CoCoA:Grammar

From ApCoCoAWiki

Base grammar

A few rules to start the formal language definition. (They will slowly get more readable as soon as I get confidence with the wiki)

PROGRAM ::= <COMMAND> | 
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/External] IDENTIFIER(PARAMS)
PARAMS ::= <PARAM ,>
PARAM ::= [TYPE] IDENTIFIER
STATEMENT ::= 
	| 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