Expression Operators

Operator	Description
Common Operators
count (count coll)	Returns the number of items in the collection. Using (count nil) returns 0. Using (count string), where string is replaced with your string data, returns the length of the string.
String Operators
regex (regex patterns s)	Checks if a string matches a pattern and returns a true response if it does and false if not. Any stray character is matched exactly. The Anyone character ('?') represents a single arbitrary character. Wildcards ('*') represent any number of arbitrary characters, including 0 Character classes are enclosed in square brackets and may contain an arbitrary list of characters to match. If a character class begins with a ('!') or ('^') character, the class will be negated meaning it will only match characters absent from the class. Empty character classes such as ('[]'), ('[!]'), and ('[^]') match their representation, not their content. Trees match any of their branches. Trees have their boundary limited defined in curly brackets with the content within separated by commas. Empty trees such as ('{}'), ('{,}'), and ('{,,}') match their representation, not their content.
str (str arg1 arg2 ....)	Links all arguments to a string. The example provided represents the argument fields by the arg values.
subs (subs s start) (subs s start end)	Returns the substring of the value used for s beginning at start (inclusive), and ending at end (exclusive). The end defaults to the length of the string.
join (join coll) (join separator coll)	Returns a string of all of the elements in a collection, as returned by (seq coll), separated by an operational separator.
escape (escape s cmap)	Returns a new string, using cmap to escape each character (ch) from s as follows: If (cmap ch) is nil, append ch to the new string If (cmap ch) is not nil, append (str (cmap ch)) instead
split (split s separator) (split s separator limit)	Splits a string into a list of strings with a separator.
split-lines (split-lines s)	Splits the value for s on \n or \r\n.
replace (replace s match replacement)	Replaces all instances of the value used for match with the value used for replacement in s. The match needs to be a string, not regex.
replace-first (replace-first s match replacement)	Replaces the first instance of the value used for match with the value used for replacement in s.
re-quote-replacement (re-quote-replacement replacement)	Given a replacement string that you wish to be a literal replacement for a pattern match in replace or replace-first, do the necessary escaping of special characters in the replacement.
reverse (reverse s)	Returns the value for s with it's characters reversed.
index-of (index-of s value) (index-of s value from-index)	Returns the index of the string or character value for s. Optionally, you search forwards from from-index point or nil if not found.
last-index-of (last index-of s value) (last-index-of s value from-index)	Returns the last index of the string or character value for s. Optionally, you can search backwards from from-index point or nil if not found.
capitalize (capitalize s)	Converts the first character of the string value to upper case and keeps all other characters lower case.
lower-case (lower-case s)	Converts the entire string to lower case characters.
upper-case (upper-case s)	Converts the entire string to upper case characters.
trim (trim s)	Removes any white space from both ends of the string.
trim-newline (trim-newline s)	Removes any trailing newline (\n) or return (\r) characters from the string.
triml (triml s)	Removes any white space from the left side of the string.
trimr (trimr s)	Removes any white space from the right side of the string.
render (render s)	Renders a mustache template with the current environment, using any assigned variables. If the variable is missing, the place holder will be resolved to an empty string as with the {{greeting}} variable below.
string? (string? x)	Returns as true if the value for x is a string.
blank? (blank? s)	Returns as true if the value for s is nil, empty, or contains only white space.
starts-with? (starts-with? s substr)	Returns as true if the string (s) starts with the substring (substr) provided.
end-with? (ends-with? s substr)	Returns as true if the string (s) ends with the substring (substr) provided.
includes? (includes? s substr)	Returns as true if the string (s) includes the substring (substr) provided.
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Arithmetic Operators
+ (+) (+ x) (+ x y) (+ x y & more)	Returns the sum of numbers. (+) returns 0
- (- x) (- x y) (- x y & more)	Subtracts the y's from x and returns the result. If no y's are supplied, returns the negation of x
* () ( x) (* x y) (* x y & more)	Returns the product of the numbers. (*) returns a value of 1
/ (/ x) (/ x y) (/ x y & more)	Returns the numerator divided by all of the denominators. If no denominators are supplied, returns 1/numerator
quot (quot num div)	Returns the quotient of dividing the numerator by the denominator. (quot m n) is the value of m/n, rounded towards 0 to the nearest integer. m, n do not need to be integers.
rem (rem num div)	Returns the remainder of dividing the numerator by the denominator. rem and mod are commonly used to get the remainder. mod means Gaussian mod, sot he result is always non-negative. Don't confuse it with ANCI C's % operator which, despite being pronounced "mod", actually implements rem as with (rem -10 3) -1.
mod (mod num div)	Returns the modulus of num and div. Truncates towards negative infinity. It's defined as the amount by which a number exceeds the largest integer multiple of the divisor that is not greater than that number. The largest integer multiple of 5 not greater than -2 is 5 * -1 = -5. The amount by which -2 exceeds -5 is 3.
inc (inc x)	Returns a number one greater than num.
dec (dec x)	Returns a number one less than the num.
max (max x) (max x y) (max x y & more)	Returns the greatest of the nums.
min (max x) (max x y) (max x y & more)	Returns the least of the nums.
+' (+') (+' x) (+' x y) (+' x y & more)	Returns the sum of the numbs. (+) returns 0. Supports arbitrary precision.
-' (-' x) (-' x y) (-' x y & more)	Subtracts the y's from x and returns the result. If no y's are supplied, returns the negation of x. Supports arbitrary precision.
' (') (' x) (' x y) (*' x y & more)	Returns the product of the numbers. (*) returns a value of 1. Supports arbitrary precision.
inc' (inc' x)	Returns a number one greater than num. Supports arbitrary precision.
dec' (dec' x)	Returns a number one less than the num. Supports arbitrary precision.
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Math Operators
rand (rand) (rand n)	Returns a random floating point number between 0 (inclusive) and n (default 1) (exclusive).
rand-int (rand-int n)	Returns a random integer between 0 (inclusive) and n (exclusive).
abs (abs x)	Returns the absolute value of x.
floor (floor x)	Returns x, rounded down to the nearest integer.
ceiling (ceiling x)	Returns x, rounded up to the nearest integer.
round (round x y)	If the fractional portion of x is 0.5 or greater, the argument is rounded up to the nearest integer. If the fractional portion of x is less than 0.5, the argument is rounded down to the nearest integer. If y is specified then it will round x to the number of decimal places specified. If y=0 then it will round to the nearest integer.
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Number Comparison Operators
zero? (zero? x)	Returns true if num is zero, otherwise it's false.
pos? (pos? x)	Returns true if num is greater than zero, otherwise it's false.
neg? (nex? x)	Returns true if num is less than zero, otherwise it's false.
even? (even? n)	Returns true if n is even, otherwise it's false. Throws an exception if n is not an integer.
odd? (odd? n)	Returns true if n is odd, otherwise it's false. Throws an exception if n is not an integer.
number? (number? x)	Returns true if x is a number.
rational? (rational? n)	Returns true if n is a rational number, otherwise it's false.
integer? (integer? n)	Returns true if n is an integer, otherwise it's false.
ratio? (ratio? n)	Returns true if n as a ratio, otherwise it's false.
decimal? (decimal? n)	Returns true if n is a BigDecimal, otherwise it's false.
float? (float? n)	Returns true if n is a floating point number, otherwise it's false.
sort (sort coll) (sort comp coll)	Returns a sorted sequence of the items in the collection (coll). It checks to see if a string matches on a pattern and returns true/false.
sort-by (sort-by key coll) (sort-by key comp coll)	Returns a sorted sequence of the items in the collection (coll), where the sort order is determined by comparing the key value of each item.
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UUIDs
as-uuid	The as-uuid function will allow the conversion (and also verification) of a string to a uuid object. If the passed object is already a uuid, the same object will be returned.
uuid-v1	The uuid-v1 function will return a new v1 UUID. The value returned will be a UUID, not a string.
uuidable? (uuidable? x)	Returns true if x can be coerced into a uuid, otherwise it's false.
uuid? (uuid? x)	Returns true if x is a uuid, otherwise it's false.
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Phone Number Operators
phone-number (phone-number number) (phone-number number locale)	Parses a string telephone number into a map of different formats. Adding the locale parses a string number, using locale, into a map of different formats.
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Date and Time Operators
days-this-month (days-this-month)	Returns the number of days in the current month.
days-in-month (days-in-month date)	Returns the number of days in the month of a specified date.
now (now)	Returns the current date and time.
today (today)	Returns today's date. Does not include the time.
today-at-midnight (today-at-midnight)	Returns the date and time as of midnight today.
yesterday (yesterday)	Returns the date for yesterday. Does not include a time.
tomorrow (tomorrow)	Returns the date for tomorrow. Does not include a time.
ago (ago t)	Returns the date and time as it was t seconds/minutes/hours/days/months/years ago.
from-now (from-now t)	Returns the date and time that it will be in t seconds/minutes/hours/days/months/years from now.
second (second t)	Returns the seconds portion of a date specified by t.
minute (minute t)	Returns the minutes portion of a date specified by t.
hour (hour t)	Returns the hour portion of a date specified by t.
day (day t)	Returns the day of the month in a date specified by t.
month (month t)	Returns the month portion of a date, specified by t, as number. For example, March would return as 3.
quarter (quarter t start)	Returns the quarter of a date along with the year. The start is the number of the month in the year that you want the quarters to start in. If no start is specified, then January (1) is used as the start of the quarters. For example, if the start = 1 or isn't specified, returns the year along with: 1 if the month is January, February, or March 2 if the month is April, May, or June 3 if the month is July, August, or September 4 if the month is October, November, or December. Alternatively, if the start = 5, returns the year along with: 1 if the month is May, June, or July 2 if the month is August, September, or October 3 if the month is November, December, or January 4 if the month is February, March, or April
year (year t)	Returns the year portion of a date specified by t.
day-of-week (day-of-week t)	Returns the numeric value for the day of the week for a given date (t), between 1 and 7, where Sunday is considered 1 and the first day of the week.
week-of-year (week-of-year t)	Returns the number value for the week of the year for a given date (t).
end-of-month (end-of-month t)	Returns the numeric value for the last day of the month (t).
beginning-of-month (beginning-of-month t)	Returns the numeric value for the beginning of the month (t).
at-midnight (at-midnight t)	Returns the date/time at midnight for a given date (t).
ampm (ampm t)	Returns am if the current time is between 00:00 inclusive and 12:00 exclusive. Returns pm if the current time is between 12:00 inclusive and 00:00 exclusive. 11:59:59 would return am, while 23:59:59 would return pm.
timezone-offset (timezone-offset d) (timezone-ofset d d2)	Returns the offset between a date (d) and another (d2). If no other date (d2) is provided, uses UTC date.
interval (interval date1 date2)	Returns the interval between date1 and date2. date1 must be earlier than or the same time as date2
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Date and Time Periods
seconds (seconds t)	Returns a date considered to be that many seconds.
minutes (mintues t)	Returns a date considered to be that many minutes.
hours (hours t)	Returns a date considered to be that many hours.
days (days t)	Returns a date considred to be that many days.
months (months t)	Returns a date considered to be that many months.
quarters (quarters t)	Returns a date considered to be that many quarters. A quarter is considered to be a 3 month period of a year.
years (years t)	Returns a date considered to be that many years.
in-seconds (in-seconds p)	Returns the number of seconds in a given period. See in-years for an example.
in-days (in-days p)	Returns the number of days in a given period. See in-years for an example.
in-weeks (in-weeks p)	Returns the number of weeks in a given period. See in-years for an example.
in-months (in-months p)	Returns the number of months in a given period. See in-years for an example.
in-years (in-years p)	Returns the number of years in a given period.
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Date and Time Predicates and Comparators
after? (afetr? a b)	Returns true if a comes after b, otherwise it is false. For example, (after? (tomorrow) (now)) will return true.
before? (before? a c)	Returns true if a occurs after b, otherwise it is false. For example, (before? (yesterday) (now)) will return true.
within? (within? a b c)	Returns true if b occurs after a and before c, otherwise it is false. For example, (within? (yesterday) (tomorrow) (now)) will return true.
earliest (earliest a b c & more)	Returns the earliest date/time in a given list of date/times. For example, (earliest (yesterday) (now)) will return the date for yesterday.
latest (latest a b c & more)	Returns the latest date/time in a given list of date/times. For example, (latest (yesterday) (now)) will return the date for now.
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Date and Time Conversion
unix-timestamp (unix-timestamp s)	Converts s to an unix timestamp. s could be a datetime string or datetime object.
timestamp (timestamp s)	Converts s to a datetime object. s could be a datetime string or datetime object.
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Date and Time Formatting
format-date (format-date t) (format-date formatter t)	Given a date, returns the date in a specified format. Click here for a list of built in formatters. Click on the thumbnail to expan the image, or see the text versions below: :basic-date 20160520 :basic-date-time 20160520T035923.662Z :basic-date-time-no-ms 20160520T035923Z :basic-ordinal-date 2016141 :basic-ordinal-date-time 2016141T035923.662Z :basic-ordinal-date-time-no-ms 2016141T035923Z :basic-t-time T035923.662Z :basic-t-time-no-ms T035923Z :basic-time 035923.662Z :basic-time-no-ms 035923Z :basic-week-date 2016W205 :basic-week-date-time 2016W205T035923.662Z :basic-week-date-time-no-ms 2016W205T035923Z :date 2016-05-20 :date-hour 2016-05-20T03 :date-hour-minute 2016-05-20T03:59 :date-hour-minute-second 2016-05-20T03:59:23 :date-hour-minute-second-fraction 2016-05-20T03:59:23.662 :date-hour-minute-second-ms 2016-05-20T03:59:23.662 :date-time 2016-05-20T03:59:23.662Z :date-time-no-ms 2016-05-20T03:59:23Z :hour 03 :hour-minute 03:59 :hour-minute-second 03:59:23 :hour-minute-second-fraction 03:59:23.662 :hour-minute-second-ms 03:59:23.662 :mysql 2016-05-20 03:59:23 :ordinal-date 2016-141 :ordinal-date-time 2016-141T03:59:23.662Z :ordinal-date-time-no-ms 2016-141T03:59:23Z :rfc822 Fri, 20 May 2016 03:59:23 +0000 :t-time T03:59:23.662Z :t-time-no-ms T03:59:23Z :time 03:59:23.662Z :time-no-ms 03:59:23Z :week-date 2016-W20-5 :week-date-time 2016-W20-5T03:59:23.662Z :week-date-time-no-ms 2016-W20-5T03:59:23Z :weekyear 2016 :weekyear-week 2016-W20 :weekyear-week-day 2016-W20-5 :year 2016 :year-month 2016-05 :year-month-day 2016-05-20
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Maps
get (get <map> <key>)	Allows for the retrieval of a key from a map. The key will always be cast to a keyword. You can also use the dot syntax instead of the get command.
get-in (get <map> [<key>*])	Allows for deep access to a map. As with get, you can also use dot notation.
assoc (get <map> <<key> <value>>*)	Allows you to add a key and a value to a map. If the key already exists in the map, the original value will be overwritten.
assoc-in (assoc <map> <<key> <value>*)	Allows you to add a key and a value to a map. If the key already exists in the map, the original value will be overwritten.
select-keys (select-keys <map> <key>*)	Returns a map which only contains the keys specified. If any of the keys do not exist in the provided map, they will not be present in the resulting map.
remove-keys (remove-keys <map> <key>*)	Removes the provided keys from the provided map. Keys will automatically be converted to keywords.
filter-vals (filter-vals <map> <predicate>)	Specifies a predicate to test all the values of a map with. All values which result in true will be kept, and all false values will be discarded along with their keys. When specifying the predicate fn in the placeholder for the value is the _ symbol. While the predicate fn can be arbitrarily complex, the _ charachter must appear at the top level.
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Lists
add (add <list> <value>*)	Adds a value to the end of a list.
remove (remove <list> <value>*)	Removes all occurrences of a value from a list.
contains? (contains <list> <value>)	Returns true if a list contains the value specified, otherwise it is false.
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Control
if (if <predicate> <true> [<false>])	The if command is the basic control structure, allowing for true and false (else) paths. If no false path is provided, it will evaluate to nil.
cond (cond <<predicate> <value>>* [:else <value>])	The cond command is an extension of if and allows for a more compact expression of multiple predicates. Optionally, an else value can be provided by adding the predicate :else at the last predicate/value pair.
find (find <list> <lookup-key> <value>)	Allows for searching a list of maps for the first element that equals the provided value. In it's current form, find is only useful for a list of maps.
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Comparator Operators
=	Returns true if x equals y, false if not.
!=	Negation of =.
not	Returns true if x is logical false, false if not.
not=	Negation of =.
>	Returns non-nil if numbers are in monotonically decreasing order, otherwise it's false.
>=	Returns non-nil if numbers are in monotonically non-increasing order, otherwise it's false.
<	Returns non-nil if numbers are in monotonically increasing orde, otherwise it's false.
<=	Returns non-nil if numbers are in monotonically non-decreasing order, otherwise it's false.
and	Evaluates expression one at a time, from left to right. If a form returns logical false (nil or false), and returns that value and doesn't evaluate any of the other expressions, otherwise it returns the value of the last expression. (and) returns true.
or	Evaluates expression one at a time, from left to right. If a form returns a logical true value, or returns that value and doesn't evaluate any of the other expressions, otherwise it returns the value of the last expression. (or) returns nil.
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Common Operators

count

(count coll)

Returns the number of items in the collection.

Using (count nil) returns 0.
Using (count string), where string is replaced with your string data, returns the length of the string.

Screen image of the count expression in use

String Operators

regex

(regex patterns s)

Checks if a string matches a pattern and returns a true response if it does and false if not.

Any stray character is matched exactly.
The Anyone character ('?') represents a single arbitrary character.
Wildcards ('*') represent any number of arbitrary characters, including 0
Character classes are enclosed in square brackets and may contain an arbitrary list of characters to match. If a character class begins with a ('!') or ('^') character, the class will be negated meaning it will only match characters absent from the class. Empty character classes such as ('[]'), ('[!]'), and ('[^]') match their representation, not their content.
Trees match any of their branches. Trees have their boundary limited defined in curly brackets with the content within separated by commas. Empty trees such as ('{}'), ('{,}'), and ('{,,}') match their representation, not their content.

Screen image of the regex operator in use

str

(str arg1 arg2 ....)

Links all arguments to a string. The example provided represents the argument fields by the arg values.

Screen image of the str expression in use

subs

(subs s start)

(subs s start end)

Returns the substring of the value used for s beginning at start (inclusive), and ending at end (exclusive). The end defaults to the length of the string.

Screen image of the subs operator in use

join

(join coll)

(join separator coll)

Returns a string of all of the elements in a collection, as returned by (seq coll), separated by an operational separator.

Screen image of the join operator in use

escape

(escape s cmap)

Returns a new string, using cmap to escape each character (ch) from s as follows:

If (cmap ch) is nil, append ch to the new string
If (cmap ch) is not nil, append (str (cmap ch)) instead

Screen image of the escape operator in use

split

(split s separator)

(split s separator limit)

Splits a string into a list of strings with a separator.

Image of the split expression in use.

split-lines

(split-lines s)

Splits the value for s on \n or \r\n.

Screen image of the split-lines expression in use

replace

(replace s match replacement)

Replaces all instances of the value used for match with the value used for replacement in s.

The match needs to be a string, not regex.

Screen image of the replace expression in use

replace-first

(replace-first s match replacement)

Replaces the first instance of the value used for match with the value used for replacement in s.

Screen image of the replace-first expression in use

re-quote-replacement

(re-quote-replacement replacement)

Given a replacement string that you wish to be a literal replacement for a pattern match in replace or replace-first, do the necessary escaping of special characters in the replacement.

reverse

(reverse s)

Returns the value for s with it's characters reversed.

Screen image of the reverse expression in use

index-of

(index-of s value)

(index-of s value from-index)

Returns the index of the string or character value for s.

Optionally, you search forwards from from-index point or nil if not found.

Screen image of the index-of expression in use

last-index-of

(last index-of s value)

(last-index-of s value from-index)

Returns the last index of the string or character value for s.

Optionally, you can search backwards from from-index point or nil if not found.

Screen image of the last-index-of expression in use

capitalize

(capitalize s)

Converts the first character of the string value to upper case and keeps all other characters lower case.

Screen image of the capitalize expression in use

lower-case

(lower-case s)

Converts the entire string to lower case characters.

Screen image of the lower-case expression in use

upper-case

(upper-case s)

Converts the entire string to upper case characters.

Screen image of the upper-case expression in use

trim

(trim s)

Removes any white space from both ends of the string.

Screen image of the trim expression in use

trim-newline

(trim-newline s)

Removes any trailing newline (\n) or return (\r) characters from the string.

Screen image of the trim-newline expression in use

triml

(triml s)

Removes any white space from the left side of the string.

Screen image of the triml expression in use

trimr

(trimr s)

Removes any white space from the right side of the string.

Screen image of the trimr expression in use

render

(render s)

Renders a mustache template with the current environment, using any assigned variables. If the variable is missing, the place holder will be resolved to an empty string as with the {{greeting}} variable below.

Screen image of the render expression in use

string?

(string? x)

Returns as true if the value for x is a string.

Screen image of the string? expression in use

blank?

(blank? s)

Returns as true if the value for s is nil, empty, or contains only white space.

starts-with?

(starts-with? s substr)

Returns as true if the string (s) starts with the substring (substr) provided.

Screen image of the starts-with? expression in use

end-with?

(ends-with? s substr)

Returns as true if the string (s) ends with the substring (substr) provided.

Screen image of the ends-with? expression in use

includes?

(includes? s substr)

Returns as true if the string (s) includes the substring (substr) provided.

Screen image of the includes? expression in use

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Arithmetic Operators

+

(+)

(+ x)

(+ x y)

(+ x y & more)

Returns the sum of numbers.

(+) returns 0

Screen image of the + expression in use.

-

(- x)

(- x y)

(- x y & more)

Subtracts the y's from x and returns the result.

If no y's are supplied, returns the negation of x

Screen image of the - expression in use

*

(*)

(* x)

(* x y)

(* x y & more)

Returns the product of the numbers.

(*) returns a value of 1

Screen image of the * expression in use

/

(/ x)

(/ x y)

(/ x y & more)

Returns the numerator divided by all of the denominators.

If no denominators are supplied, returns 1/numerator

Screen image of the / expression in use

quot

(quot num div)

Returns the quotient of dividing the numerator by the denominator.

(quot m n) is the value of m/n, rounded towards 0 to the nearest integer.
m, n do not need to be integers.

Screen image of the quot expression in use

rem

(rem num div)

Returns the remainder of dividing the numerator by the denominator.

rem and mod are commonly used to get the remainder. mod means Gaussian mod, sot he result is always non-negative. Don't confuse it with ANCI C's % operator which, despite being pronounced "mod", actually implements rem as with (rem -10 3) -1.

Screen image of the rem expression in use

mod

(mod num div)

Returns the modulus of num and div.

Truncates towards negative infinity.
It's defined as the amount by which a number exceeds the largest integer multiple of the divisor that is not greater than that number. The largest integer multiple of 5 not greater than -2 is 5 * -1 = -5. The amount by which -2 exceeds -5 is 3.

Screen image of the mod expression in use

inc

(inc x)

Returns a number one greater than num.

Screen image of the inc expression in use

dec

(dec x)

Returns a number one less than the num.

Screen image of the dec expression in use

max

(max x)

(max x y)

(max x y & more)

Returns the greatest of the nums.

Screen image of the max expression in use

min

(max x)

(max x y)

(max x y & more)

Returns the least of the nums.

Screen image of the min expression in use

+'

(+')

(+' x)

(+' x y)

(+' x y & more)

Returns the sum of the numbs.

(+) returns 0.
Supports arbitrary precision.

-'

(-' x)

(-' x y)

(-' x y & more)

Subtracts the y's from x and returns the result.

If no y's are supplied, returns the negation of x.
Supports arbitrary precision.

*'

(*')

(*' x)

(*' x y)

(*' x y & more)

Returns the product of the numbers.

(*) returns a value of 1.
Supports arbitrary precision.

inc'

(inc' x)

Returns a number one greater than num.

Supports arbitrary precision.

dec'

(dec' x)

Returns a number one less than the num.

Supports arbitrary precision.

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Math Operators

rand

(rand)

(rand n)

Returns a random floating point number between 0 (inclusive) and n (default 1) (exclusive).

Screen image of the rand expression in use

rand-int

(rand-int n)

Returns a random integer between 0 (inclusive) and n (exclusive).

Screen image of the rand-int expression in use

abs

(abs x)

Returns the absolute value of x.

Screen image of the abs expression in use

floor

(floor x)

Returns x, rounded down to the nearest integer.

Screen image of the floor expression in use

ceiling

(ceiling x)

Returns x, rounded up to the nearest integer.

Screen image of the ceiling expression in use

round

(round x y)

If the fractional portion of x is 0.5 or greater, the argument is rounded up to the nearest integer. If the fractional portion of x is less than 0.5, the argument is rounded down to the nearest integer.

If y is specified then it will round x to the number of decimal places specified.
If y=0 then it will round to the nearest integer.

Screen image of the round expression in use

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Number Comparison Operators

zero?

(zero? x)

Returns true if num is zero, otherwise it's false.

Screen image of the zero? expression in use

pos?

(pos? x)

Returns true if num is greater than zero, otherwise it's false.

Screen image of the pos expression in use

neg?

(nex? x)

Returns true if num is less than zero, otherwise it's false.

Screen image of the neg? expression in use

even?

(even? n)

Returns true if n is even, otherwise it's false.

Throws an exception if n is not an integer.

Screen image of the even? expression in use

odd?

(odd? n)

Returns true if n is odd, otherwise it's false.

Throws an exception if n is not an integer.

Screen image of the odd? expression in use

number?

(number? x)

Returns true if x is a number.

Screen image of the number? expression in use

rational?

(rational? n)

Returns true if n is a rational number, otherwise it's false.

integer?

(integer? n)

Returns true if n is an integer, otherwise it's false.

Screen image of the integer expression in use

ratio?

(ratio? n)

Returns true if n as a ratio, otherwise it's false.

decimal?

(decimal? n)

Returns true if n is a BigDecimal, otherwise it's false.

float?

(float? n)

Returns true if n is a floating point number, otherwise it's false.

sort

(sort coll)

(sort comp coll)

Returns a sorted sequence of the items in the collection (coll). It checks to see if a string matches on a pattern and returns true/false.

sort-by

(sort-by key coll)

(sort-by key comp coll)

Returns a sorted sequence of the items in the collection (coll), where the sort order is determined by comparing the key value of each item.

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UUIDs

as-uuid

The as-uuid function will allow the conversion (and also verification) of a string to a uuid object. If the passed object is already a uuid, the same object will be returned.

Screen image of the as-uuid expression in use.

uuid-v1

The uuid-v1 function will return a new v1 UUID. The value returned will be a UUID, not a string.

Screen image of the uuid-v1 expression in use.

uuidable?

(uuidable? x)

Returns true if x can be coerced into a uuid, otherwise it's false.

Screen image of the uuidable? expression in use.

uuid?

(uuid? x)

Returns true if x is a uuid, otherwise it's false.

Screen image of the uuid? expression in use.

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Phone Number Operators

phone-number

(phone-number number)

(phone-number number locale)

Parses a string telephone number into a map of different formats.

Adding the locale parses a string number, using locale, into a map of different formats.

Screen image of the phone-number expression in use.

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Date and Time Operators

days-this-month

(days-this-month)

Returns the number of days in the current month.

Screen image of the days-this-month expression in use.

days-in-month

(days-in-month date)

Returns the number of days in the month of a specified date.

Screen image of the days-in-month expression in use.

now

(now)

Returns the current date and time.

today

(today)

Returns today's date.

Does not include the time.

today-at-midnight

(today-at-midnight)

Returns the date and time as of midnight today.

yesterday

(yesterday)

Returns the date for yesterday.

Does not include a time.

tomorrow

(tomorrow)

Returns the date for tomorrow.

Does not include a time.

ago

(ago t)

Returns the date and time as it was t seconds/minutes/hours/days/months/years ago.

from-now

(from-now t)

Returns the date and time that it will be in t seconds/minutes/hours/days/months/years from now.

second

(second t)

Returns the seconds portion of a date specified by t.

minute

(minute t)

Returns the minutes portion of a date specified by t.

hour

(hour t)

Returns the hour portion of a date specified by t.

day

(day t)

Returns the day of the month in a date specified by t.

month

(month t)

Returns the month portion of a date, specified by t, as number.

For example, March would return as 3.

quarter

(quarter t start)

Returns the quarter of a date along with the year. The start is the number of the month in the year that you want the quarters to start in. If no start is specified, then January (1) is used as the start of the quarters.

For example, if the start = 1 or isn't specified, returns the year along with:

1 if the month is January, February, or March
2 if the month is April, May, or June
3 if the month is July, August, or September
4 if the month is October, November, or December.

Alternatively, if the start = 5, returns the year along with:

1 if the month is May, June, or July
2 if the month is August, September, or October
3 if the month is November, December, or January
4 if the month is February, March, or April

Screen image of the quarter expression in use.

year

(year t)

Returns the year portion of a date specified by t.

day-of-week

(day-of-week t)

Returns the numeric value for the day of the week for a given date (t), between 1 and 7, where Sunday is considered 1 and the first day of the week.

week-of-year

(week-of-year t)

Returns the number value for the week of the year for a given date (t).

end-of-month

(end-of-month t)

Returns the numeric value for the last day of the month (t).

beginning-of-month

(beginning-of-month t)

Returns the numeric value for the beginning of the month (t).

at-midnight

(at-midnight t)

Returns the date/time at midnight for a given date (t).

ampm

(ampm t)

Returns am if the current time is between 00:00 inclusive and 12:00 exclusive. Returns pm if the current time is between 12:00 inclusive and 00:00 exclusive.

11:59:59 would return am, while 23:59:59 would return pm.

Screen image of the ampm expression in use.

timezone-offset

(timezone-offset d)

(timezone-ofset d d2)

Returns the offset between a date (d) and another (d2).

If no other date (d2) is provided, uses UTC date.

Screen image of the timezone-offset expression in use.

interval

(interval date1 date2)

Returns the interval between date1 and date2.

date1 must be earlier than or the same time as date2

Screen image of the interval expression in use.

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Date and Time Periods

seconds

(seconds t)

Returns a date considered to be that many seconds.

minutes

(mintues t)

Returns a date considered to be that many minutes.

hours

(hours t)

Returns a date considered to be that many hours.

days

(days t)

Returns a date considred to be that many days.

months

(months t)

Returns a date considered to be that many months.

quarters

(quarters t)

Returns a date considered to be that many quarters.

A quarter is considered to be a 3 month period of a year.

years

(years t)

Returns a date considered to be that many years.

in-seconds

(in-seconds p)

Returns the number of seconds in a given period.

See in-years for an example.

in-days

(in-days p)

Returns the number of days in a given period.

See in-years for an example.

in-weeks

(in-weeks p)

Returns the number of weeks in a given period.

See in-years for an example.

in-months

(in-months p)

Returns the number of months in a given period.

See in-years for an example.

in-years

(in-years p)

Returns the number of years in a given period.

Screen image of the in-seconds and in-months expressions in use.

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Date and Time Predicates and Comparators

after?

(afetr? a b)

Returns true if a comes after b, otherwise it is false.

For example, (after? (tomorrow) (now)) will return true.

before?

(before? a c)

Returns true if a occurs after b, otherwise it is false.

For example, (before? (yesterday) (now)) will return true.

within?

(within? a b c)

Returns true if b occurs after a and before c, otherwise it is false.

For example, (within? (yesterday) (tomorrow) (now)) will return true.

earliest

(earliest a b c & more)

Returns the earliest date/time in a given list of date/times.

For example, (earliest (yesterday) (now)) will return the date for yesterday.

latest

(latest a b c & more)

Returns the latest date/time in a given list of date/times.

For example, (latest (yesterday) (now)) will return the date for now.

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Date and Time Conversion

unix-timestamp

(unix-timestamp s)

Converts s to an unix timestamp.

s could be a datetime string or datetime object.

Screen image of the unix-timestamp expression in use.

timestamp

(timestamp s)

Converts s to a datetime object.

s could be a datetime string or datetime object.

Screen image of the timestamp expression in use.

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Date and Time Formatting

format-date

(format-date t)

(format-date formatter t)

Given a date, returns the date in a specified format.

Screen image of the format-date expression in use.

Click here for a list of built in formatters.

Click on the thumbnail to expan the image, or see the text versions below: 
:basic-date                             20160520
:basic-date-time                        20160520T035923.662Z
:basic-date-time-no-ms                  20160520T035923Z
:basic-ordinal-date                     2016141
:basic-ordinal-date-time                2016141T035923.662Z
:basic-ordinal-date-time-no-ms          2016141T035923Z
:basic-t-time                           T035923.662Z
:basic-t-time-no-ms                     T035923Z
:basic-time                             035923.662Z
:basic-time-no-ms                       035923Z
:basic-week-date                        2016W205
:basic-week-date-time                   2016W205T035923.662Z
:basic-week-date-time-no-ms             2016W205T035923Z
:date                                   2016-05-20
:date-hour                              2016-05-20T03
:date-hour-minute                       2016-05-20T03:59
:date-hour-minute-second                2016-05-20T03:59:23
:date-hour-minute-second-fraction       2016-05-20T03:59:23.662
:date-hour-minute-second-ms             2016-05-20T03:59:23.662
:date-time                              2016-05-20T03:59:23.662Z
:date-time-no-ms                        2016-05-20T03:59:23Z
:hour                                   03
:hour-minute                            03:59
:hour-minute-second                     03:59:23
:hour-minute-second-fraction            03:59:23.662
:hour-minute-second-ms                  03:59:23.662
:mysql                                  2016-05-20 03:59:23
:ordinal-date                           2016-141
:ordinal-date-time                      2016-141T03:59:23.662Z
:ordinal-date-time-no-ms                2016-141T03:59:23Z
:rfc822                                 Fri, 20 May 2016 03:59:23 +0000
:t-time                                 T03:59:23.662Z
:t-time-no-ms                           T03:59:23Z
:time                                   03:59:23.662Z
:time-no-ms                             03:59:23Z
:week-date                              2016-W20-5
:week-date-time                         2016-W20-5T03:59:23.662Z
:week-date-time-no-ms                   2016-W20-5T03:59:23Z
:weekyear                               2016
:weekyear-week                          2016-W20
:weekyear-week-day                      2016-W20-5
:year                                   2016
:year-month                             2016-05
:year-month-day                         2016-05-20

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Maps

get

(get <map> <key>)

Allows for the retrieval of a key from a map.

The key will always be cast to a keyword.
You can also use the dot syntax instead of the get command.

Screen image of the get expression in use.

get-in

(get <map> [<key>*])

Allows for deep access to a map.

As with get, you can also use dot notation.

Screen image of the get-in expression in use.

assoc

(get <map> <<key> <value>>*)

Allows you to add a key and a value to a map.

If the key already exists in the map, the original value will be overwritten.

Screen image of the assoc expression in use.

assoc-in

(assoc <map> <<key> <value>*)

Allows you to add a key and a value to a map.

If the key already exists in the map, the original value will be overwritten.

Screen image of the assoc-in expression in use.

select-keys

(select-keys <map> <key>*)

Returns a map which only contains the keys specified.

If any of the keys do not exist in the provided map, they will not be present in the resulting map.

Screen image of the select-keys expression in use.

remove-keys

(remove-keys <map> <key>*)

Removes the provided keys from the provided map.

Keys will automatically be converted to keywords.

filter-vals

(filter-vals <map> <predicate>)

Specifies a predicate to test all the values of a map with.

All values which result in true will be kept, and all false values will be discarded along with their keys.
When specifying the predicate fn in the placeholder for the value is the _ symbol. While the predicate fn can be arbitrarily complex, the _ charachter must appear at the top level.

Screen image of the filter-vals expression in use.

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Lists

add

(add <list> <value>*)

Adds a value to the end of a list.

Screen image of the add expression in use.

remove

(remove <list> <value>*)

Removes all occurrences of a value from a list.

Screen image of the remove expression in use.

contains?

(contains <list> <value>)

Returns true if a list contains the value specified, otherwise it is false.

Screen image of the contains? expression in use.

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Control

if

(if <predicate> <true> [<false>])

The if command is the basic control structure, allowing for true and false (else) paths.

If no false path is provided, it will evaluate to nil.

Screen image of the if expression in use.

cond

(cond <<predicate> <value>>* [:else <value>])

The cond command is an extension of if and allows for a more compact expression of multiple predicates.

Optionally, an else value can be provided by adding the predicate :else at the last predicate/value pair.

Screen image of the cond expression in use.

find

(find <list> <lookup-key> <value>)

Allows for searching a list of maps for the first element that equals the provided value.

In it's current form, find is only useful for a list of maps.

Screen image of the find expression in use.

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Comparator Operators

=

Returns true if x equals y, false if not.

!=

Negation of =.

not

Returns true if x is logical false, false if not.

not=

Negation of =.

>

Returns non-nil if numbers are in monotonically decreasing order, otherwise it's false.

>=

Returns non-nil if numbers are in monotonically non-increasing order, otherwise it's false.

<

Returns non-nil if numbers are in monotonically increasing orde, otherwise it's false.

<=

Returns non-nil if numbers are in monotonically non-decreasing order, otherwise it's false.

and

Evaluates expression one at a time, from left to right.

If a form returns logical false (nil or false), and returns that value and doesn't evaluate any of the other expressions, otherwise it returns the value of the last expression.
(and) returns true.

or

Evaluates expression one at a time, from left to right.

If a form returns a logical true value, or returns that value and doesn't evaluate any of the other expressions, otherwise it returns the value of the last expression.
(or) returns nil.

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Flow Expression Operators