CoCoA:Grammar

Base grammar

A few rules to start the formal language definition.

PROGRAM ::= $⟨$COMMAND$⟩$ | $\mathrm{\Lambda }$

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

HELP_QUERY ::= ? $⟨$*$⟩$

PACKAGE_DECL ::= Package PACKAGE_ID $⟨$FUNCTION_DECL$⟩$ End$[$Package$]$

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

PARAMS ::= $⟨$PARAM ,$⟩$

PARAM ::= $[$TYPE$]$ IDENTIFIER

STATEMENTS ::= $⟨$STATEMENT ;$⟩$

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