parser_error("invalid '{' expression, ',', '}', 'with', `//` or `|` expected", p.pos());
}
}
}