CoCoA:Grammar

Base grammar

A few rules to start the formal language definition.

PROGRAM ::= $\langle$COMMAND$\rangle$ | $\Lambda$

COMMAND ::= HELP_QUERY newline
	| PACKAGE_DECL
	| FUNCTION_DECL
	| STATEMENT;

HELP_QUERY ::= ? $\langle$*$\rangle$

PACKAGE_DECL ::= Package PACKAGE_ID $\langle$FUNCTION_DECL$\rangle$ End${\big [}$Package${\big ]}$

FUNCTION_DECL ::= Define IDENTIFIER( PARAMS ) STATEMENTS End${\big [}$Define${\big ]}$
	| Define Internal IDENTIFIER( PARAMS );
	| Define External IDENTIFIER( PARAMS );

PARAMS ::= $\langle$PARAM ,$\rangle$

PARAM ::= ${\big [}$TYPE${\big ]}$ IDENTIFIER

STATEMENTS ::= $\langle$STATEMENT ;$\rangle$

STATEMENT ::= $\Lambda$
	| ASSIGNMENT
	| EXPRESSION
	| FUNCTION_CALL
	| Return ${\big [}$EXPRESSION${\big ]}$
	| Print EXPRESSIONS
	| PrintLn ${\big [}$EXPRESSIONS${\big ]}$
	| If EXPRESSION Then STATEMENTS ${\big [}$ELSE_LIST${\big ]}$ End${\big [}$If${\big ]}$
	| While EXPRESSION Do STATEMENTS End${\big [}$While${\big ]}$
	| Repeat STATEMENTS Until EXPRESSION
	| For IDENTIFIER := EXPRESSION To EXPRESSION ${\big [}$Step EXPRESSION${\big ]}$
		Do STATEMENTS End${\big [}$For${\big ]}$
	| ForEach IDENTIFIER In EXPRESSION Do STATEMENTS End${\big [}$ForEach${\big ]}$
	| Break
	| Block STATEMENTS End${\big [}$Block${\big ]}$
	| Declare ${\big [}$TYPE${\big ]}$ $\langle$IDENTIFIER ,$\rangle$
	| Delete $\langle$IDENTIFIER ,$\rangle$
	| Quit

ASSIGNMENT ::= LEFT_EXPRESSION := EXPRESSION

LEFT_EXPR ::= IDENTIFIER
	| LEFT_EXPR.IDENTIFIER
	| LEFT_EXPR.[$\langle$EXPRESSION ,$\rangle$]

FUNCTION_CALL ::= FUNCTION_ID( $\langle$EXPRESSION ,$\rangle$ )

FUNCTION_ID ::= IDENTIFIER | EXPRESSION.IDENTIFIER | PACKAGE_ID.IDENTIFIER