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Annotation of researchv10no/cmd/sml/doc/refman/direct.tex, revision 1.1

1.1     ! root        1: \chapter{Directives}
        !             2: Directives are included in ML as (syntactically) a subclass of declarations.
        !             3: They possess scope, as do all declarations.  The directives
        !             4: \begin{quote}
        !             5: \verb"infix" {\it d} ${\bf id}_1$ \underline{\ \ \ } ${\bf id}_n$
        !             6: 
        !             7: \verb"infixr" {\it d} ${\bf id}_1$ \underline{\ \ \ } ${\bf id}_n$
        !             8: \end{quote}
        !             9: introduce infix status for the identifiers  ${\bf id}_1$  through ${\bf id}_n$.
        !            10: The digit $d$ (optional, with a default of 0) determines the
        !            11: precedence, and an infixed identifier associates to the left if
        !            12: introduced by \verb"infix", and to the right if introduced by
        !            13: \verb"infixr".  Different infixed operators of equal precedence
        !            14: associate to the left.  As indicated in Appendix~\ref{grammar}, the precedence
        !            15: of infixed application is just weaker than that of application.
        !            16: 
        !            17: The directive
        !            18: \begin{quote}
        !            19: \verb"nonfix" ${\bf id}_1$ \underline{\ \ \ } ${\bf id}_n$
        !            20: \end{quote}
        !            21: cancels infix status for the named identifiers.
        !            22: 
        !            23: While an identifier has infix status, each occurrence of it (as a
        !            24: value variable or as a constructor) must be infixed or else preceded
        !            25: by \verb"op".  Note that this includes occurrences of the identifier
        !            26: within patterns, even binding occurrences of variables.
        !            27: 
        !            28: Several standard functions and constructors have infix status (see
        !            29: Appendix~\ref{grammar}) with precedence; these are all left associative except
        !            30: ``\verb"::"''.

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