Predicate Functions

Spectre predicate functions determine whether an expression is true or false and return a boolean value.

A summary function that returns true if the condition is true on all rows.
all(condition : boolean) : boolean

For example:

all(value("Patient Type") = "Inpatient") returns true if every patient in the current working set is an inpatient.

Two variants exist: one for multiple arguments and one for a single argument.
 
The multiple argument and() is shorthand for a sequence of binary and operations.
and(value1 : boolean, value2 : boolean, ... : boolean) : boolean

For example:

`and(true, false, true)` returns false

`and(true, true, true)` returns true

`and(value("Class")="Sedative",value("Schedule")="IV") returns true for sedatives in schedule 4

 

The single argument and() is a summary function that returns true if the condition is true on all rows. NOTE: This variation is deprecated—use the binary AND operator instead.
and(condition : boolean) : boolean

For example:

`and(value("Drug Class") = "Sedative")` returns true if all drug classes in the current working set are a sedative

 

Simplifies to the named-group predicate for the specified dimension and group name.
group(dimension : string, groupname : string) : boolean

For example:

Assuming the following:

dimension "State" {

group "New England" "ME" "VT" "NH" "MA" "CT" "RI"

}

Then`group("State", "New England")` when "State" is "ME", returns true; when "State" is "TX", returns false.

Returns whether or not the specified value is an error value.
NOTE: This function is considered deprecated. The recommendation is to use the is_unknown function instead.
is_error(value : any) : boolean
Returns whether or not the specified value is in the subsequent list of values.
is_in(candidate : any, value1 : any, value2 : any, ... : any) : boolean

For example:

`is_in("green", "red", "green", "blue")` returns true

`is_in("yellow", "red", "green", "blue")` returns false

Shorthand for is_in on a delimited list of strings.
is_in_list(candidate : string, value_list : string, delimiter : string) : boolean

For example:

`is_in_list("green", "red, green, blue")` returns true

`is_in_list("green", "red|green|blue", "\\\\|")` returns true

`is_in_list("yellow", "red, green, blue")` returns false

Returns whether or not the specified value is a null value.
is_null(value : any) : boolean

For example:

is_null(value("Cost")) returns false if the Cost column has data

`is_null("")` returns true

`is_null(0)` returns false

NOTE:

  • Do not test for a null with string(value("Date")) = ""; instead use is_null(value("Date")).
  • In general, do not test for null with `string(...) = ""` ; instead use `isnull(...)`.
Returns whether or not the specified value is an unknown value.
is_unknown(value : any) : boolean
Returns whether or not the specified value is a null value.
isnull(value : any) : boolean

For example:

isnull(value("Cost")) returns false if the Cost column has data

`isnull("")` returns true

`isnull(0)` returns false

NOTE:

  • Do not test for a null with string(value("Date")) = ""; instead use isnull(value("Date")).
  • In general, do not test for null with `string(...) = ""` ; instead use `isnull(...)`.
Two variants exist: one for multiple arguments and one for a single argument.
 
The multiple argument or() is shorthand for a sequence of binary or's.
or(value1 : boolean, value2 : boolean, ... : boolean) : boolean

For example:

`or(false, true, false)` returns true

`or(false, false, false)` returns false

 

The single argument or() is a summary function that returns true if the condition is true on at least one row. NOTE: This variation is deprecated—use the binary OR operator instead.
or(condition : boolean) : boolean
 
A summary function that returns true if the condition is true on at least one row.
some(condition : boolean) : boolean

For example:

some(year(value("Ship Date")) = 2017) returns true if any record in the current working set has a Ship Date in 2017

A function that creates the opposite boolean result of its condition.

not(condition : boolean) : boolean

The not() function is not an actual function. It is parsed as a NOT unary operator and does not need to be written as a function. For example:

not(value("Year") = 2017) is the same as not value("Year") = 2017. If the value referenced is 2017, the function returns false, otherwise the function returns true.

See also: Alphabetized Functions for Spectre.