This can be done either before of after yacc, as lex does not depend directly on the token definitions: Lex builds C source for a lexical analyzer. It is usual to exercise the option to get the definitions, and to #include their header in the lexer's source file ( #include 'y.tab.h'):
Yacc builds C source for a parser and optionally a header file containing corresponding token definitions. Having solved that problem, your expectation of the program's behavior with the given input is incorrect in at least two ways. Having sorted out how to build your program, it does not work at all, instead segfaulting before reading any input. The build details you describe do not follow the usual pattern, and in fact they do not work for the code you provide.
* search down the list looking for the word */ Wp->word_name = (char *) malloc(strlen(word)+1) * have to copy the word itself as well */ Wp = (struct word *) malloc(sizeof(struct word)) * word not there, allocate a new entry and link it on the list */ Printf("!!! warning: word %s already defined \n", word) Struct word *word_list /* first element in word list */ * define a linked list of words and types */ #define LOOKUP 0 /* default - not a defined word type. #include "ch1-06y.h" /* token codes from the parser */ * We now build a lexical analyzer to be used by a higher-level parser. | compound_sentence CONJUNCTION simple_sentence Sentence: simple_sentence Ĭompound_sentence: simple_sentence CONJUNCTION simple_sentence %token NOUN PRONOUN VERB ADVERB ADJECTIVE PREPOSITION CONJUNCTION * we found the following required for some yacc implementations. It shows noting on screen where it is supposed to show the line "Parsed a simple sentence." on parsing.The code is given below The program asks the user for input of verbs,nouns,prepositions e.t.c in the format verb accept,admire,rejectĪnd then runs the grammar in yacc to check if it's a simple or compound sentence Levine i have compiled the lex and yacc program in linux using the commands lex example.l Hi i am trying to run John code from lex and yacc book by R.
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