Dogma - Condition Syntax

Condition Syntax

Condition syntax is the language used for conditions.

The following formulas can be arranged into expressions with parentheses and boolean operators, where the represent selectors or values (see right column for details).

<NODE> enters location <LOCATION>
<NODE> is in location <LOCATION>
<NODE> exits location <LOCATION>

<NODE> enters view <CAMERA>
<NODE> is in view <CAMERA>
<NODE> exits view <CAMERA>

<PERSON> enters view <CAMERA>
<PERSON> is in view <CAMERA>
<PERSON> exits view <CAMERA>

unidentified person enters view <CAMERA>
unidentified person exits view <CAMERA>

<LANDMARK> enters view <CAMERA>
<LANDMARK> exits view <CAMERA>

<NODE> enters comms range
<NODE> is in comms range
<NODE> exits comms range

time since last seen <NODE> <COMPARATOR> <COUNT> <TIME-INTERVAL-UNIT>
time since last seen <LANDMARK> <COMPARATOR> <COUNT> <TIME-INTERVAL-UNIT>
time since last seen <PERSON> <COMPARATOR> <COUNT> <TIME-INTERVAL-UNIT>

<SENSOR> value becomes <COMPARATOR> <FLOAT>
<SENSOR> value is <COMPARATOR> <FLOAT>

<SENSOR> value enters range <FLOAT> to <FLOAT>
<SENSOR> value is in range <FLOAT> to <FLOAT>

Expressions

Expressions are formed when condition formulas are combined with the following operators:

• and
• or
• (
• )

Examples:

• default.me enters location #garden and #lennart is in #garden
• ( default.me enters location #garden and #lennart is in #garden) or #other_robot enters comms range

Selectors

Selectors will match zero or more items of the type specified. For example, <CAMERA> could be "#mycamera", "#mycam1,#mycam2" or * to denote a specific camera, a list of specific cameras, or any camera respectively.

If there is a typo or the item you want does not exist, the selector will return 0 items and disable the condition it was part of.

Types

The following items can be selected:

• Node
• Person
• Landmark
• Location
• Sensor

Name

Examples:

• "#golem" - Select node identified by name
• "#kitchen" - Select landmark identified by name
• "#lennart" - Select person identified by nickname
• "#mycam" - Select camera identified by name
• "#mythermometer" - Select thermometer sensor identified by name

ID

Example:

• "#57234i747293847923487" - Select item identified by automatically assigned unique ID

List

Example:

• "#mycam1, #mycam2" - Select camera identified by either of two specified names

Wildcard

Examples:

• * - Select all/any item

Default

Examples:

• "default.me" - Select local (ourself) node (node)
• "default.front" - Select the default front-facing camera (camera)
• "default.back" - Select the default back-facing camera (camera)
• "default.temp" - Select the default thermometer (sensor)

Values

Values are specified in placeholders just like selectors, but they represent literal values or enums.

Count

Valid values are all unsigned integers up to 2^64.

Time Interval Unit

Valid values are:

• Y - Years
• M - Months
• W - Weeks
• D - Days
• h - Hours
• m - Minutes
• s - Seconds
• ms - Milliseconds
• u - Microseconds
• n - Nanoseconds

Comparator

Valid values are:

• > - Greater than
• < - Less than
• >= - Greater than or equal
• <= - Less than or equal
• == - Equal
• != - Not equal