ThingTalk Reference Manual

Types

  • Boolean: true or false.

  • String: any string; strings do not have to be valid UTF-16, but they are stored as UCS-2 and cannot have embedded NUL characters.

  • Enum(e1, e2, ...): enumerated type, having values e1, e2, etc. (e.g. Enum(on,off) represents the possibility of being on or off). In Javascript, this is represented as a String (the enum value).

  • Entity(...): an identifier to an object; the type is parametrized with the actual entity type. An entity has a value, and an optional display property that represents the user visible name of the object. In JavaScript, entities can be represented as simple strings, or using the Thingpedia.Value.Entity class. For example, the stock ID of Google can be represented as:

    new Thingpedia.Value.Entity("goog", "tt:stock_id", "Alphabet Inc.")
    

    The following entity types have special meaning to the semantic parser:

    • Entity(tt:picture): a picture (identified by its URL)
    • Entity(tt:hashtag): a hashtag (a word preceded by the # sign)
    • Entity(tt:username): a username (a word preceded by an @ sign)
    • Entity(tt:path_name): a path or file name
    • Entity(tt:url): a URL (not necessarily pointing to a picture)
    • Entity(tt:phone_number): a phone number
    • Entity(tt:email_address): an email address
    • Entity(tt:device): a Thingpedia device type (e.g. com.twitter)
    • Entity(tt:function): a Thingpedia function identifier, composed of device type + : + function name (e.g. com.twitter:post)

    The full list of entity types is available at ThingTalk Entity Types. Custom Entity types can be defined, using a prefix other than tt:.

  • Number: IEEE754 double precision floating point.

  • Measure(...): same as Number, but parametrized by one of the unit types; literals of Measure type have automatic conversion to and from the most common unit types, and can be written as a sum of multiple terms (e.g. 6ft + 3in). In Javascript, this is represented as a number, to be interpreted in the base unit of the Measure type. For example, 6ft + 3in will be converted to 1.905m, and will be interpreted as 1.905 in Javascript.

  • Currency: a Number with a unit. This differs from Measure because the unit is not normalized, and is accessible at runtime. In JavaScript this type is represented as a number (the unit will default to US dollar), or using the Thingpedia.Value.Currency type. For example:

    new Thingpedia.Value.Currency(100, 'usd')
    
  • Date: a specific point in time (date and time). In JavaScript this is represented with the Date class.

  • Time: a time of day without date. In JavaScript this is an object of class Thingpedia.Value.Time with .hour, .minute and .second property. For example, 7 PM is represented as:

    new Thingpedia.Value.Time(19, 0, 0) 
    
  • Location: a specific point on the Earth surface, as a pair of latitude and longitude, and optional name. In JavaScript this is an object of class Thingpedia.Value.Location. It has 3 properties: the latitude, the longitude, and the name of the location (optional). For example, we work here:

    new Thingpedia.Value.Location(37.43, -122.1733, "Gates Computer Science, Stanford").
    
  • Array(elem): an ordered sequence of values of the same type; arrays are compared by value (i.e., two arrays are equal if the have the same size and are pair wise equal)

  • (t1, t2, t3, ...): a Tuple type, contains a finite number of heterogenous values; use (v,) (note the comma) to construct a tuple with one element, but (t) to denote the tuple type with arity 1

Filter operators

  • !, &&, ||: logical connectives NOT, AND and OR

  • >=, <=: comparison operators; if applied to Strings, values are compared lexicographically

  • ==, !=: equality, inequality; note that the equality operator is special when used at the top level of a condition (see below for Builtin predicates); equality for strings is case sensitive.

  • =~: "substring", returns true if the right hand side occurs as a substring of the left hand side; both arguments must be Strings. Substring is case insensitive.

  • ~=: "reversed substring", returns true if the left hand side is a substring of the right hand side

  • contains(array, elem): array containment; returns true if at least one element of the array compares equal (according to ==) to the passed element

  • in_array(elem, array): reversed array containment

  • starts_with(string, prefix), ends_with(string, suffix), prefix_of(prefix, string), suffix_of(suffix, string): returns true if prefix is a case-insensitive prefix (resp. suffix) of string

Literal value syntax

  • $undefined: the value is unspecified and must be slot filled

  • $event: the description of the last result

  • $event.type: the type (function identifier) of the last result

  • $event.program_id: the current program id

  • enum(x): the enumerated value x (e.g. enum(on) or enum(off))

  • makeDate(): current time (of type Date)

  • makeDate(yyyy, mm, dd, HH, MM, SS): the specified time; HH, MM and SS can be omitted

  • makeDate(unix_timestamp): unix timestamp in milliseconds since the epoch

  • date [+-] offset: relative date; offset is a literal of Measure(ms) type; e.g. makeDate() - 1h = "1 hour ago"

  • start_of(hour|day|week|month|year), end_of(hour|day|week|month|year): relative date; e.g. start_of(day) = "today" (at midnight)

  • true/false: boolean

  • number followed by unit: Measure literal; space is not allowed between the number and the unit

  • makeCurrency(num, code): Currency literal; code is the 3 letter currency code, lowercase; e.g. makeCurrency(25, usd)

  • makeTime(hour, minute, second): Time literal; second can be omitted and defaults to 0

  • makeLocation(lat, lon, display): Location literal; display can be omitted

  • $context.location.home, $context.location.work, $context.location.current_location: predefined locations

  • "...": String literal

  • "..."^^type, "..."^^type("display"): Entity literal

  • [...]: Array literal

Builtin Triggers

  • timer(base : Date, interval : Measure(ms)): interval timer

  • attimer(time : Time): daily timer, fires at the given time

Units of Measure

The following units are valid for the type Measure(...):

  • ms: time (milliseconds)
  • m: distance (meters)
  • mps: speed (meters per second)
  • kg: mass (kilograms)
  • Pa: pressure (Pascal)
  • C: temperature (Celsius)
  • kcal: energy (kilocalories)
  • byte: data size (Byte)

The following units are additionally recognized in measure literals, and implicitly converted to the base unit for all operations.

Unit Base Unit Physical quantity
s (seconds) ms time
min (minutes) ms time
h (hours) ms time
day (days) ms time
week (weeks) ms time
mon (business month = 30 days) ms time
year (business year = 365 days) ms time
km (kilometers) m distance
mm (millimeters) m distance
cm (centimeters) m distance
mi (miles) m distance
in (inches) m distance
kmph (kilometers per hour) mps speed
mph (miles per hour) mps speed
g (grams) kg mass
lb (US pound) kg mass
oz (US ounce) kg mass
bar (bar) Pa pressure
psi (pounds per square inch) Pa pressure
mmHg (millimeters of mercury) Pa pressure
inHg (inches of mercury) Pa pressure
F (Fahrenheit) C temperature
K (Kelvin) C temperature
kJ (kilojoule) kcal energy
KB (1000 bytes) byte data size
KiB (1024 bytes) byte data size
MB (1000 KB) byte data size
MiB (1024KiB) byte data size
GB (1000 MB) byte data size
GiB (1024 MiB) byte data size
TB (1000 GB) byte data size
TiB (1024 GiB) byte data size