CoCoA:Grammar

Base grammar

A few rules to start the formal language definition.

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

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 ::= $\mathrm{\Lambda }$
   | 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