Filter Operators: 티들리위키 — 줄 없는 개인 웹 공책

Filter Operators

2023년 4월 10일 오전 11:41

A filter operator is a predefined keyword attached to an individual step of a filter. It defines the particular action of that step.

Important: In general, each first filter step of a filter run not given any input titles receives the output of [all[tiddlers]] as its input.

Table legend:

✓	...	Used to mark the most common ones
`!`	...	The column indicates whether an operator allows negation using the `!` prefix. For specifics as to each operator's negated output please refer to its documentation
`C`	...	Most steps process the selection of titles that are supplied as their input, but a few construct an entirely new selection instead, as indicated by the last column. A `C?` indicates it might construct a new selection, depending on usage. For specifics as to each operator's selection creation please refer to its documentation

The following table lists all core operators:

Operator	Purpose	✓	`!`	`C`
all	find all titles of a fundamental category	✓		`C?`
backlinks	find the titles that link to each input title
backtranscludes	find the titles that transclude each input title
charcode	generates string characters from their numeric character codes
contains	filter the input by searching list fields for a value		`!`
count	count the number of entries in a list
days	filter the input by date		`!`
duplicateslugs	find titles that yield duplicate slugs
each	select one of each group of input titles by field
eachday	select one of each group of input titles by date
else	if the list of input titles is empty then return a list consisting of a single constant string, otherwise return the original titles
enlist	select titles from the parameter interpreted as a title list		`!`	`C`
field	filter the input by field	✓	`!`
fields	select all field names of the input titles
filter	apply a subfilter to each input title and return the titles that return a non-empty result from the subfilter		`!`
function	apply a function to the input list, and return the result
get	select all values of a field in the input titles
getindex	select all values of a data property in the input titles
has	filter the input by field existence	✓	`!`
haschanged	filter the input by tiddler modification status		`!`
indexes	select all data properties of the input titles
is	filter the input by fundamental category	✓	`!`
join	join a list of strings together with the separator `S`
jsonextract	retrieve the JSON string of a property from JSON strings
jsonget	retrieve the value of a property from JSON strings
jsonindexes	retrieve the value of a property from JSON strings
jsonset	set the value of a property in JSON objects
jsontype	retrieve the type of a property from JSON strings
length	returns the number of characters of each item in the list
links	find the titles linked to by each input title	✓
list	select titles via a list field		`!`	`C`
listed	find the titles that list the input titles
lookup	applies a prefix to each input title to yield the title of a tiddler from which the final value is retrieved. With a single parameter, the default field is "text" and the default index is "0". If a second parameter is provided, that becomes the target field or index.
lowercase	returns each item in the list as lowercase
match	returns each item in the list that matches the parameter string
minlength	filter items whose length is greater than or equal to the specified minimum length
range	generate a range of numbers		`!`	`C`
reduce	apply a subfilter to each input title in turn, accumulating a single value
regexp	filter the input by pattern-matched field		`!`
sameday	filter the input by date
search	filter the input by searching tiddler content	✓	`!`
sentencecase	returns each item in the list with the first letter capitalised
slugify	returns each item in the list in a human-readable form for use in URLs or filenames
split	returns each item in the list split into separate strings according to the specified separator `S`; duplicates are not removed
splitregexp	returns each item in the list split into separate strings according to the specified regular expression `R`

subfilter	select titles from the parameter interpreted as a filter expression		`!`	`C?`

then	replace input titles by a constant string
title	select a single title	✓	`!`	`C`
titlecase	returns each item in the list with each word capitalised
transcludes	find the titles transcluded by each input title	✓
uppercase	returns each item in the list as uppercase
Order Operators
after	find which input title follows a specified one
before	find which input title precedes a specified one
bf	same as `rest`
butfirst	same as `rest`
butlast	discard the last `N` input titles
first	select the first `N` input titles
last	select the last `N` input titles
limit	select the first or last `N` input titles	✓	`!`
next	find which titles in a `list` field follow the input ones
nsort	sort the input by number field		`!`
nsortcs	sort the input titles by number field, treating upper and lower case as different		`!`
nth	select the `N`th input title
order	selectively reverse the input list	✓
previous	find which titles in a `list` field precede the input ones
rest	discard the first `N` input titles
reverse	reverse the order of the input titles
sort	sort the input by text field	✓	`!`
sortan	sort the input by text field considering them as alphanumerics	✓	`!`
sortcs	sort the input by text field, treating upper and lower case as different		`!`
sortsub	sort the input by the result of evaluating a subfilter for each item		`!`
zth	select the `Z`th input title
Listops Operators
allafter	discard all items except those after the marker
allbefore	discard all items except those before the marker
append	append a range of items from an array to the list
cycle	toggle the titles specified in the first parameter in a cyclical manner
insertafter	insert an item `T` into a list immediately after an item `A`
insertbefore	insert an item `T` into a list immediately before an item `B`
move	move marker N places in the list
prepend	prepend a range of items from an array to the list
putafter	move N trailing items after the marker
putbefore	move N trailing items before the marker
putfirst	move N trailing items to the head of the list
putlast	move N leading items to the tail of the list
remove	remove a list of titles specified in the parameter from the input
replace	replace marker with N trailing items
sortby	sort the current list in the order of the list referenced in the parameter
toggle	toggle the title specified in the parameter in the input
unique	remove all duplicate items from the current list
String Operators
addprefix	extend each input title with a prefix
addsuffix	extend each input title with a suffix
applypatches	applies a set of patches to transform the input
compare	filter the input by comparing each item against the parameter		`!`
decodebase64	apply base 64 decoding to a string
decodehtml	apply HTML decoding to a string
decodeuri	apply URI decoding to a string
decodeuricomponent	apply URI component decoding to a string
encodebase64	apply base 64 encoding to a string
encodehtml	apply HTML encoding to a string
encodeuri	apply URI encoding to a string
encodeuricomponent	apply URI component encoding to a string
enlist-input	select titles by interpreting each input title as a title list
escapecss	apply CSS escaping to a selection of titles through the CSS.escape() method / operation
escaperegexp	escape special characters used in regular expressions
format	format the input string according to one of supported formats
jsonstringify	apply JSON string encoding to a string, see also the similar `stringify`
levenshtein	determine the Levenshtein distance of the input title(s) and a given string
makepatches	returns a set of patches that transform the input to a given string
pad	returns each item in the list padded to the specified length
prefix	filter the input titles by how they start		`!`
removeprefix	filter the input titles by how they start, deleting that prefix
removesuffix	filter the input titles by how they end, deleting that suffix
search-replace	returns each item in the list, replacing within each title the string specified by the first parameter with the second parameter
sha256	apply sha256 hash to a string
splitbefore	select a delimited prefix from each input title
stringify	apply JavaScript string encoding to a string, see also the similar `jsonstringify`
substitute	returns each item in the list, replacing within each title placeholders for filters, parameters and variables with their corresponding values
suffix	filter the input titles by how they end		`!`
trim	returns each item in the list with whitespace, or a given character string, trimmed from the start and/or end
Mathematics Operators
abs	calculate the absolute value of a list of numbers
acos	calculate the arccosine value (in radians) of a list of numbers
add	treating each input title as a number, add to each the numeric value of the parameter
asin	calculate the arcsine value (in radians) of a list of numbers
atan	calculate the arctangent value (in radians) of a list of numbers
atan2	returns the angle in the plane (in radians) between the positive x-axis and the ray from (0,0) to the point (x,y), for [`Y`]atan2[`X`]
average	treating each input title as a number, compute their arithmetic mean
ceil	rounds a list of numbers up to the next largest integer
compare	filter the input by comparing each item against the parameter		`!`
cos	calculate the cosine value of a list of angles (given in radians)
divide	treating each input title as a number, divide it by the numeric value of the parameter
exponential	convert each number to exponential notation with `N` digits
fixed	convert each number to fixed point notation with `N` digits after the decimal point
floor	rounds a list of numbers to the largest integer less than or equal to each number
log	treating each input title as a number, return its logarithm with base equal to the numeric value of the parameter if specified, otherwise base `e`
max	treating each input title as a number, take the maximum of its value and the numeric value of the parameter
maxall	find the largest of a list of numbers
median	treating each input title as a number, compute their median value
min	treating each input title as a number, take the minimum of its value and the numeric value of the parameter
minall	find the smallest of a list of numbers
multiply	treating each input title as a number, multiply it by the numeric value of the parameter
negate	calculate the negation of a list of numbers
power	treating each input title as a number, raise it to the power of the numeric value of the parameter
precision	convert each number to a string with `N` significant digits
product	produce the product of the input numbers
remainder	treating each input title as a number, return the remainder when divided by the numeric value of the parameter
round	rounds a list of numbers to the nearest integer
sign	return -1, 0 or 1 for a list of numbers according to whether each number is negative, zero, or positive
sin	calculate the sine value of a list of angles (given in radians)
standard-deviation	treating each input title as a number, compute their standard-deviation
subtract	treating each input title as a number, subtract from each the numeric value of the parameter
sum	produce the sum of the input numbers
tan	calculate the tangent value of a list of angles (given in radians)
trunc	truncates a list of numbers to their integer part, removing any fractional part
untrunc	rounds a list of numbers to the next integer with largest absolute value, that is, away from zero
variance	treating each input title as a number, compute their variance
Tag Operators
tag	filter the input by tag	✓	`!`
tagging	find the tiddlers that have the input tags
tags	select all tags of the input tiddlers
untagged	discard any input titles that have tags		`!`
Special Operators
commands	select the titles of all the Node.js commands			`C`
deserialize	extract JSON representation of tiddlers from the input strings
deserializers				`C`
editiondescription	select the descriptions of the input editions
editions	select the names of all the TiddlyWiki editions			`C`
getvariable	select all values of variables named in the input titles
modulesproperty	retrieve a module property
modules	select the names of all modules of the input module types
moduletypes	select the names of all TiddlyWiki module types			`C`
plugintiddlers	select all shadow titles in the input plugins
shadowsource	select the plugin titles that contain the input shadows
storyviews	select the names of all the story views			`C`
subtiddlerfields	select all fields present in the selected tiddlers within a plugin
variables	select the names of all the actively defined variables			`C`

A typical step is written as [operator[parameter]], although not all of the operators need a parameter.

For the exact rules, see Filter Syntax.