CoCoA:Grammar

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Revision as of 15:38, 23 June 2007 by Fran (talk | contribs)

Base grammar

A few rules to start the formal language definition.

PROGRAM ::= COMMAND | 
COMMAND ::= HELP_QUERY newline
   | COMMENT
   | PACKAGE_DECL
   | FUNCTION_DECL
   | STATEMENT;
HELP_QUERY ::= ? *
COMMENT ::= -- * newline
   | // * newline
   | /* * */
PACKAGE_DECL ::=
     Package PACKAGE_ID
       EXPORT_DECL ;
       VARIABLE_DECL ;
       FUNCTION_DECL
     EndPackage
EXPORT_DECL ::= Export IDENTIFIER ,;
VARIABLE_DECL ::= Declare TYPE IDENTIFIER ,;
FUNCTION_DECL ::=
     Define IDENTIFIER( PARAMS ) STATEMENTS EndDefine
   | Define IDENTIFIER( PARAMS ) BuiltIn
   | Define IDENTIFIER( PARAMS ) PlugIn
PARAMS ::= PARAM ,
PARAM ::= TYPE IDENTIFIER
STATEMENTS ::= STATEMENT ;
STATEMENT ::= 
   | ASSIGNMENT
   | EXPRESSION
   | FUNCTION_CALL
   | Return EXPRESSION
   | Print EXPRESSIONS
   | PrintLn EXPRESSIONS
   | If EXPRESSION Then STATEMENTS ELSE_LIST EndIf
   | While EXPRESSION Do STATEMENTS EndWhile
   | Repeat STATEMENTS Until EXPRESSION
   | For IDENTIFIER := EXPRESSION To EXPRESSION Step EXPRESSION
   	Do STATEMENTS EndFor
   | ForEach IDENTIFIER In EXPRESSION Do STATEMENTS EndForEach
   | Break
   | Block STATEMENTS EndBlock
   | VARIABLE_DECL
   | Delete IDENTIFIER ,
   | Quit
ASSIGNMENT ::= LEFT_EXPRESSION := EXPRESSION
LEFT_EXPR ::= IDENTIFIER
	| LEFT_EXPR.IDENTIFIER
	| LEFT_EXPR.[EXPRESSION ,]
FUNCTION_CALL ::= FUNCTION_ID( EXPRESSION , )
FUNCTION_ID ::= IDENTIFIER | EXPRESSION.IDENTIFIER | PACKAGE_ID.IDENTIFIER