Expressions

<expr>

An expression is one of: operand literal integer (can be used as string) or string (e.g. “LSOA”) variable or property, e.g. myvar or object.property list element reference, e.g. object.property[index] call to sub-test, e.g. myrule(3) parenthesised sub-expression, e.g. (a + b) the keyword fail which evaluates to a string which is the fail message from the most recent failing sub-test. This can be used to compose fail messages in higher level tests. infix operator expression, e.g. a + b or c > d prefix operator with operand parameter, i.e. not, len or marked

Boolean valued expressions which evaluate to true or false:

<expr1> < <expr2>	integer <expr1> is less than integer <expr2>
<expr1> > <expr2>	integer <expr1> is greater than integer <expr2>
<expr1> >= <expr2>	integer <expr1> is greater than or equal to integer <expr2>
<expr1> <= <expr2>	integer <expr1> is less than or equal to integer <expr2>
<expr1> == <expr2>	integer <expr1> is equal to integer <expr2>
<expr1> != <expr2>	integer <expr1> is not equal to integer <expr2>
<expr1> eq <expr2>	string <expr1> is equal to string <expr2>
<expr1> ne <expr2>	string <expr1> is not equal to string <expr2>
<expr1> && <expr2>	Logical “and” of two boolean expressions. Shortcut behaviour: only evaluate <expr2> if <expr1> is true.
<expr1> || <expr2>	Logical “or” of two boolean expressions. Shortcut behaviour: only evaluate <expr2> if <expr1> is false.
not <expr>	Invert the truth value of boolean valued <expr>
marked <expr>	Has the cell been marked in this table test?
<test>( <expr> [,<expr> ...] )	Evaluate the named test using the supplied parameters resulting in “true” if the test passes and “false” if it fails.
<src> sourceof <map>	True if the variable named <src> is a source of mapping variable named <map>. Both <src> and <map> must be a string valued expression which is a valid variable name. A variable is also a source of itself.
<map> mapof <src>	True if variable <map> is a mapping (directly or indirectly) of variable <src>. Both <map> and <src> can be a reference to a variable in a list or a literal string variable name. A variable is never a map of itself.
qin <query_specification>	True if the current query is a subset of the <query_specification>. This means that a query which matches any subset of the specified variable combinations in any order will cause the operator to evaluate to true. <query_specification> is a comma separated list of variables or sets of variables. A single variable in the query is specified as a literal string (e.g. "AGE") or as a set of possible variables enclosed by parentheses and separated by commas. Furthermore each variable literal can be replaced by a parenthesised expression consisting of a literal string followed by sourceof which is an alias for all variables which have that variable as a (direct or indirect) source, including itself, e.g.: ("var_name" sourceof) Example: qin ("A", "B"), ("C" sourceof), "E" If D was a mapping of C then the above expression returns true for all of the following queries: “A”, “C”, “E” “B”, “C”, “E” “A”, “D”, “E” “B”, “D”, “E” and any subset of any of these, i.e. “A”, “C” “A”, “E” “C”, “E” “B”, “C” “B”, “E” “A”, “D” “D”, “E” “B”, “D” as well as all of the five univariate queries. Note that, as mentioned above, the queries will match in any order. So, for example, both: “E”, “A” “B”, “E”, “D” would also match.

Integer valued expressions:

<expr1> * <expr2>	<expr1> multiplied by <expr2>
<expr1> / <expr2>	<expr1> divided by <expr2>. Note that if <expr1> is less than <expr2> then the result will be zero.
<expr1> % <expr2>	<expr1> modulus <expr2>
<expr1> + <expr2>	Sum of <expr1> and <expr2>
<expr1> - <expr2>	<expr1> minus <expr2>
len <list>	Length of list <list>

Reference expressions which evaluate to an object:

<list>[<index>]

Return item at zero based position <index> in list <list>

String valued expressions:

<expr> & <expr> [& <expr> ...]

Concatenate strings