work on manual

diff --git a/rust/doc/src/SUMMARY.md b/rust/doc/src/SUMMARY.md
index e8ac7750e66e042d01fd1b588fc45549b62202d9..3a08d45935a6ff0dcaee3af5909ae0e954bec269 100644 (file)
--- a/rust/doc/src/SUMMARY.md
+++ b/rust/doc/src/SUMMARY.md
@@ -37,6 +37,7 @@
     - [Time and Date Functions](language/expressions/functions/time-and-date.md)
     - [Miscellaneous Functions](language/expressions/functions/miscellaneous.md)
     - [Statistical Distribution Functions](language/expressions/functions/statistical-distributions.md)
+  - [System Variables](language/expressions/system-variables.md)
 
 # Command Syntax
 
@@ -74,6 +75,8 @@
   - [ADD FILES](commands/combining/add-files.md)
   - [MATCH FILES](commands/combining/match-files.md)
   - [UPDATE](commands/combining/update.md)
+- [Manipulating Variables](commands/variables/index.md)
+  - [DISPLAY](commands/variables/display.md)
 
 # Developer Documentation
 

diff --git a/rust/doc/src/commands/variables/display.md b/rust/doc/src/commands/variables/display.md
new file mode 100644 (file)
index 0000000..78b5e42
--- /dev/null
+++ b/rust/doc/src/commands/variables/display.md
@@ -0,0 +1,65 @@
+# DISPLAY
+
+The `DISPLAY` command displays information about the variables in the
+active dataset.  A variety of different forms of information can be
+requested.  By default, all variables in the active dataset are
+displayed.  However you can select variables of interest using the
+`/VARIABLES` subcommand.
+
+```
+DISPLAY [SORTED] NAMES [[/VARIABLES=]VAR_LIST].
+DISPLAY [SORTED] INDEX [[/VARIABLES=]VAR_LIST].
+DISPLAY [SORTED] LABELS [[/VARIABLES=]VAR_LIST].
+DISPLAY [SORTED] VARIABLES [[/VARIABLES=]VAR_LIST].
+DISPLAY [SORTED] DICTIONARY [[/VARIABLES=]VAR_LIST].
+DISPLAY [SORTED] SCRATCH [[/VARIABLES=]VAR_LIST].
+DISPLAY [SORTED] ATTRIBUTES [[/VARIABLES=]VAR_LIST].
+DISPLAY [SORTED] @ATTRIBUTES [[/VARIABLES=]VAR_LIST].
+DISPLAY [SORTED] VECTORS.
+```
+
+The following keywords primarily cause information about variables to
+be displayed.  With these keywords, by default information is
+displayed about all variable in the active dataset, in the order that
+variables occur in the active dataset dictionary.  The `SORTED`
+keyword causes output to be sorted alphabetically by variable name.
+
+* `NAMES`  
+  The variables' names are displayed.
+
+* `INDEX`  
+  The variables' names are displayed along with a value describing
+  their position within the active dataset dictionary.
+
+* `LABELS`  
+  Variable names, positions, and variable labels are displayed.
+
+* `VARIABLES`  
+  Variable names, positions, print and write formats, and missing
+  values are displayed.
+
+* `DICTIONARY`  
+  Variable names, positions, print and write formats, missing values,
+  variable labels, and value labels are displayed.
+
+* `SCRATCH`  
+  Variablenames are displayed, for scratch variables only (*note
+  Scratch Variables::).
+
+* `ATTRIBUTES`  
+  Datafile and variable attributes are displayed, except attributes
+  whose names begin with `@` or `$@`.
+
+
+* `@ATTRIBUTES`  
+  All datafile and variable attributes, even those whose names begin
+  with `@` or `$@`.
+
+With the `VECTOR` keyword, `DISPLAY` lists all the currently declared
+vectors.  If the `SORTED` keyword is given, the vectors are listed in
+alphabetical order; otherwise, they are listed in textual order of
+definition within the PSPP syntax file.
+
+For related commands, see *note DISPLAY DOCUMENTS:: and *note DISPLAY
+FILE LABEL::.
+

diff --git a/rust/doc/src/commands/variables/index.md b/rust/doc/src/commands/variables/index.md
new file mode 100644 (file)
index 0000000..1dc0d73
--- /dev/null
+++ b/rust/doc/src/commands/variables/index.md
@@ -0,0 +1,8 @@
+# Manipulating Variables
+
+Every value in a dataset is associated with a
+[variable](../../language/datasets/variables.md).  Variables describe
+what the values represent and properties of those values, such as the
+format in which they should be displayed, whether they are numeric or
+alphabetic and how missing values should be represented.  There are
+several utility commands for examining and adjusting variables.

diff --git a/rust/doc/src/language/expressions/system-variables.md b/rust/doc/src/language/expressions/system-variables.md
new file mode 100644 (file)
index 0000000..1be7460
--- /dev/null
+++ b/rust/doc/src/language/expressions/system-variables.md
@@ -0,0 +1,33 @@
+# System Variables
+
+The system variables described below may be used only in expressions.
+
+* `$CASENUM`  
+  Case number of the case being processed.  This changes as cases are
+  added, deleted, and reordered.
+
+* `$DATE`  
+  Date the PSPP process was started, in format `A9`, following the
+  pattern `DD-MMM-YY`.
+
+* `$DATE11`  
+  Date the PSPP process was started, in format `A11`, following the
+  pattern `DD-MMM-YYYY`.
+
+* `$JDATE`  
+  Number of days between 15 Oct 1582 and the time the PSPP process
+  was started.
+
+* `$LENGTH`  
+  Page length, in lines, in format `F11`.
+
+* `$SYSMIS`  
+  System missing value, in format `F1`.
+
+* `$TIME`  
+  Number of seconds between midnight 14 Oct 1582 and the time the
+  active dataset was read, in format `F20`.
+
+* `$WIDTH`  
+  Page width, in characters, in format `F3`.
+