Please post your solutions to the Sep 22 In-Class Exercise to this thread.

Best,

Chris

<pre>From lextest.c: #line 2 "lextest.c"

#line 4 "lextest.c"

#define YY_INT_ALIGNED short int

/* A lexical scanner generated by flex */

Code: %{ #include <stdio.h> int wordCount = 0; %} word a|(the) %% [\t\n ]+ {printf("I see whitespace\n");} {word} {wordCount++;} %% int main() { yylex(); //call the lexer. Gets input from command line until ^D printf("word count: %d", wordCount); return 0; } </pre>

%{ #include <stdio.h> int articleCount = 0; %} article [^a\s\t\n]+ article [^the\s\t\n]+ %% [\t\n ]+ {printf("I see 'a' or 'the'\n");} //what to do if see pattern {article} {articleCount++;} %% int main() { yylex(); //calls the lexer printf("article count: %d", articleCount); return 0; }

<pre> code from lex.yy.c:

#line 2 "lex.yy.c"

#define YY_INT_ALIGNED short int

/* A lexical scanner generated by flex */

#define FLEX_SCANNER #define YY_FLEX_MAJOR_VERSION 2 #define YY_FLEX_MINOR_VERSION 6 #define YY_FLEX_SUBMINOR_VERSION 4 #if YY_FLEX_SUBMINOR_VERSION > 0 #define FLEX_BETA #endif

inclass.l code:

%{ #include <stdio.h> int wordCount = 0; %} word a|the %% [\t\n ]+ {printf("I see whitespace\n");} //what to do if see pattern {word} {wordCount++;} %% int main() { yylex(); //call the lexer. Gets input from command line until ^D printf("word count: %d", wordCount); return 0; } To compile: lex -o lextest.c lextest.l #default output is lex.yy.c gcc lextest.c -o lextest -ll #-ll not needed if use flex. </pre>

%{ #include <stdio.h> int wordCount = 0; %} word a|the %% [\t\n ]+ {printf("I see whitespace\n");} //what to do if see pattern {word} {wordCount++;} %% int main() { yylex(); //call the lexer. Gets input from command line until ^D printf("word count: %d", wordCount); return 0; }

%{ include <stdio.h> int wordCount = 0; %} word a|the %% [\t\n ]+ {printf("I see whitespace\n");} //what to do if see pattern {word} {wordCount++;} %% int main() { yylex(); //call the lexer. Gets input from command line until ^D printf("word count: %d", wordCount); return 0; }

lextest.l :

%{ #include <stdio.h> int wordCount = 0; %} word a|the %% [\t\n ]+ {printf("I see an 'a' or a 'the' \n");} {word} {wordCount++;} %% int main() { yylex(); //call the lexer. Gets input from command line until ^D printf("word count: %d", wordCount); return 0; }

lextest.c :

#line 2 "lextest.c"

#line 4 "lextest.c"

#define YY_INT_ALIGNED short int

/* A lexical scanner generated by flex */

#define FLEX_SCANNER #define YY_FLEX_MAJOR_VERSION 2 #define YY_FLEX_MINOR_VERSION 5 #define YY_FLEX_SUBMINOR_VERSION 35 #if YY_FLEX_SUBMINOR_VERSION > 0 #define FLEX_BETA #endif

%{ #include <stdio.h> int wordCount = 0; %} word (a|the) %% [\t\n ]+ {printf("I see whitespace\n");} {word} {wordCount++;} %% int main() { yylex(); //call the lexer. Gets input from command line until ^D printf("word count: %d", wordCount); return 0; }

#line 2 "lex.yy.c"

#line 4 "lex.yy.c"

#define YY_INT_ALIGNED short int

/* A lexical scanner generated by flex */

#define FLEX_SCANNER #define YY_FLEX_MAJOR_VERSION 2 #define YY_FLEX_MINOR_VERSION 5 #define YY_FLEX_SUBMINOR_VERSION 35 #if YY_FLEX_SUBMINOR_VERSION > 0 #define FLEX_BETA #endif

%{ #include <stdio.h> int wordCount = 0; %} word [^a\s\t\n]+|[^the\s\t\n]+ %% [\t\n ]+ {printf("I see whitespace\n");} //what to do if see pattern {word} {wordCount++;} %% int main() { yylex(); //call the lexer. Gets input from command line until ^D printf("word count: %d", wordCount); return 0; }

<nowiki>lextest.l:

{% #include <stdio.h> int aTheCount = 0; %} word a|(the); %% {word} {aTheCount++;} %% int main() { yylex(); //call the lexer. Gets input from command line until ^D printf("occurrences of 'a' and 'the': %d", aTheCount); return 0; }</nowiki>

<nowiki>result:

> lex lextest.l > gcc lex.yy.c -ll -o example > ./example > the girl saw a dog the girl sw dog occurrences of 'a' and 'the': 2</nowiki>