MAKEFILE:
=========

<makefile> ::= '(' + "makefile" + <makerule-clause>* + ')'

<makerule-clause> ::= <file-clause> 
		      | <all-clause>
		      | <md5-clause> 
		      | <always-clause> 
		      | <once-clause>

<file-clause> ::= '(' + <fille-clause-identifier>
		      + <target-spec> 
	              + <prereq-spec> 
		      + <action>+ + ')'

<all-clause> ::= '(' + <all-clause-identifier>
		      + <target-spec> 
	              + <prereq-spec> 
		      + <action>+ + ')'

<md5-clause> ::= '(' + <md5-clause-identifier>
                     + <target-spec> 
	             + <prereq-spec> 
		     + <action-spec> + ')'

<always-clause> ::= '(' + <always-clause-identifier>
		        + <target-spec> 
	                + <prereq-spec> 
		        + <action-spec> + ')'

<once-clause> ::= '(' + <once-clause-identifier>
		      + <target-spec> 
	              + <prereq-spec> 
		      + <action-spec> + ')'

<file-clause-identifier> ::= "file" 
                             | "makefile-rule" 
                             | "is-out-of-date?"

<all-clause-identifier> ::= "all" 
                             | "file-all" 
                             | "all-out-of-date?"

<md5-clause-identifier> ::= "md5" 
                            | "file-md5" 
                            | "fp-changed?"

<always-clause-identifier> ::= "always" 
                               | "file-always" 
                               | "phony" 
                               | "is-out-of-date!"

<once-clause-identifier> ::= "once" 
                             | "file-once"

<target-spec> ::= <target> | <target-list>
<target> ::= <filename>
<target-list> ::= '(' + <filename>+ + ')'

<prereq-spec> ::= <prereq> | <prereq-list>
<prereq> ::= <filename>
<prereq-list> ::= '(' + <filename>* + ')'

<action> ::= <function-call> | <value>

<filename> ::= '"' + {<dir-separator> + { 'a'-'z''A'-'Z''0'-'9' ... }+ }+ + '"'