examples: move the variant examples into the C++ directory

* examples/variant-11.test examples/variant-11.yy, * examples/variant.test examples/variant.yy: Move into examples/c++/. * examples/c++/README: New. * examples/README, examples/c++/local.mk, examples/local.mk: Adjust.
2026-03-20 17:53:02 +00:00 · 2018-10-23 21:04:06 +02:00
parent a4dce889a4
commit 8fd5f0d5a5
9 changed files with 71 additions and 35 deletions
--- a/examples/c++/README
+++ b/examples/c++/README
@@ -0,0 +1,38 @@
+This directory contains examples of Bison grammar files in C++.
+
+* Examples in C++
+
+** simple.yy - Simple example in C++14
+A very simple example in C++, based on variants and symbol constructors.
+Variants allow to use any C++ type as semantic value type, and symbol
+constructors ensure consistency between declared token type and effective
+semantic value.
+
+Extracted from the documentation: "A Simple C++ Example".
+https://www.gnu.org/software/bison/manual/html_node/A-Simple-C_002b_002b-Example.html
+
+** variant.yy - Self-contained example in C++98
+A varition of simple.yy, in C++98.
+
+** variant-11.yy - Self-contained example in modern C++
+Another variation of simple.yy, closely related to the previous one, but
+exhibiting support for C++11's move semantics.
+
+
+-----
+
+Local Variables:
+mode: outline
+fill-column: 76
+End:
+
+Copyright (C) 2018 Free Software Foundation, Inc.
+
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
+Texts.  A copy of the license is included in the "GNU Free
+Documentation License" file as part of this distribution.
+
+# LocalWords:  mfcalc calc parsers yy
--- a/examples/c++/local.mk
+++ b/examples/c++/local.mk
@@ -13,13 +13,16 @@
 ## You should have received a copy of the GNU General Public License
 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.

-## -------------------- ##
-## Building & testing.  ##
-## -------------------- ##
+cxxdir = $(examplesdir)/c++
+
+## -------- ##
+## Simple.  ##
+## -------- ##

 BUILT_SOURCES += $(simple_sources)
 CLEANFILES +=  %D%/simple.[ch] %D%/simple.output
 CLEANDIRS += %D%/*.dSYM
+cxx_DATA = $(simple_extracted)

 simple_extracted = %D%/simple.yy
 simple_sources = $(simple_extracted)
@@ -37,9 +40,24 @@ if ENABLE_CXX14
 endif


-## ------------ ##
-## Installing.  ##
-## ------------ ##
+## ---------- ##
+## Variants.  ##
+## ---------- ##

-cxxdir = $(docdir)/examples/c++
-cxx_DATA = $(simple_extracted)
+check_PROGRAMS += %D%/variant
+nodist_%C%_variant_SOURCES = %D%/variant.yy
+%C%_variant_CPPFLAGS = -I$(top_builddir)
+dist_TESTS += %D%/variant.test
+%D%/variant.cc: $(BISON_IN) $(dist_pkgdata_DATA)
+
+if ENABLE_CXX11
+  check_PROGRAMS += %D%/variant-11
+  nodist_%C%_variant_11_SOURCES = %D%/variant-11.yy
+  %C%_variant_11_CXXFLAGS = $(CXX11_CXXFLAGS)
+  %C%_variant_11_CPPFLAGS = -I$(top_builddir)
+  dist_TESTS += %D%/variant-11.test
+  %D%/variant-11.cc: $(BISON_IN) $(dist_pkgdata_DATA)
+endif
+
+dist_cxx_DATA = %D%/README %D%/variant.yy %D%/variant-11.yy
+CLEANFILES += %D%/variant.output %D%/variant-11.output
--- a/examples/c++/variant-11.test
+++ b/examples/c++/variant-11.test
@@ -0,0 +1,21 @@
+#! /bin/sh
+
+# Copyright (C) 2018 Free Software Foundation, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+: >input
+run 0 "{I have numbers for you., 1, 2, 3, And that's all!}" 4
+
+run 0 "{I have numbers for you., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399, 400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434, 435, 436, 437, 438, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 460, 461, 462, 463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499, 500, 501, 502, 503, 504, 505, 506, 507, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 520, 521, 522, 523, 524, 525, 526, 527, 528, 529, 530, 531, 532, 533, 534, 535, 536, 537, 538, 539, 540, 541, 542, 543, 544, 545, 546, 547, 548, 549, 550, 551, 552, 553, 554, 555, 556, 557, 558, 559, 560, 561, 562, 563, 564, 565, 566, 567, 568, 569, 570, 571, 572, 573, 574, 575, 576, 577, 578, 579, 580, 581, 582, 583, 584, 585, 586, 587, 588, 589, 590, 591, 592, 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609, 610, 611, 612, 613, 614, 615, 616, 617, 618, 619, 620, 621, 622, 623, 624, 625, 626, 627, 628, 629, 630, 631, 632, 633, 634, 635, 636, 637, 638, 639, 640, 641, 642, 643, 644, 645, 646, 647, 648, 649, 650, 651, 652, 653, 654, 655, 656, 657, 658, 659, 660, 661, 662, 663, 664, 665, 666, 667, 668, 669, 670, 671, 672, 673, 674, 675, 676, 677, 678, 679, 680, 681, 682, 683, 684, 685, 686, 687, 688, 689, 690, 691, 692, 693, 694, 695, 696, 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708, 709, 710, 711, 712, 713, 714, 715, 716, 717, 718, 719, 720, 721, 722, 723, 724, 725, 726, 727, 728, 729, 730, 731, 732, 733, 734, 735, 736, 737, 738, 739, 740, 741, 742, 743, 744, 745, 746, 747, 748, 749, 750, 751, 752, 753, 754, 755, 756, 757, 758, 759, 760, 761, 762, 763, 764, 765, 766, 767, 768, 769, 770, 771, 772, 773, 774, 775, 776, 777, 778, 779, 780, 781, 782, 783, 784, 785, 786, 787, 788, 789, 790, 791, 792, 793, 794, 795, 796, 797, 798, 799, 800, 801, 802, 803, 804, 805, 806, 807, 808, 809, 810, 811, 812, 813, 814, 815, 816, 817, 818, 819, 820, 821, 822, 823, 824, 825, 826, 827, 828, 829, 830, 831, 832, 833, 834, 835, 836, 837, 838, 839, 840, 841, 842, 843, 844, 845, 846, 847, 848, 849, 850, 851, 852, 853, 854, 855, 856, 857, 858, 859, 860, 861, 862, 863, 864, 865, 866, 867, 868, 869, 870, 871, 872, 873, 874, 875, 876, 877, 878, 879, 880, 881, 882, 883, 884, 885, 886, 887, 888, 889, 890, 891, 892, 893, 894, 895, 896, 897, 898, 899, 900, 901, 902, 903, 904, 905, 906, 907, 908, 909, 910, 911, 912, 913, 914, 915, 916, 917, 918, 919, 920, 921, 922, 923, 924, 925, 926, 927, 928, 929, 930, 931, 932, 933, 934, 935, 936, 937, 938, 939, 940, 941, 942, 943, 944, 945, 946, 947, 948, 949, 950, 951, 952, 953, 954, 955, 956, 957, 958, 959, 960, 961, 962, 963, 964, 965, 966, 967, 968, 969, 970, 971, 972, 973, 974, 975, 976, 977, 978, 979, 980, 981, 982, 983, 984, 985, 986, 987, 988, 989, 990, 991, 992, 993, 994, 995, 996, 997, 998, 999, And that's all!}" 1000
--- a/examples/c++/variant-11.yy
+++ b/examples/c++/variant-11.yy
@@ -0,0 +1,162 @@
+/*
+  Copyright (C) 2008-2015, 2018 Free Software Foundation, Inc.
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+%require "3.2"
+%debug
+%language "c++"
+%define api.token.constructor
+%define api.value.type variant
+%define api.value.automove
+%define api.location.file none
+%define parse.assert
+%locations
+
+%code requires // *.hh
+{
+#include <memory> // std::unique_ptr
+#include <string>
+#include <vector>
+
+  using string_uptr = std::unique_ptr<std::string>;
+  using string_uptrs = std::vector<string_uptr>;
+}
+
+%code // *.cc
+{
+#include <algorithm>
+#include <iostream>
+#include <iterator>
+#include <sstream>
+
+  namespace yy
+  {
+    // Prototype of the yylex function providing subsequent tokens.
+    static parser::symbol_type yylex ();
+
+    // Print a vector of strings.
+    std::ostream&
+    operator<< (std::ostream& o, const string_uptrs& ss)
+    {
+      o << '{';
+      const char *sep = "";
+      for (const auto& s: ss)
+        {
+          o << sep << *s;
+          sep = ", ";
+        }
+      return o << '}';
+    }
+  }
+
+  template <typename... Args>
+  string_uptr
+  make_string_uptr (Args&&... args)
+  {
+    // std::make_unique is C++14.
+    return string_uptr (new std::string{std::forward<Args> (args)...});
+  }
+
+  // Convert to string.
+  template <typename T>
+    std::string
+    to_string (const T& t)
+  {
+    auto&& o = std::ostringstream{};
+    o << t;
+    return o.str ();
+  }
+}
+
+%token <string_uptr> TEXT;
+%token <int> NUMBER;
+%printer { yyo << '(' << &$$ << ") " << $$; } <*>;
+%printer { yyo << *$$; } <string_uptr>;
+%token END_OF_FILE 0;
+
+%type <string_uptr> item;
+%type <string_uptrs> list;
+
+%%
+
+result:
+  list  { std::cout << $1 << '\n'; }
+;
+
+list:
+  %empty     { /* Generates an empty string list */ }
+| list item  { $$ = $1; $$.emplace_back ($2); }
+;
+
+item:
+  TEXT
+| NUMBER  { $$ = make_string_uptr (to_string ($1)); }
+;
+%%
+
+// The last number return by the scanner is max - 1.
+int max = 4;
+
+namespace yy
+{
+  // The yylex function providing subsequent tokens:
+  // TEXT         "I have three numbers for you."
+  // NUMBER       1
+  // NUMBER       2
+  // NUMBER       ...
+  // NUMBER       max - 1
+  // TEXT         "And that's all!"
+  // END_OF_FILE
+
+  static
+  parser::symbol_type
+  yylex ()
+  {
+    static int count = 0;
+    const int stage = count;
+    ++count;
+    auto loc = parser::location_type{nullptr, unsigned (stage + 1), unsigned (stage + 1)};
+    if (stage == 0)
+      return parser::make_TEXT (make_string_uptr ("I have numbers for you."), std::move (loc));
+    else if (stage < max)
+      return parser::make_NUMBER (stage, std::move (loc));
+    else if (stage == max)
+      return parser::make_TEXT (make_string_uptr ("And that's all!"), std::move (loc));
+    else
+      return parser::make_END_OF_FILE (std::move (loc));
+  }
+
+  // Mandatory error function
+  void
+  parser::error (const parser::location_type& loc, const std::string& msg)
+  {
+    std::cerr << loc << ": " << msg << '\n';
+  }
+}
+
+int
+main (int argc, const char *argv[])
+{
+  if (2 <= argc && isdigit (*argv[1]))
+    max = strtol (argv[1], nullptr, 10);
+  auto&& p = yy::parser{};
+  p.set_debug_level (!!getenv ("YYDEBUG"));
+  return p.parse ();
+}
+
+// Local Variables:
+// mode: C++
+// End:
--- a/examples/c++/variant.test
+++ b/examples/c++/variant.test
@@ -0,0 +1,19 @@
+#! /bin/sh
+
+# Copyright (C) 2018 Free Software Foundation, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+: >input
+run 0 "{I have three numbers for you., 1, 2, 3, And that's all!}"
--- a/examples/c++/variant.yy
+++ b/examples/c++/variant.yy
@@ -0,0 +1,156 @@
+/*
+  Copyright (C) 2008-2015, 2018 Free Software Foundation, Inc.
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+%require "3.2"
+%debug
+%language "c++"
+%define api.token.constructor
+%define api.value.type variant
+%define api.location.file none
+%define parse.assert
+%locations
+
+%code requires // *.hh
+{
+#include <string>
+#include <vector>
+typedef std::vector<std::string> strings_type;
+}
+
+%code // *.cc
+{
+#include <algorithm>
+#include <iostream>
+#include <iterator>
+#include <sstream>
+
+  namespace yy
+  {
+    // Prototype of the yylex function providing subsequent tokens.
+    static parser::symbol_type yylex ();
+
+    // Print a vector of strings.
+    std::ostream&
+    operator<< (std::ostream& o, const strings_type& ss)
+    {
+      o << '{';
+      const char *sep = "";
+      for (strings_type::const_iterator i = ss.begin (), end = ss.end ();
+           i != end; ++i)
+        {
+          o << sep << *i;
+          sep = ", ";
+        }
+      return o << '}';
+    }
+  }
+
+  // Convert to string.
+  template <typename T>
+    std::string
+    to_string (const T& t)
+  {
+    std::ostringstream o;
+    o << t;
+    return o.str ();
+  }
+}
+
+%token <::std::string> TEXT;
+%token <int> NUMBER;
+%printer { yyo << '(' << &$$ << ") " << $$; } <*>;
+%token END_OF_FILE 0;
+
+%type <::std::string> item;
+%type <::std::vector<std::string>> list;
+
+%%
+
+result:
+  list  { std::cout << $1 << '\n'; }
+;
+
+list:
+  %empty     { /* Generates an empty string list */ }
+| list item  { std::swap ($$, $1); $$.push_back ($2); }
+;
+
+item:
+  TEXT
+| NUMBER  { $$ = to_string ($1); }
+;
+%%
+
+namespace yy
+{
+  // Use nullptr with pre-C++11.
+#if defined __cplusplus && __cplusplus < 201103L
+# define NULLPTR 0
+#else
+# define NULLPTR nullptr
+#endif
+
+  // The yylex function providing subsequent tokens:
+  // TEXT         "I have three numbers for you."
+  // NUMBER       1
+  // NUMBER       2
+  // NUMBER       3
+  // TEXT         "And that's all!"
+  // END_OF_FILE
+
+  static
+  parser::symbol_type
+  yylex ()
+  {
+    static int count = 0;
+    const int stage = count;
+    ++count;
+    parser::location_type loc (NULLPTR, unsigned (stage + 1), unsigned (stage + 1));
+    switch (stage)
+      {
+      case 0:
+        return parser::make_TEXT ("I have three numbers for you.", loc);
+      case 1:
+      case 2:
+      case 3:
+        return parser::make_NUMBER (stage, loc);
+      case 4:
+        return parser::make_TEXT ("And that's all!", loc);
+      default:
+        return parser::make_END_OF_FILE (loc);
+      }
+  }
+
+  // Mandatory error function
+  void
+  parser::error (const parser::location_type& loc, const std::string& msg)
+  {
+    std::cerr << loc << ": " << msg << '\n';
+  }
+}
+
+int
+main ()
+{
+  yy::parser p;
+  p.set_debug_level (!!getenv ("YYDEBUG"));
+  return p.parse ();
+}
+
+// Local Variables:
+// mode: C++
+// End: