doc/bison.info-5

   1 This is bison.info, produced by makeinfo version 4.0 from bison.texinfo.
   2
   3 START-INFO-DIR-ENTRY
   4 * bison: (bison).       GNU Project parser generator (yacc replacement).
   5 END-INFO-DIR-ENTRY
   6
   7    This file documents the Bison parser generator.
   8
   9    Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1995, 1998, 1999,
  10 2000 Free Software Foundation, Inc.
  11
  12    Permission is granted to make and distribute verbatim copies of this
  13 manual provided the copyright notice and this permission notice are
  14 preserved on all copies.
  15
  16    Permission is granted to copy and distribute modified versions of
  17 this manual under the conditions for verbatim copying, provided also
  18 that the sections entitled "GNU General Public License" and "Conditions
  19 for Using Bison" are included exactly as in the original, and provided
  20 that the entire resulting derived work is distributed under the terms
  21 of a permission notice identical to this one.
  22
  23    Permission is granted to copy and distribute translations of this
  24 manual into another language, under the above conditions for modified
  25 versions, except that the sections entitled "GNU General Public
  26 License", "Conditions for Using Bison" and this permission notice may be
  27 included in translations approved by the Free Software Foundation
  28 instead of in the original English.
  29
  30 \1f
  31 File: bison.info,  Node: Glossary,  Next: Index,  Prev: Table of Symbols,  Up: Top
  32
  33 Glossary
  34 ********
  35
  36 Backus-Naur Form (BNF)
  37      Formal method of specifying context-free grammars.  BNF was first
  38      used in the `ALGOL-60' report, 1963.  *Note Languages and
  39      Context-Free Grammars: Language and Grammar.
  40
  41 Context-free grammars
  42      Grammars specified as rules that can be applied regardless of
  43      context.  Thus, if there is a rule which says that an integer can
  44      be used as an expression, integers are allowed _anywhere_ an
  45      expression is permitted.  *Note Languages and Context-Free
  46      Grammars: Language and Grammar.
  47
  48 Dynamic allocation
  49      Allocation of memory that occurs during execution, rather than at
  50      compile time or on entry to a function.
  51
  52 Empty string
  53      Analogous to the empty set in set theory, the empty string is a
  54      character string of length zero.
  55
  56 Finite-state stack machine
  57      A "machine" that has discrete states in which it is said to exist
  58      at each instant in time.  As input to the machine is processed, the
  59      machine moves from state to state as specified by the logic of the
  60      machine.  In the case of the parser, the input is the language
  61      being parsed, and the states correspond to various stages in the
  62      grammar rules.  *Note The Bison Parser Algorithm: Algorithm.
  63
  64 Grouping
  65      A language construct that is (in general) grammatically divisible;
  66      for example, `expression' or `declaration' in C.  *Note Languages
  67      and Context-Free Grammars: Language and Grammar.
  68
  69 Infix operator
  70      An arithmetic operator that is placed between the operands on
  71      which it performs some operation.
  72
  73 Input stream
  74      A continuous flow of data between devices or programs.
  75
  76 Language construct
  77      One of the typical usage schemas of the language.  For example,
  78      one of the constructs of the C language is the `if' statement.
  79      *Note Languages and Context-Free Grammars: Language and Grammar.
  80
  81 Left associativity
  82      Operators having left associativity are analyzed from left to
  83      right: `a+b+c' first computes `a+b' and then combines with `c'.
  84      *Note Operator Precedence: Precedence.
  85
  86 Left recursion
  87      A rule whose result symbol is also its first component symbol; for
  88      example, `expseq1 : expseq1 ',' exp;'.  *Note Recursive Rules:
  89      Recursion.
  90
  91 Left-to-right parsing
  92      Parsing a sentence of a language by analyzing it token by token
  93      from left to right.  *Note The Bison Parser Algorithm: Algorithm.
  94
  95 Lexical analyzer (scanner)
  96      A function that reads an input stream and returns tokens one by
  97      one.  *Note The Lexical Analyzer Function `yylex': Lexical.
  98
  99 Lexical tie-in
 100      A flag, set by actions in the grammar rules, which alters the way
 101      tokens are parsed.  *Note Lexical Tie-ins::.
 102
 103 Literal string token
 104      A token which consists of two or more fixed characters.  *Note
 105      Symbols::.
 106
 107 Look-ahead token
 108      A token already read but not yet shifted.  *Note Look-Ahead
 109      Tokens: Look-Ahead.
 110
 111 LALR(1)
 112      The class of context-free grammars that Bison (like most other
 113      parser generators) can handle; a subset of LR(1).  *Note
 114      Mysterious Reduce/Reduce Conflicts: Mystery Conflicts.
 115
 116 LR(1)
 117      The class of context-free grammars in which at most one token of
 118      look-ahead is needed to disambiguate the parsing of any piece of
 119      input.
 120
 121 Nonterminal symbol
 122      A grammar symbol standing for a grammatical construct that can be
 123      expressed through rules in terms of smaller constructs; in other
 124      words, a construct that is not a token.  *Note Symbols::.
 125
 126 Parse error
 127      An error encountered during parsing of an input stream due to
 128      invalid syntax.  *Note Error Recovery::.
 129
 130 Parser
 131      A function that recognizes valid sentences of a language by
 132      analyzing the syntax structure of a set of tokens passed to it
 133      from a lexical analyzer.
 134
 135 Postfix operator
 136      An arithmetic operator that is placed after the operands upon
 137      which it performs some operation.
 138
 139 Reduction
 140      Replacing a string of nonterminals and/or terminals with a single
 141      nonterminal, according to a grammar rule.  *Note The Bison Parser
 142      Algorithm: Algorithm.
 143
 144 Reentrant
 145      A reentrant subprogram is a subprogram which can be in invoked any
 146      number of times in parallel, without interference between the
 147      various invocations.  *Note A Pure (Reentrant) Parser: Pure Decl.
 148
 149 Reverse polish notation
 150      A language in which all operators are postfix operators.
 151
 152 Right recursion
 153      A rule whose result symbol is also its last component symbol; for
 154      example, `expseq1: exp ',' expseq1;'.  *Note Recursive Rules:
 155      Recursion.
 156
 157 Semantics
 158      In computer languages, the semantics are specified by the actions
 159      taken for each instance of the language, i.e., the meaning of each
 160      statement.  *Note Defining Language Semantics: Semantics.
 161
 162 Shift
 163      A parser is said to shift when it makes the choice of analyzing
 164      further input from the stream rather than reducing immediately some
 165      already-recognized rule.  *Note The Bison Parser Algorithm:
 166      Algorithm.
 167
 168 Single-character literal
 169      A single character that is recognized and interpreted as is.
 170      *Note From Formal Rules to Bison Input: Grammar in Bison.
 171
 172 Start symbol
 173      The nonterminal symbol that stands for a complete valid utterance
 174      in the language being parsed.  The start symbol is usually listed
 175      as the first nonterminal symbol in a language specification.
 176      *Note The Start-Symbol: Start Decl.
 177
 178 Symbol table
 179      A data structure where symbol names and associated data are stored
 180      during parsing to allow for recognition and use of existing
 181      information in repeated uses of a symbol.  *Note Multi-function
 182      Calc::.
 183
 184 Token
 185      A basic, grammatically indivisible unit of a language.  The symbol
 186      that describes a token in the grammar is a terminal symbol.  The
 187      input of the Bison parser is a stream of tokens which comes from
 188      the lexical analyzer.  *Note Symbols::.
 189
 190 Terminal symbol
 191      A grammar symbol that has no rules in the grammar and therefore is
 192      grammatically indivisible.  The piece of text it represents is a
 193      token.  *Note Languages and Context-Free Grammars: Language and
 194      Grammar.
 195
 196 \1f
 197 File: bison.info,  Node: Index,  Prev: Glossary,  Up: Top
 198
 199 Index
 200 *****
 201
 202 * Menu:
 203
 204 * $$:                                    Actions.
 205 * $N:                                    Actions.
 206 * %expect:                               Expect Decl.
 207 * %left:                                 Using Precedence.
 208 * %nonassoc:                             Using Precedence.
 209 * %prec:                                 Contextual Precedence.
 210 * %pure_parser:                          Pure Decl.
 211 * %right:                                Using Precedence.
 212 * %start:                                Start Decl.
 213 * %token:                                Token Decl.
 214 * %type:                                 Type Decl.
 215 * %union:                                Union Decl.
 216 * @N:                                    Action Features.
 217 * action:                                Actions.
 218 * action data types:                     Action Types.
 219 * action features summary:               Action Features.
 220 * actions in mid-rule:                   Mid-Rule Actions.
 221 * actions, semantic:                     Semantic Actions.
 222 * additional C code section:             C Code.
 223 * algorithm of parser:                   Algorithm.
 224 * associativity:                         Why Precedence.
 225 * Backus-Naur form:                      Language and Grammar.
 226 * Bison declaration summary:             Decl Summary.
 227 * Bison declarations:                    Declarations.
 228 * Bison declarations (introduction):     Bison Declarations.
 229 * Bison grammar:                         Grammar in Bison.
 230 * Bison invocation:                      Invocation.
 231 * Bison parser:                          Bison Parser.
 232 * Bison parser algorithm:                Algorithm.
 233 * Bison symbols, table of:               Table of Symbols.
 234 * Bison utility:                         Bison Parser.
 235 * BISON_HAIRY:                           Environment Variables.
 236 * BISON_SIMPLE:                          Environment Variables.
 237 * BNF:                                   Language and Grammar.
 238 * C code, section for additional:        C Code.
 239 * C declarations section:                C Declarations.
 240 * C-language interface:                  Interface.
 241 * calc:                                  Infix Calc.
 242 * calculator, infix notation:            Infix Calc.
 243 * calculator, multi-function:            Multi-function Calc.
 244 * calculator, simple:                    RPN Calc.
 245 * character token:                       Symbols.
 246 * compiling the parser:                  Rpcalc Compile.
 247 * conflicts:                             Shift/Reduce.
 248 * conflicts, reduce/reduce:              Reduce/Reduce.
 249 * conflicts, suppressing warnings of:    Expect Decl.
 250 * context-dependent precedence:          Contextual Precedence.
 251 * context-free grammar:                  Language and Grammar.
 252 * controlling function:                  Rpcalc Main.
 253 * dangling else:                         Shift/Reduce.
 254 * data types in actions:                 Action Types.
 255 * data types of semantic values:         Value Type.
 256 * debugging:                             Debugging.
 257 * declaration summary:                   Decl Summary.
 258 * declarations, Bison:                   Declarations.
 259 * declarations, Bison (introduction):    Bison Declarations.
 260 * declarations, C:                       C Declarations.
 261 * declaring literal string tokens:       Token Decl.
 262 * declaring operator precedence:         Precedence Decl.
 263 * declaring the start symbol:            Start Decl.
 264 * declaring token type names:            Token Decl.
 265 * declaring value types:                 Union Decl.
 266 * declaring value types, nonterminals:   Type Decl.
 267 * default action:                        Actions.
 268 * default data type:                     Value Type.
 269 * default stack limit:                   Stack Overflow.
 270 * default start symbol:                  Start Decl.
 271 * defining language semantics:           Semantics.
 272 * else, dangling:                        Shift/Reduce.
 273 * environment variables:                 Environment Variables.
 274 * error:                                 Error Recovery.
 275 * error recovery:                        Error Recovery.
 276 * error recovery, simple:                Simple Error Recovery.
 277 * error reporting function:              Error Reporting.
 278 * error reporting routine:               Rpcalc Error.
 279 * examples, simple:                      Examples.
 280 * exercises:                             Exercises.
 281 * file format:                           Grammar Layout.
 282 * finite-state machine:                  Parser States.
 283 * formal grammar:                        Grammar in Bison.
 284 * format of grammar file:                Grammar Layout.
 285 * glossary:                              Glossary.
 286 * grammar file:                          Grammar Layout.
 287 * grammar rule syntax:                   Rules.
 288 * grammar rules section:                 Grammar Rules.
 289 * grammar, Bison:                        Grammar in Bison.
 290 * grammar, context-free:                 Language and Grammar.
 291 * grouping, syntactic:                   Language and Grammar.
 292 * infix notation calculator:             Infix Calc.
 293 * interface:                             Interface.
 294 * introduction:                          Introduction.
 295 * invoking Bison:                        Invocation.
 296 * invoking Bison under VMS:              VMS Invocation.
 297 * LALR(1):                               Mystery Conflicts.
 298 * language semantics, defining:          Semantics.
 299 * layout of Bison grammar:               Grammar Layout.
 300 * left recursion:                        Recursion.
 301 * lexical analyzer:                      Lexical.
 302 * lexical analyzer, purpose:             Bison Parser.
 303 * lexical analyzer, writing:             Rpcalc Lexer.
 304 * lexical tie-in:                        Lexical Tie-ins.
 305 * literal string token:                  Symbols.
 306 * literal token:                         Symbols.
 307 * look-ahead token:                      Look-Ahead.
 308 * LR(1):                                 Mystery Conflicts.
 309 * main function in simple example:       Rpcalc Main.
 310 * mfcalc:                                Multi-function Calc.
 311 * mid-rule actions:                      Mid-Rule Actions.
 312 * multi-function calculator:             Multi-function Calc.
 313 * multicharacter literal:                Symbols.
 314 * mutual recursion:                      Recursion.
 315 * nonterminal symbol:                    Symbols.
 316 * operator precedence:                   Precedence.
 317 * operator precedence, declaring:        Precedence Decl.
 318 * options for invoking Bison:            Invocation.
 319 * overflow of parser stack:              Stack Overflow.
 320 * parse error:                           Error Reporting.
 321 * parser:                                Bison Parser.
 322 * parser stack:                          Algorithm.
 323 * parser stack overflow:                 Stack Overflow.
 324 * parser state:                          Parser States.
 325 * polish notation calculator:            RPN Calc.
 326 * precedence declarations:               Precedence Decl.
 327 * precedence of operators:               Precedence.
 328 * precedence, context-dependent:         Contextual Precedence.
 329 * precedence, unary operator:            Contextual Precedence.
 330 * preventing warnings about conflicts:   Expect Decl.
 331 * pure parser:                           Pure Decl.
 332 * recovery from errors:                  Error Recovery.
 333 * recursive rule:                        Recursion.
 334 * reduce/reduce conflict:                Reduce/Reduce.
 335 * reduction:                             Algorithm.
 336 * reentrant parser:                      Pure Decl.
 337 * reverse polish notation:               RPN Calc.
 338 * right recursion:                       Recursion.
 339 * rpcalc:                                RPN Calc.
 340 * rule syntax:                           Rules.
 341 * rules section for grammar:             Grammar Rules.
 342 * running Bison (introduction):          Rpcalc Gen.
 343 * semantic actions:                      Semantic Actions.
 344 * semantic value:                        Semantic Values.
 345 * semantic value type:                   Value Type.
 346 * shift/reduce conflicts:                Shift/Reduce.
 347 * shifting:                              Algorithm.
 348 * simple examples:                       Examples.
 349 * single-character literal:              Symbols.
 350 * stack overflow:                        Stack Overflow.
 351 * stack, parser:                         Algorithm.
 352 * stages in using Bison:                 Stages.
 353 * start symbol:                          Language and Grammar.
 354 * start symbol, declaring:               Start Decl.
 355 * state (of parser):                     Parser States.
 356 * string token:                          Symbols.
 357 * summary, action features:              Action Features.
 358 * summary, Bison declaration:            Decl Summary.
 359 * suppressing conflict warnings:         Expect Decl.
 360 * symbol:                                Symbols.
 361 * symbol table example:                  Mfcalc Symtab.
 362 * symbols (abstract):                    Language and Grammar.
 363 * symbols in Bison, table of:            Table of Symbols.
 364 * syntactic grouping:                    Language and Grammar.
 365 * syntax error:                          Error Reporting.
 366 * syntax of grammar rules:               Rules.
 367 * terminal symbol:                       Symbols.
 368 * token:                                 Language and Grammar.
 369 * token type:                            Symbols.
 370 * token type names, declaring:           Token Decl.
 371 * tracing the parser:                    Debugging.
 372 * unary operator precedence:             Contextual Precedence.
 373 * using Bison:                           Stages.
 374 * value type, semantic:                  Value Type.
 375 * value types, declaring:                Union Decl.
 376 * value types, nonterminals, declaring:  Type Decl.
 377 * value, semantic:                       Semantic Values.
 378 * VMS:                                   VMS Invocation.
 379 * warnings, preventing:                  Expect Decl.
 380 * writing a lexical analyzer:            Rpcalc Lexer.
 381 * YYABORT:                               Parser Function.
 382 * YYACCEPT:                              Parser Function.
 383 * YYBACKUP:                              Action Features.
 384 * yychar:                                Look-Ahead.
 385 * yyclearin:                             Error Recovery.
 386 * yydebug:                               Debugging.
 387 * YYDEBUG:                               Debugging.
 388 * YYEMPTY:                               Action Features.
 389 * yyerrok:                               Error Recovery.
 390 * YYERROR:                               Action Features.
 391 * yyerror:                               Error Reporting.
 392 * YYERROR_VERBOSE:                       Error Reporting.
 393 * YYINITDEPTH:                           Stack Overflow.
 394 * yylex:                                 Lexical.
 395 * YYLEX_PARAM:                           Pure Calling.
 396 * yylloc:                                Token Positions.
 397 * YYLTYPE:                               Token Positions.
 398 * yylval:                                Token Values.
 399 * YYMAXDEPTH:                            Stack Overflow.
 400 * yynerrs:                               Error Reporting.
 401 * yyparse:                               Parser Function.
 402 * YYPARSE_PARAM:                         Pure Calling.
 403 * YYPRINT:                               Debugging.
 404 * YYRECOVERING:                          Error Recovery.
 405 * |:                                     Rules.
 406
 407