lexer.l

%option nounput
%option noinput
%{
#include <stdio.h>
#include "parser.h"
%}
%%
[_A-Za-z][_A-Za-z0-9]+ return(ID);
"["|"]"                return yytext[0];
\n
.                      return -1;
%%

Makefile

TARGET   = project
SOURCES  = lexer.y parser.l
OBJECTS  = lexer.o parser.o
CFLAGS   = -Wall -Wpedantic -Werror

all: $(TARGET)

$(TARGET): $(OBJECTS)
	$(CC) $^ -o $(TARGET)

tests: $(TESTS_S) $(TESTS_F)

parser.c: parser.y
	bison -dy $^ -o $@

lexer.c: lexer.l parser.c
	flex -t $< > $@

clean:
	rm -f $(TARGET) $(OBJECTS) parser.c lexer.c parser.h

.PHONY: all clean tests

parser.y

%{
#include <stdio.h>
#include <string.h>
int yyerror();
int yylex(void);

extern char *yytext;
%}

%token ID

%%
s: id | arrid;

arrid: ID '[' ']' { printf("arrid: %s\n", yytext); }
id:    ID { printf("id: %s\n", yytext); }
%%

int main() { return yyparse(); }
int yywrap() { return 1; }
int yyerror() { return 0; }