Syntax Diagrams

The syntax of PSPP commands is presented in this manual with syntax diagrams.

A syntax diagram is a series of definitions of "nonterminals". Each nonterminal is defined its name, then ::=, then what the nonterminal consists of. If a nonterminal has multiple definitions, then any of them is acceptable. If the definition is empty, then one possible expansion of that nonterminal is nothing. Otherwise, the definition consists of a series of nonterminals and "terminals". The latter represent single tokens and consist of:

• KEYWORD
  Any word written in uppercase is that literal syntax keyword.

• number
  A real number.

• integer
  An integer number.

• string
  A string.

• var-name
  A single variable name.

• =, /, +, -, etc.
  Operators and punctuators.

• .
  The end of the command. This is not necessarily an actual dot in the syntax file (see Forming Commands).

Some nonterminals are very common, so they are defined here in English for clarity:

• var-list
  A list of one or more variable names or the keyword ALL.

• expression
  An expression.

The first nonterminal defined in a syntax diagram for a command is the entire syntax for that command.