Comments
Inferno is a hybrid scripting language created by Plow Technologies that brings powerful real-time scripting capabilities to applications that use it. Think of Inferno as Excel scripting for real-time data.
Below are Inferno’s syntax rules for various operations:
Commenting Syntax
Inferno’s comment types include single-line and multi-line commenting:
'//' for single-line comments
'/…/' for multi-line comments
Numeric Literals
Inferno’s numeric types include integer literals and floating-point literals.
Integer literals represent fixed positive or negative integer values that are nonfractional whole numbers like 300, 43, 777, -234, etc. (within the integer range).
Floating-point literals represent positive or negative fractional values with decimal places, such as 56.43, 2.66, 1204.99, etc.
Integer and Floating Point Syntax Examples
3 // integer literal
-3 // negative integer literal
3.0 // floating-point literal
-3.0 // negative floating-point literal
Arithmetic Syntax
Inferno supports basic arithmetic operations on numeric types meaning that it can be used to perform mathematical calculations such as addition, subtraction, multiplication, and division on numbers. In addition to these basic operations, Inferno also supports more mathematical functions such as logarithms and exponentials. These functions can be useful for more complex calculations.
Here are some examples of basic arithmetic operations and syntax examples in Inferno:
Operation | Operator | Syntax Example | Result |
Add | ‘+’ | 3 + 4 | 7 |
Subtract | ‘-‘ | 3.0 – 2 | 1.0 |
Divide | ‘/’ | 3.0 / 2 | 1.5 |
Multiply | ‘*’ | 3.14* recip 3.14 | 1.0 |
Power | ‘**’ | 1.4** 2.5 | 1.9843134832984438 |
Power (exp,ln) | ‘exp’ ‘ln’ | exp (ln 1) | 1.0 |
Logs | ‘log’ ‘logBase’ | logBase 10 100 | 2.0 |
Logs (exp,ln) | ‘exp’ ‘ln | ln (exp 1) | 1.0 |
Square Root | ‘sqrt’ | sqrt 1.425 | 1.1941939201359381m |
Negation | ‘let x =’ | let x = 1425 in -x | -1425 |
Absolute Val | ‘abs’ | abs (-14.25) | 14.25 |
Modulus | ‘%’ | -3 % 5 | 2 |
Testing
You can use the assert statement to write simple tests in your code.
Assert statements will be removed when the code is run outside the testing environment.
Example:
// user: what does the negation function look like in inferno? // - : {requires negate on 'a} ⇒ 'a → 'a // Negation (unary) on int, double, or timeDiff let negationInt = - (-3) in assert (negationInt == 3) in let negationDouble = - (- 3.0) in assert (negationDouble == 3.0) in let negationTimeDiff = - (Time.hours (-3)) in assert (negationTimeDiff == Time.hours 3) in negationInt |
Array Syntax
A variety of expressions can be used to build complex programs with Array:
Expression | Function | Expression Example | Result |
Array.sum | Calculates the sum of an array, after filtering out the None values. | Array.sum (Array.keepSomes [Some 3.0, None, Some 4.0]) | 0.7 |
Array.findFirstSome | Finds the first element in an array that is not None. | Array.findFirstSome [None, Some 3.0, None, Some 4.0] | A value that represents the found element. |
Array.findLastSome | Finds the last element in an array that is not None. | Array.findLastSome [None, Some 3.0, None, Some 4.0] | A value that represents the found element. |
Array.findFirstAndLastSome | Finds both the first and last element in an array that is not None. | Array.findFirstAndLastSome [None, Some 3.0, None, Some 4.0] | A tuple of two values, each represents the found element |
Fetching Data From OnPing
Expression | Function | Expression Example | Result |
valueAt | Find the value of an input stream at a given time. | valueAt input0 ?now | 0.7 |
latestValue | Finds the latest value from an input stream. | latestValue input0 | 0.8 |
latestValueBefore | Finds the latest value from an input stream before some given time. | latestValueBefore ?now input0 | 0.8 |
Data Formatting
Expression | Function | Expression Example | Result |
truncateTo | Cut off decimals after n values | truncateTo 0 3.1234 | 3 |
Option Syntax
A variety of expressions can be used to build complex programs with Option:
Expression | Function | Expression Example | Result |
Option.map | Maps the given function to the value of the option, if it exists. | Option.map (fun x -> x + 2) (Some 4.0) | A value that represents the result of the mapping operation |
fromOption | Extracts the value of an option, or returns the default if option is None. | fromOption 0 (Some 4.0) | A value of the options or the default value, depending on the value. |
Operator “?” | Returns the value of the option if it exists, or default if option is None. | (Some 4.0) ? 0 | A value of the option or the default value, depending on the option |
Option.reduce | Applies the given binary function to elements of option. Returns the result | Option.reduce (fun d -> d + 2) 0.0 (Some 4.0) | A value that represents the result of the reduction operation. |
Bitwise Operations
Bitwise Operation Expression Example | Result | Function |
0x5 && 0x9 | 1 | Performs a bitwise AND operation on two values. |
0x5 XOR 0x6 | 3 | Performs a bitwise XOR operation on two values. |
!(toWord16 0x1) | 65534 | Performs a bitwise NOT operation on a value. |
testBit (setBit 0x0 3) 3 | vTrue | Sets a bit in a value and then checks if it is set. |
shift 0x1 3 | 8 | Performs a bit shift operation on a value. |
fromWord #false | 0 | Converts a Boolean value to an integer. |
Word Conversion
Word Conversion Expression Example | Result | Function |
toWord16 #true | 1 | Converts a Boolean value to a 16-bit unsigned integer. |
toWord16 (toWord64 77) | 77 | Converts a 64-bit unsigned integer to a 16-bit unsigned integer. |
toWord16 (toWord64 (2**17 + 2)) | 22 | Converts a large 64-bit unsigned integer to a 16-bit unsigned integer. |
toWord32 (toWord64 77) | 77 | Converts a 64-bit unsigned integer to a 32-bit unsigned integer |
toWord32 (toWord64 (2**33 + 5)) | 5 | Converts a large 64-bit unsigned integer to a 32-bit unsigned integer. |
toWord64 (toWord16 (2**62 + 1)) | 1 | Converts a large 16-bit unsigned integer to a 64-bit unsigned integer. |
Word Size Conversion
Word Size Conversion Expression Example | Result | Function |
fromWord (toWord64 (2**62)) | 4611686018427387904 | Converts a large unsigned integer to a signed integer. |
fromWord (toWord32 (262 + 231)) | 2147483648 | Converts a 64-bit unsigned integer to a 16-bit unsigned integer. |
fromWord (toWord16 (231 + 23)) | 8 | Converts a large unsigned integer to a signed integer. |
Data Retrieval
Word Size Conversion Expression Example | Result | Function |
valueAt t input | Some val | Retrieve an approximate value for a data stream at a given time. |
latestValueBefore t input | Some val | Retrieve an approximate value for a data stream at a given time. |
latestInput input | Some val | Retrieve the first value found, which occurred before the default ?now |
Automated Function Reference
Module Base (needs no prefix)
Item | Description |
! : forall 'a . {requires bitlike on 'a} ⇒ 'a → 'a | Complements (switches 0s and 1s) all bits in the argument |
- : forall 'a . {requires negate on 'a} ⇒ 'a → 'a | Negation (unary) on int, double, or timeDiff |
None : forall 'a . option of 'a | Optional type, representing a value which may be undefined. None indicates no value is present and Some v holds a value v To test whether an optional o holds some value, use match ... with and pattern match on o: ~~~ match o with { | Some v -> // use v here | None -> // handle the case where o is None } ~~~ |
Some : forall 'a . 'a → option of 'a | Optional type, representing a value which may be undefined. None indicates no value is present and Some v holds a value v To test whether an optional o holds some value, use match ... with and pattern match on o: ~~~ match o with { | Some v -> // use v here | None -> // handle the case where o is None } ~~~ |
abs : forall 'a . {requires abs on 'a} ⇒ 'a → 'a | Absolute value (sometimes written |x|) on int, double, or timeDiff |
arcCos : double → double | Inverse cosine (trigonometric function) of a double |
arcSin : double → double | Inverse sine (trigonometric function) of a double |
arcTan : double → double | Inverse tan (trigonometric function) of a double |
ceiling : forall 'a . {requires roundable on 'a} ⇒ 'a → int | Ceiling function (rounds up to nearest integer) |
clearBit : forall 'a . {requires bitlike on 'a} ⇒ 'a → int → 'a | Clears the bit at the provided offset (i.e., sets it to 0) |
complementBit : forall 'a . {requires bitlike on 'a} ⇒ 'a → int → 'a | Switches the bit at the provided offset (0 to 1 or vice versa) |
cos : double → double | Cosine (trigonometric function), on double |
cosh : double → double | Hyperbolic cosine (trigonometric function) of a double |
doubleToInt : double → int | Convert double to int |
exp : double → double | Exponential function |
floor : forall 'a . {requires roundable on 'a} ⇒ 'a → int | Floor function (rounds down to nearest integer) |
fromBCD : word64 → option of word64 | Decode a BCD-encoded word64 |
fromOption : forall 'a . 'a → option of 'a → 'a | The fromOption function unwraps an optional value, if given a default value to fall back on in case the value of the optional is None. ~~~inferno fromOption “hi” (Some “hello”) == “hello” fromOption “hi” None == “hi” ~~~ |
fromWord : forall 'a . {requires fromWord on 'a} ⇒ 'a → int | Convert a word to an int |
fst : forall 'a 'b . ('a, 'b) → 'a | Gets the first component of a tuple: fst (x, y) == x |
id : forall 'a . 'a → 'a | The identity function |
intToDouble : int → double | Convert int to double |
latestValue : forall 'a . {implicit now : time} ⇒ series of 'a → option of 'a | Returns the latest value of the parameter, if one exists. |
latestValueAndTime : forall 'a . {implicit now : time} ⇒ series of 'a → option of ('a, time) | Returns the latest value of the parameter (and the corresponding timestamp), if one exists. |
latestValueAndTimeBefore : forall 'a . time → series of 'a → option of ('a, time) | Returns the latest value of the parameter (and the corresponding timestamp) before the given time, if one exists. |
latestValueBefore : forall 'a . time → series of 'a → option of 'a | Returns the latest value of the parameter before the given time, if one exists. |
limit : double → double → double → double | limit l u x = min l (max x u) limits x to be between l and u |
ln : double → double | Natural logarithm |
log : double → double | Logarithm with base 10 |
logBase : double → double → double | Logarithm with base b |
max : forall 'a . {requires order on 'a} ⇒ 'a → 'a → 'a | Maximum function on int, double, word16/32/64, time and timeDiff |
min : forall 'a . {requires order on 'a} ⇒ 'a → 'a → 'a | Minimum function on int, double, word16/32/64, time and timeDiff |
pi : double | Pi (3.14159... :: double), the constant |
random : () → double | A (pseudo)random double |
recip : double → double | Reciprocal fraction |
resolutionToInt : resolution → int |
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round : forall 'a . {requires roundable on 'a} ⇒ 'a → int | round x returns the nearest integer to x (the even integer if x is equidistant between two integers) |
roundTo : int → double → double | roundTo d x rounds x to d decimal places |
setBit : forall 'a . {requires bitlike on 'a} ⇒ 'a → int → 'a | Sets the bit at the provided offset to 1 |
shift : forall 'a . {requires bitlike on 'a} ⇒ 'a → int → 'a | shift x i shifts x left by i bits if i is positive, or right by -i bits otherwise. Right shifts perform sign extension on signed number types (i.e. they fill the top bits with 1 if x is negative and with 0 otherwise) |
sin : double → double | Sine (trigonometric function) of a double |
sinh : double → double | Hyperbolic sine (trigonometric function) of a double |
snd : forall 'a 'b . ('a, 'b) → 'b | Gets the second component of a tuple: snd (x, y) == y |
sqrt : double → double | Square root |
tan : double → double | Tan (trigonometric function), on double |
tanh : double → double | Hyperbolic tangent (trigonometric function) of a double |
testBit : forall 'a . {requires bitlike on 'a} ⇒ 'a → int → bool{#false,#true} | Checks if the bit at the provided offset is set |
toBCD : word64 → word64 | Encode a BCD-encoded word64 |
toResolution : int → resolution |
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toWord16 : forall 'a . {requires toWord16 on 'a} ⇒ 'a → word16 | Convert an int or another word to a word16, dropping bits if necessary |
toWord32 : forall 'a . {requires toWord32 on 'a} ⇒ 'a → word32 | Convert an int or another word to a word32, dropping bits if necessary |
toWord64 : forall 'a . {requires toWord64 on 'a} ⇒ 'a → word64 | Convert an int or another word to a word64 |
truncate : forall 'a . {requires roundable on 'a} ⇒ 'a → int | truncate x returns the integer nearest x between zero and x |
truncateTo : int → double → double | truncateTo d x truncates x to d decimal places |
valueAt : forall 'a . {implicit resolution : resolution} ⇒ series of 'a → time → option of 'a | Returns the value of the parameter in the chunk containing the given time, if it exists. For example, if resolution is 128 (thus chunks are 0-127, 128-255, 256-383, …), and the parameter p has values: ~~~ V: 1.0 | | 3.0 | T: 0 … 120 … 127 128 … 255 256 … 300 … 383 384 … ~~~ then: ~~~inferno open Time in valueAt p (toTime (seconds 128)) == Some 1.0 valueAt p (toTime (seconds 129)) == None valueAt p (toTime (seconds 380)) == Some 3.0 ~~~ |
valueAtOrAdjacent : forall 'a . {implicit resolution : resolution} ⇒ series of 'a → time → option of 'a | Returns the value of the parameter in the chunk containing the given time, if it exists, or in the closest adjacent chunk (previous or next chunk), if it exists. For example, if resolution is 128 (thus chunks are 0-127, 128-255, 256-383, …), and the parameter p has values: ~~~ V: 1.0 | | 3.0 |4.0 T: 0 … 120 … 127 128 … 255 256 … 300 … 383 384 … ~~~ then: ~~~inferno open Time in valueAtOrAdjacent p (toTime (seconds 380)) == Some 3.0 // value from current chunk valueAtOrAdjacent p (toTime (seconds 130)) == Some 1.0 // value from previous chunk valueAtOrAdjacent p (toTime (seconds 200)) == Some 3.0 // value from next chunk valueAtOrAdjacent p (toTime (seconds 1024)) == None ~~~ |
valuesBetween : forall 'a . {implicit resolution : resolution} ⇒ series of 'a → time → time → array of ('a, time) | Returns all values between two times, using the implicit resolution. If the resolution is set to 1, this returns all the events (actual values, not approximations) in the given time window. |
zip : forall 'a 'b . array of 'a → array of 'b → array of ('a, 'b) | Zip two arrays into a array of tuples/pairs. If one input array is shorter than the other, excess elements of the longer array are discarded. zip [1, 2] ['a', 'b'] == [(1,'a'),(2,'b')] |
(!!) : forall 'a . array of 'a → int → 'a | Array indexing: an infix operator to get the ith element of an array. Throws a RuntimeError if i is out of bounds. |
(!=) : forall 'a . 'a → 'a → bool{#false,#true} | The (not) equals function works on any value of the same type. Always returns #true for functions |
(!?) : forall 'a . array of 'a → int → option of 'a | Safe array indexing: an infix operator to get the ith element of an array. Returns None if i is out of bounds. |
(%) : int → int → int |
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(&&) : forall 'a . {requires bitlike on 'a} ⇒ 'a → 'a → 'a | Bitwise AND |
(*) : forall 'a 'b 'c . {requires multiplication on 'a 'b 'c} ⇒ 'a → 'b → 'c | Multiplication on int, double |
(**) : forall 'a . {requires power on 'a} ⇒ 'a → 'a → 'a | x ** y raises x to the power of y, where the arguments are int or double |
(+) : forall 'a 'b 'c . {requires addition on 'a 'b 'c} ⇒ 'a → 'b → 'c | Addition on int, double, word16/32/64, time and timeDiff |
(-) : forall 'a 'b 'c . {requires subtraction on 'a 'b 'c} ⇒ 'a → 'b → 'c | Subtraction on int, double, word16/32/64, time and timeDiff |
(..) : int → int → array of int |
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(/) : forall 'a 'b 'c . {requires division on 'a 'b 'c} ⇒ 'a → 'b → 'c | Division on int, double |
(<) : forall 'a . {requires order on 'a} ⇒ 'a → 'a → bool{#false,#true} | Ordering on int, double, word16/32/64, time and timeDiff |
(<<) : forall 'a 'b 'c . ('a → 'b) → ('c → 'a) → 'c → 'b | Function composition. (f << g) x == f (g x) |
(<=) : forall 'a . {requires order on 'a} ⇒ 'a → 'a → bool{#false,#true} | Ordering on int, double, word16/32/64, time and timeDiff |
(==) : forall 'a . 'a → 'a → bool{#false,#true} | The equality function works on any value of the same type. Always returns #false for functions |
(>) : forall 'a . {requires order on 'a} ⇒ 'a → 'a → bool{#false,#true} | Ordering on int, double, word16/32/64, time and timeDiff |
(>=) : forall 'a . {requires order on 'a} ⇒ 'a → 'a → bool{#false,#true} | Ordering on int, double, word16/32/64, time and timeDiff |
(?) : forall 'a . option of 'a → 'a → 'a | The ? function unwraps an optional value, if given a default value to fall back on in case the value of the optional is None. ~~~inferno (Some “hello”) ? “hi” == “hello” None ? “hi” == “hi” ~~~ |
(XOR) : forall 'a . {requires bitlike on 'a} ⇒ 'a → 'a → 'a | Bitwise XOR |
(|>) : forall 'a 'b . 'a → ('a → 'b) → 'b | The pipe operator. x |> f |> g == g (f x) |
(||) : forall 'a . {requires bitlike on 'a} ⇒ 'a → 'a → 'a | Bitwise OR |
Module Array
Item | Description |
argmax : forall 'a . {requires order on 'a} ⇒ array of 'a → option of int | The index of the maximum value in an array, or None if empty |
argmin : forall 'a . {requires order on 'a} ⇒ array of 'a → option of int | The index of the minimum value in an array, or None if empty |
argsort : forall 'a . {requires order on 'a} ⇒ array of 'a → array of int | Returns the indices that would sort an array |
average : forall 'a . {requires numeric on 'a} ⇒ array of 'a → option of double | The average of the values in an array, or None if empty |
findFirstAndLastSome : forall 'a . array of (option of 'a) → option of ('a, 'a) |
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findFirstSome : forall 'a . array of (option of 'a) → option of 'a |
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findLastSome : forall 'a . array of (option of 'a) → option of 'a |
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get : forall 'a . array of 'a → int → 'a | Array indexing: gets the ith element of an array. Throws a RuntimeError if i is out of bounds. |
getOpt : forall 'a . array of 'a → int → option of 'a | Safe array indexing: gets the ith element of an array. Returns None if i is out of bounds. |
keepSomes : forall 'a . array of (option of 'a) → array of 'a | Array.keepSomes discards any None values in an array and unwaps all Somes. ~~~inferno Array.keepSomes [None, Some “hello”, None, Some “world”] = [“hello”, “world”] ~~~ |
length : forall 'a . array of 'a → int
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magnitude : forall 'a . {requires numeric on 'a} ⇒ array of 'a → option of double | Returns the Euclidean norm of an array, or None if empty |
map : forall 'a 'b . ('a → 'b) → array of 'a → array of 'b | The Array.map function takes a function f and an array of elements and applies f to each one |
maximum : forall 'a . {requires order on 'a} ⇒ array of 'a → option of 'a | The maximum value in an array, or None if empty |
median : forall 'a . {requires numeric on 'a} ⇒ array of 'a → option of double | Return the median of the values in an array, or None if empty |
minimum : forall 'a . {requires order on 'a} ⇒ array of 'a → option of 'a | The minimum value in an array, or None if empty |
norm : forall 'a . {requires numeric on 'a} ⇒ array of 'a → option of double | Returns the Euclidean norm of an array, or None if empty |
range : int → int → array of int | The Array.range function takes two int arguments n and m and produces an array [n,...,m]. If m > n, the empty array is returned. |
reduce : forall 'a 'b . ('a → 'b → 'a) → 'a → array of 'b → 'a |
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reduceRight : forall 'a 'b . ('a → 'b → 'b) → 'b → array of 'a → 'b |
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singleton : forall 'a . 'a → array of ' | This function can be used to create an array with a single element: ~~~inferno singleton 2 ~~~ |
sum : forall 'a 'b . {requires addition on 'b 'a 'b ,requires rep on 'b ,requires zero on 'b} ⇒ array of 'a → 'b | Array.sum computes the sum of elements in an array. The elements can be of type int/double/word. |
zero : forall 'a . {requires rep on 'a,requires zero on 'a} ⇒ 'a |
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Module Option
| Item | Description |
join : forall 'a . option of (option of 'a) → option of 'a | Option.join removes the outer “layer” of a nesteed option. (By definition, Option.join == Option.reduce id None). ~~~inferno Option.join None == None Option.join (Some None) == None Option.join (Some (Some a)) == Some a ~~~ |
map : forall 'a 'b . ('a → 'b) → option of 'a → option of 'b | Option.map f ma applies f to the value inside ma, namely if ma is Some a, it will return Some (f a). |
mergeTuple : forall 'a 'b . (option of 'a, option of 'b) → option of ('a, 'b) | Given a tuple (Some x , Some y), Option.mergeTuple`` returnsSome (x , y)otherwise it returnsNone`. |
reduce : forall 'a 'b . ('a → 'b) → 'b → option of 'a → 'b | Option.reduce f o d unwraps an optional value o and applies f to it, if o contains a Some value. Otherwise it returns the default value d. ~~~inferno Option.reduce (fun str -> ${str} there!) “hi” (Some “hello”) == “hello there!” Option.reduce (fun str -> ${str} there!) “hi” None == “hi” ~~~ |
singleton : forall 'a . 'a → option of 'a |
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Module Text
append : text → text → text
length : text → int
splitAt : int → text → (text, text)
strip : text → text
Module Time
day : time → time
Rounds down to the start of the nearest day
days : int → timeDiff
daysBefore : time → int → time
formatTime : time → text → text
Format time to string
hour : time → time
Rounds down to the start of the nearest hour
hours : int → timeDiff
hoursBefore : time → int → time
intervalEvery : timeDiff → time → time → array of time
minutes : int → timeDiff
minutesBefore : time → int → time
month : time → time
Rounds down to the start of the nearest month
monthsBefore : time → int → time
Subtracts the given number of months, with days past the last day of the month clipped to the last day. For instance, 1 month before 2005-03-30 is 2005-02-28.
seconds : int → timeDiff
secondsBefore : time → int → time
timeToInt : time → int
Convert time to int (returned as seconds)
toTime : timeDiff → time
weeks : int → timeDiff
weeksBefore : time → int → time
year : time → time
Rounds down to the start of the nearest year
yearsBefore : time → int → time
Subtracts the given number of years, with days past the last day of the month clipped to the last day. For instance, 2 years before 2006-02-29 is 2004-02-28.
Type Classes
abs
- int
- double
- timeDiff
addition
- int int int
- int double double
- double int double
- double double double
- word16 word16 word16
- word16 word32 word32
- word16 word64 word64
- word32 word16 word32
- word32 word32 word32
- word32 word64 word64
- word64 word16 word64
- word64 word32 word64
- word64 word64 word64
- time timeDiff time
- timeDiff time time
- timeDiff timeDiff timeDiff
bitlike
- word16
- word32
- word64
- bool{#false,#true}
division
- int int int
- int double double
- double int double
- double double double
fromWord
- word16
- word32
- word64
- bool{#false,#true}
multiplication
- int int int
- int double double
- int timeDiff timeDiff
- double int double
- double double double
- timeDiff int timeDiff
negate
- int
- double
- timeDiff
order
- int
- double
- time
- timeDiff
power
- int
- double
roundable
- int
- double
subtraction
- int int int
- int double double
- double int double
- double double double
- word16 word16 word16
- word32 word32 word32
- word64 word64 word64
- time timeDiff time
- timeDiff timeDiff timeDiff
toWord16
- int
- word16
- word32
- word64
- bool{#false,#true}
toWord32
- int
- word16
- word32
- word64
- bool{#false,#true}
toWord64
- int
- word16
- word32
- word64
- bool{#false,#true}
zero
- int
- double
- word16
- word32
- word64
- timeDiff
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