syntax analysis with simplified shell grammar

+ TODO : bug to fix in lexer.c

Makefile

@@ -5,7 +5,7 @@ CC = clang
 CFLAGS = -Wall -Wextra -Werror $(INCLUDES) -g
 
 VPATH  = $(DIR_SRCS)
-DIR_SRCS = srcs srcs/builtins
+DIR_SRCS = srcs srcs/builtins srcs/parsing
 
 INCLUDES = -I$(HEADERS_D) -I$(LIBFT_D)
 
@@ -24,6 +24,8 @@ LIBFT = $(LIBFT_D)/libft.a
 SRCS =	main.c init.c free.c generic.c \
 		shell_loop.c \
 		lexing.c \
+		parsing.c \
+		valid_syntax.c valid_pipeline.c valid_command.c valid_io_redirect.c \
 		env.c exit.c echo.c 
 
 DIR_OBJS = builds