自從做好了Vczh Free Script之后，對于λ-calculus的熱情還在，對于未實現(xiàn)lazy evaluation也耿耿于懷。因此又設計了一門類似Haskell的語言來（在語法上模仿了不少），本意是既能享受到lazy evaluation所帶來的優(yōu)美的表現(xiàn)形式，又能將這門語言當腳本而不是單純的程序語言使用。不過將來會演變成什么就暫時不管了。現(xiàn)在貼出該語言的語法的形式描述，做備忘錄之用，或有懇請同行斧正之意。

LAZY_PROGRAM is

    MODULE_DECLARATION

 

--------------------------------------

 

MODULE_DECLARATION is

    module MODULE_NAME exports {FUNCTION_NAME}+ where {DECLARATION}+ end;

 

DECLARATION is

    MODULE_DECLARATION

    IMPORT_DECLARATION

    TYPE_DECLARATION

    CLASS_DECLARATION

    INSTANE_DECLARATION

    FUNCTION_HEAD_DECLARATION

    FUNCTION_BODY_DECLARATION

 

--------------------------------------

 

IMPORT_DECLARATION is

    import MODULE_NAME{.MODULE_NAME};

 

--------------------------------------

 

TYPE_DECLARATION is

    type TYPE_NAME {TYPE_NAME}[= TYPE_DESCRIPTION];

 

SIMPLE_TYPE_DESCRIPTION is

    "(" TYPE_DESCRIPTION ")"

    TYPE_NAME

 

TYPE_DESCRIPTION is

    "(" TYPE_DESCRPTION ")"

    TYPE_NAME {SIMPLE_DESCRIPTION}

    TYPE_CONSTRUCTOR {SIMPLE_TYPE_DESCRIPTION}+

    TYPE_DESCRIPTION -> TYPE_DESCRIPTION

    TYPE_DESCRIPTION "|" TYPE_DESCRIPTION

 

--------------------------------------

 

CLASS_DECLARATION is

    class CLASS_NAME TYPE_NAME [inherits {CLASS_NAME}+] where {FUNCTION_HEAD_DECLARATION|FUNCTION_BODY_DECLARATION}+ end;

 

--------------------------------------

 

INSTANCE_DECLARATION is

    instance CLASS_NAME TYPE_NAME [where {FUNCTION_BODY_DECLARATION}+ end];

 

--------------------------------------

 

FUNCTION_HEAD_DECLARATION is

    FUNCTION_NAME :: {PREREQUISITE,}TYPE_DESCRIPTION;

 

PREREQUISITE is

    [CLASS_NAME] TYPE_NAME

 

FUNCTION_BODY_DECLARATION is

    FUNCTION_NAME {LEFT_VALUE} = (EXPRESSION | linking <string>);

 

--------------------------------------

 

LEFT_VALUE is

    VALUE_NAME

    LEFT_VALUE:VALUE_NAME

    "(" LEFT_VALUE{,LEFT_VALUE} ")"

    "[" [LEFT_VALUE{,LEFT_VALUE}] "]"

    TYPE_CONSTRUCTOR {LEFT_VALUE}+

    "(" LEFT_VALUE ")"

 

EXPRESSION is

    VALUE

    VALUE_NAME

    EXPRESSION:EXPRESSION

    "(" EXPRESSION{,EXPRESSION} ")"

    "[" [EXPRESSION{,EXPRESSION}] "]"

    TYPE_CONSTRUCTOR {EXPRESSION}+

    EXPRESSION EXPRESSION

    "(" OPERATOR_NAME EXPRESSION ")"

    "(" EXPRESSION OPERATOR_NAME ")"

    FUNCTION_NAME

    EXPRESSION OPERATOR EXPRESSION

    "[" EXPRESSION "|" [[LEFT_VALUE <- ]EXPRESSION{,[LEFT_VALUE <- ]EXPRESSION}] "]"

    case EXPRESSION of {LEFT_VALUE:EXPRESSION}+ end

    do {([LEFT_VALUE = ]EXPRESSION | LEFT_VALUE::TYPE_DESCRIPTION);}+ end

    EXPRESSION [where {FUNCTION_HEAD_DECLARATION | FUNCTION_BODY_DECLARATION}+ end]

    \{LEFT_VALUE}+ -> "(" EXPRESSION ")"

 

--------------------------------------

 

MODULE_NAME is

    <identifier>

 

FUNCTION_NAME is

    <identifier>

    "(" OPERATOR ")"

 

TYPE_NAME is

    <identifier>

 

TYPE_CONSTRUCTOR is

    <identifier>

 

CLASS_NAME is

    <identifier>

 

VALUE_NAME is

    <identifier>

 

VALUE is

    <identifier>

    <constant>

 

OPERATOR_NAME is

    "(" OPERATOR ")"

    $ <identifier> $

 

OPERATOR is

    +

    -

    *

    /

    \

    %

    &&

    ||

    ^

    !

    <

    >

    <=

    >=

    ==

    !=

    >>=

    >>

    !!