Return to standard.tex CVS log

Up to [Research Unix] / researchv10no / cmd / sml / doc / refman

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

1.1     ! root        1: \chapter{Standard bindings}
        !             2: ML provides the record type constructor 
        !             3: $ \verb"{" {\bf lab}_1 \verb":" {\bf ty}_1 , \underline{\ \ \ }
        !             4:  , {\bf lab}_n \verb":" {\bf ty}_n \verb"}"$ for any set 
        !             5: $\{ {\bf lab}_i \} $ of labels and corresponding set 
        !             6: $\{ {\bf ty}_i \} $ of types.  The language also provides the infixed
        !             7: function-type constructor \verb"->".  Otherwise, type constructors
        !             8: are postfixed.  The following are standard:
        !             9: 
        !            10: \begin{description}
        !            11: \item[Type {\em constants} (nullary constructors):]  unit, bool, exn, int,
        !            12: real, string, instream, outstream
        !            13: \item[Unary type constructors:]  list, ref
        !            14: \end{description}
        !            15: 
        !            16: The constructors unit, bool, and list are fully defined by the
        !            17: following assumed declaration
        !            18: \begin{verbatim}
        !            19: infixr 5 ::
        !            20: type unit = {}
        !            21: datatype    bool = true | false
        !            22: datatype  'a list = nil |  :: of {1 : 'a, 2 : 'a list}
        !            23: \end{verbatim}
        !            24: 
        !            25: The word ``unit'' is chosen since the type contains just one value
        !            26: ``\verb"{}"'', the empty record.  This is why it is preferred to the
        !            27: word ``void'' of Algol-68.
        !            28: 
        !            29: The type constants \verb"int", \verb"real", and \verb"string"
        !            30: are equipped with special
        !            31: constants as described in section 2.3.  The type constructor
        !            32: \verb"ref" is for constructing reference types; see
        !            33: Chapter~\ref{reference}.
        !            34: The type constant \verb"exn" is the type of all exceptions, and
        !            35: is a datatype containing an unbounded number of constructors
        !            36: generated by \verb"exception" bindings (see Chapter~\ref{exception}).
        !            37: 
        !            38: 
        !            39: 
        !            40: The initial top-level environment is comprised of a set of standard
        !            41: bindings.  The initial environment is much more extensive than the
        !            42: environment described in {\it The Definition of Standard ML}, and
        !            43: is almost a proper superset.  The differences are:
        !            44: 
        !            45: \begin{itemize}
        !            46: \item All values, types, datatypes, etc. are grouped into structures;
        !            47: these structures are opened in the initial environment so that the
        !            48: names can be used without a structure-name qualification.
        !            49: 
        !            50: \item There are many additional initial bindings, described in 
        !            51: Appendix~\ref{library}.
        !            52: 
        !            53: \item The functions \verb"input" and \verb"output" are curried in Standard
        !            54: ML of New Jersey, e.g. \verb"input: instream->int->string" instead of
        !            55: \verb"input: instream*int->string".
        !            56: 
        !            57: \item The integer functions \verb"+", \verb"-", \verb"div", \verb"mod", 
        !            58: \verb"*", \verb"~", \verb"abs" all raise \verb"Overflow" if the result is out-of-range,
        !            59: rather than \verb"Sum", \verb"Diff", \verb"Div", \verb"Mod", \verb"Prod",
        !            60: \verb"Neg", \verb"Abs", respectively.
        !            61: 
        !            62: \item The integer \verb"div" function rounds toward zero, and \verb"x mod y"
        !            63: is defined as \verb"x-y*(x div y)".
        !            64: 
        !            65: \end{itemize}
        !            66: 
        !            67: Standard ML of New Jersey is distributed with a structure \verb"Standard"
        !            68: that may be loaded into the initial environment to simulate
        !            69: environment described in the {\it Definition}.

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.