97 lines
3.4 KiB
C++
97 lines
3.4 KiB
C++
/*
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Copyright (c) 2014 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Leonardo de Moura
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*/
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#include <limits>
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#include <string>
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#include "frontends/lean/parser.h"
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namespace lean {
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static name g_max("max");
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static name g_colon(":");
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static name g_assign(":=");
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static std::string parse_symbol(parser & p, char const * msg) {
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name n;
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if (p.curr_is_identifier() || p.curr_is_quoted_symbol()) {
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n = p.get_name_val();
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} else if (p.curr_is_keyword()) {
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n = p.get_token_info().value();
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} else {
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throw parser_error(msg, p.pos());
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}
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p.next();
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return n.to_string();
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}
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static optional<unsigned> parse_optional_precedence(parser & p) {
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if (p.curr_is_numeral()) {
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return optional<unsigned>(p.parse_small_nat());
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} else if (p.curr_is_token_or_id(g_max)) {
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p.next();
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return optional<unsigned>(std::numeric_limits<unsigned>::max());
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} else {
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return optional<unsigned>();
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}
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}
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static unsigned parse_precedence(parser & p, char const * msg) {
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auto r = parse_optional_precedence(p);
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if (!r)
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throw parser_error(msg, p.pos());
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return *r;
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}
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environment precedence_cmd(parser & p) {
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std::string tk = parse_symbol(p, "invalid precedence declaration, quoted symbol or identifier expected");
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p.check_token_next(g_colon, "invalid precedence declaration, ':' expected");
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unsigned prec = parse_precedence(p, "invalid precedence declaration, numeral or 'max' expected");
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return add_token(p.env(), tk.c_str(), prec);
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}
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enum class mixfix_kind { infixl, infixr, postfix };
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using notation::mk_expr_action;
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using notation::mk_skip_action;
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using notation::transition;
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environment mixfix_cmd(parser & p, mixfix_kind k) {
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std::string tk = parse_symbol(p, "invalid notation declaration, quoted symbol or identifier expected");
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optional<unsigned> prec = parse_optional_precedence(p);
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environment env = p.env();
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if (!prec) {
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prec = get_precedence(get_token_table(env), tk.c_str());
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} else if (prec != get_precedence(get_token_table(env), tk.c_str())) {
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env = add_token(env, tk.c_str(), *prec);
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}
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if (!prec)
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throw parser_error("invalid notation declaration, precedence was not provided, and it is not set for the given symbol, "
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"solution: use the 'precedence' command", p.pos());
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if (k == mixfix_kind::infixr && *prec == 0)
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throw parser_error("invalid infixr declaration, precedence must be greater than zero", p.pos());
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p.check_token_next(g_assign, "invalid notation declaration, ':=' expected");
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expr f = p.parse_expr();
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char const * tks = tk.c_str();
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switch (k) {
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case mixfix_kind::infixl:
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return add_led_notation(env, {transition(tks, mk_expr_action(*prec))}, mk_app(f, Var(0), Var(1)));
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case mixfix_kind::infixr:
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return add_led_notation(env, {transition(tks, mk_expr_action(*prec-1))}, mk_app(f, Var(0), Var(1)));
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case mixfix_kind::postfix:
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return add_led_notation(env, {transition(tks, mk_skip_action())}, mk_app(f, Var(0)));
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}
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lean_unreachable(); // LCOV_EXCL_LINE
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}
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environment infixl_cmd(parser & p) { return mixfix_cmd(p, mixfix_kind::infixl); }
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environment infixr_cmd(parser & p) { return mixfix_cmd(p, mixfix_kind::infixr); }
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environment postfix_cmd(parser & p) { return mixfix_cmd(p, mixfix_kind::postfix); }
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environment notation_cmd(parser & p) {
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// TODO(Leo)
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return p.env();
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}
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}
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