@cindex language, PSPP
@cindex PSPP, language
-@quotation
-@strong{Please note:} PSPP is not even close to completion.
-Only a few statistical procedures are implemented. PSPP
-is a work in progress.
-@end quotation
-
This chapter discusses elements common to many PSPP commands.
Later chapters will describe individual commands in detail.
Strings can be concatenated using @samp{+}, so that @samp{"a" + 'b' +
'c'} is equivalent to @samp{'abc'}. Concatenation is useful for
-splitting a single string across multiple source lines. The maximum
-length of a string, after concatenation, is 255 characters.
+splitting a single string across multiple source lines.
Strings may also be expressed as hexadecimal, octal, or binary
character values by prefixing the initial quote character by @samp{X},
that command being considered part of the previous command.
The period terminating the end of a command is optional but recommended.
-In interactive mode, each command must either be terminated with a period,
-or an empty line must follow the command.
-The use of (@samp{+} and @samp{@minus{}} as continuation characters is not
+In interactive mode, each command must be terminated with a period
+or by a blank line.
+The use of @samp{+} and @samp{@minus{}} as continuation characters is not
permitted.
@node Types of Commands
Variables, whether numeric or string, can have designated
@dfn{user-missing values}. Every user-missing value is an actual value
for that variable. However, most of the time user-missing values are
-treated in the same way as the system-missing value. String variables
-that are wider than a certain width, usually 8 characters (depending on
-computer architecture), cannot have user-missing values.
+treated in the same way as the system-missing value.
For more information on missing values, see the following sections:
@ref{Variables}, @ref{MISSING VALUES}, @ref{Expressions}. See also the
@item Width
(string variables only) String variables with a width of 8 characters or
fewer are called @dfn{short string variables}. Short string variables
-can be used in many procedures where @dfn{long string variables} (those
+may be used in a few contexts where @dfn{long string variables} (those
with widths greater than 8) are not allowed.
-Certain systems may consider strings longer than 8
-characters to be short strings. Eight characters represents a minimum
-figure for the maximum length of a short string.
-
@item Position
Variables in the dictionary are arranged in a specific order.
@cmd{DISPLAY} can be used to show this order: see @ref{DISPLAY}.
The maximum width for time and date formats is 40 columns. Minimum
input and output width for each of the time and date formats is shown
below:
+
@float
@multitable {DATETIME} {Min. Input Width} {Min. Output Width} {4-digit year}
@headitem Format @tab Min. Input Width @tab Min. Output Width @tab Option
@dfn{start symbol}. The start symbol defines the entire syntax for
that command.
@end itemize
-@setfilename ignored