Lex Program To Check The Syntax of For Loop

Lex Code To check the syntax of For loop:-





Source code:-

1:  %{  

2:  #include<stdio.h>
3:  #include<ctype.h>
4:  int c;
5:  %}
6:  op "++"|"--"
7:  rop "<"|">"|"<="|">="|"=="|"!="
8:  id [a-zA-Z][a-zA-Z0-9]*
9:  no [0-9]*
10:  pp [\n\t" "]
11:  %%
12:  for\({id}=({no}|{id})\)?(,{id}=({no}|{id}))*\;({id}{rop}({id}|{no}))?\;({id}{op})?(,{id}{op})*\)\;?{pp}*\("{"(.*\n)*.*"}") {printf("correct");c=0;}
13:  .*    {printf("\nwrong");}
14:  %%
15:  main()
16:  { yyin=fopen("file11.c","r");
17:  yylex();
18:  }
19:  int yywrap()
20:  {return 1;
21:  }