EXPR =
- '<expr>' [ DEFUN | DEFVAR | TERM ] * '</expr>'
+ '<expr>' [ DEFUN | DEFMACRO | DEFVAR | TERM ] * '</expr>'
-TERM = [ INT | STRING | SYMBOL | LIST | VAR | FUNCALL ]
+TERM = [ INT | STRING | SYMBOL | LIST | ERROR | VARREF | FUNCALL ]
DEFUN =
- '<defun fname="' FNAME ? ">'
+ '<defun fname="' FNAME '">'
ARGS ?
TERM *
'</defun>'
+DEFMACRO =
+ '<defmacro fname="' FNAME '">'
+ ARGS ?
+ TERM *
+ '</defmacro>'
+
ARGS =
- '<args>' FIXED ? OPTIONAL ? REST ? '</args>'
- | '<args-unevalled>' FIXED ? OPTIONAL ? REST ? '</args-unevalled>'
+ '<args>' FIXED * OPTIONAL * REST ? '</args>'
FIXED =
- '<fixed> VAR + '</fixed>'
+ '<fixed vname="' VNAME '">'
OPTIONAL =
- '<optional>' VAR + '<optional>'
+ '<optional vname="' VNAME '">'
REST =
- '<rest>' VAR '</rest>'
+ '<rest vname="' VNAME '">'
-DEFVAR = DEFVAR-INT DEFVAR-STR DEFVAR-SYM
+DEFVAR = DEFVAR-INT | DEFVAR-STR | DEFVAR-SYM
DEFVAR-INT =
'<defvar vname="' VNAME '">'
SYMBOL =
'<symbol>' NAME '</symbol>'
LIST =
- '<list>' TERM * '</list>' | <list/>
+ '<list>' TERM * '</list>'
+ERROR =
+ [ '<error>' | '<error ename="' ENAME '">"' ] STRING '</error>'
-VAR =
+VARREF =
'<varref vname="' VNAME '"/>'
FUNCALL =
PREDEFINED =
SET
- | AND | OR | NOT
- | LT | LE | EQ | GE | GT | NOTEQ
+ | AND | OR | NOT | EQ | NOTEQ | EQUAL | MATCH
+ | LT | LE | GE | GT
| ADD | SUB | MUL | DIV | MOD
| LOGAND | LOGIOR | LOGXOR | LSH
| APPEND | CONCAT | LENGTH | NTH | COPY | INS | DEL
| PROGN | IF | WHEN | COND
- | LOOP | WHILE | FOREACH | BREAK | RETURN
+ | LOOP | WHILE | FOREACH | BREAK | RETURN | CATCH | THROW
| QUOTE | EVAL | TYPE
-;; TERM has a value, and is evaluated to a TERM as below.
-;; INT has an integer value, and is evaluated to itself .
-;; STRING has a string value, and is evaluated to itself.
-;; SYMBOL has a symbol value, and is evaluated to itself.
-;; LIST has a list value and, is evaluated to itself.
-;; VAR has a value of TERM that is assigned to the variable,
-;; and is evalued to that TERM.
-;; FUNCALL has a value of TERM that is returned by that function,
-;; and is evalued to that TERM.
+;; TERM contains an object, and is evaluated to a TERM as below.
+;; INT contains an integer, and is evaluated to itself .
+;; Two integers of the same value are regarded as the same object.
+;; STRING contains a string, and is evaluated to itself.
+;; SYMBOL contains a named symbol, and is evaluated to itself.
+;; Two symbols of the same name are reguarded as the same object.
+;; LIST contains a list and, is evaluated to itself.
+;; ERROR contains an error type symbol and an error message (optional).
+;; VARREF contains a variable, and is evalued to the value of that variable.
+;; FUNCALL contains a function and arguments to it, and is evalued to the
+;; value of function called with those arguments.
INTTERM = INT | VAR (value is INT) | FUNCALL (return INT)
STRTERM = STR | VAR (value is STR) | FUNCALL (return STR)
SYMTERM = SYMBOL | VAR (value is SYMBOL) | FUNCALL (return SYMBOL)
LISTTERM = LIST | VAR (value is LIST) | FUNCALL (return LIST)
+XXXTERM = TERM
+
+;; Here after, when an argument written as TERM, it is given to a
+;; function without being evaluted. Otherwise, an evaluated term is
+;; given. "the value is NUM" means "the value is
+;; <integer>NUM</integer>".
+
+SET = '<set vname="' VNAME '">' XXXTERM '</set>'
-;; Here after, when an argument is TERM, it is given to a function
-;; without being evaluted. Otherwise, an evaluated term is given.
+;; Set the value of the variable VNAME to XXXTERM, and the value is
+;; XXXTERM.
-SET = '<set vname="' VNAME '">' TERM '</set>'
ADD = '<add>' INTTERM + '</add>'
| '<add vname="' VNAME '">' INTTERM + '</add>'
SUB = '<sub>' INTTERM + '</sub>'
| '<lsh vname="' VNAME '">' INTTERM '</mul>'
LT = '<lt>' INTTERM INTTERM '</lt>'
LE = '<le>' INTTERM INTTERM '</le>'
-EQ = '<eq>' INTTERM INTTERM '</eq>'
-NOTEQ = '<noteq>' INTTERM INTTERM '</noteq>'
GE = '<ge>' INTTERM INTTERM '</ge>'
GT ='<gt>' INTTERM INTTERM '</gt>'
-APPEND = '<append>' TERM + '</append>'
- | '<append vname=" VNAME '">' TERM + '</append>'
-CONCAT = '<concat>' [ INTTERM | STRTERM | LISTTERM ] + '</concat>'
- | '<concat vname=" VNAME '">' [ INTTERM | STRTERM | LISTTERM ] + '</concat>'
+
+EQ = '<eq>' XXXTERM + '</eq>'
+
+;; If XXXTERMs have the same object, the value is 1. Otherwise the
+;; value is 0.
+
+NOTEQ = '<noteq>' XXXTERM XXXTERM '</noteq>'
+
+;; If XXXTERMs have the same object, the value is 0. Othersise the
+;; value is 1.
+
+APPEND = '<append>' XXXTERM + '</append>'
+ | '<append vname=" VNAME '">' XXXTERM + '</append>'
+
+;; In the first form, the value is a LIST made by concatinating all
+;; elements of XXXTERM (if it is a LIST) or XXXTERM itself (if it is
+;; not a LIST) in the specified order.
+
+;; In the second form, the value of the variable VNAME must be a LIST,
+;; and that LIST is modified destructively by concatinating ANYterms
+;; in the same manner as the previous case. The value is the
+;; resulting LIST.
+
+CONCAT = '<concat>' [ STRTERM | INTTERM | LISTTERM ] + '</concat>'
+ | '<concat vname=" VNAME '">' [ STRTERM | INTTERM | LISTTERM ] + '</concat>'
+
+;; In the first form, the value is a STR made by concatinating all
+;; the strings made from the arguments as below:
+;; STRTERM gives a string contained in it.
+;; INTTERM gives a string of a character whose code is INTTERM's integer.
+;; LISTTERM must contain only INTTERMs, and give a string containing
+;; characters whose codes are INTTERM's integer.
+
+;; In the second form, the value of the variable VNAME must be a STR,
+;; and that STR is modified destructively by concatinating the
+;; arguments in the same manner as the previous case. The value is
+;; the resulting STR.
+
LENGTH = '<length>' [ STRTERM | LISTTERM ] '</length>'
NTH = '<nth>' INTTERM [ STRTERM | LISTTERM ] '</nth>'
-COPY = '<copy>' LISTTERM '</nth>'
+COPY = '<copy>' [ STRTERM | LISTTERM ] '</nth>'
INS = '<ins vname="' VNAME '">' INTTERM [ STRTERM | LISTTERM ] '</ins>'
DEL = '<del vname="' VNAME '">' INTTERM INTTERM '</ins>'
+
AND = '<and>' TERM + '</and>'
+
+;; Evaluates TERMs one by one until one is evaluated to 0. If none is
+;; evaluated to 0, the value is 1. Othersise the value is 0.
+
OR = '<or>' TERM + '</or>'
-NOT = '<not>' TERM '</not>'
+
+;; Evaluates TERMs one by one until one is evaluated not to 0. If
+;; none is evaluated not to 0, the value is 0. Othersise the value is
+;; 1.
+
+NOT = '<not>' XXXTERM '</not>'
+
+;; If XXX is 0, the value is 1. Othersise the value is 0.
+
+EQUAL = '<equal>' XXXTERM1 XXXTERM2 '</equal>'
+
+;; If XXX1 equals to XXX2, the value is 1. Otherwise the value is 0.
+;; The equality of terms is decided as below:
+;; INT: INT1 equals to INT2 iff they contain the same integer values.
+;; STR: STR1 equals to STR2 iff they contain strings of the same characters.
+;; SYM: SYM1 equals to SSYM2 iff they contain the same symbol.
+;; LIST: LIST1 equals to LIST2 iff they have the same length, and
+;; the Nth element of LIST1 equals to the Nth element of LIST2.
+
+MATCH = '<match>' XXXTERM1 XXXTERM2 <'/match>'
+
+;; If XXX1 matches with XXX2, the value is 1. Otherwise the value is
+;; 0. Two terms match as below:
+;; INT: INT1 matches with INT2 iff they contain the same integer values.
+;; STR: STR1 matches with STR2 iff STR1's string is a valid regular
+;; expression matching with STR2's string
+;; SYM: SYM1 matches with SSYM2 iff they contain the same symbol.
+;; LIST: LIST1 matches with LIST2 iff LIST1 is not longer than
+;; LIST2, and Nth element of LIST1 equals to Nth element of LIST2.
+;; ERROR: ERROR1 matches with ERROR2 iff ERROR1's error type is
+;; <symbol/> or is the same as ERROR2's error type.
+
PROGN = '<progn>' TERM * '</progn>'
IF = '<if>' TERM TERM TERM ? '</if>'
WHEN = '<when>' TERM TERM * '</when>'
COND = '<cond>' LIST + '</cond>'
LOOP = '<loop>' TERM + '</loop>'
WHILE = '<while>' TERM + '</while>'
-FOREACH = '<foreach vname="' VNAME '">' TERM + '</foreach>'
+FOREACH = '<foreach vname="' VNAME '">' [STRTERM | LISTTERM] TERM + '</foreach>'
BREAK = '<break>' TERM ? '</break>'
RETURN = '<return>' TERM ? '</return>'
QUOTE = '<quote>' TERM '</quote>'
+
+CATCH = '<catch>' [ SYMBOL | ERROR ] TERM + '</catch>'
+ | '<catch vname="' VNAME '">' [ SYMBOL | ERROR ] TERM + '</catch>'
+
+;; Evaluate TERMs one by one until a term matching with the specified
+;; SYMBOL or ERROR is thrown by <throw/>. If thrown, the value is 1,
+;; otherwise the value is 0. If VNAME is specified, its value is set
+;; to the last evaluated term. It is the value of <throw/> if thrown.
+
+THROW = '<throw>' SYMBOL XXXTERM ? '</throw>'
+ | '<throw>' ERROR '</throw>'
+
+;; Throw to the catch for SYMBOL or ERROR. The value is XXXTERM (if
+;; any) or SYMBOL in the first form, and ERROR in the second form.
+
EVAL = '<eval>' TERM '</eval>'
-TYPE = '<type>' TERM '</type>'
+
+TYPE = '<type>' XXXTERM '</type>'
+
+;; The value is SYM representing the type of XXXTERM as below:
+;; INT: the type is <symbol>integer</symbol>
+;; STR: the type is <symbol>string</symbol>
+;; SYM: the type is <symbol>symbol</symbol>
+;; LIST: the type is <symbol>list</symbol>
+;; ERROR: the type is <symbol>error</symbol>