Selectors syntax

selector

[selector-step (:>? selector-step)*]

#{selector*} ; grouping

a-symbol ; must evaluate to a state-machine

(some clojure code) ; must evaluate to a state-machine

selector-step

:a-keyword ; can be :* :.class :tag :#id or any combination eg :div#foo.bar.baz

#{selector-step*} ; union

[selector-step*] ; intersection

a-symbol ; must evaluate to a state-machine — some are already defined

(some clojure code) ; must evaluate to a state-machine — better built using some predefined functions, predicate builders or macros

Predefined selector-steps

root, first-child,
last-child,
first-of-type,
last-of-type,
only-child,
only-of-type,
void (CSS’s :empty),
odd and even.

Predefined functions

attr? CSS

(attr? attribute-keyword*)

sample usage:

(attr? :href) ; *[href]
(attr? :href :title) ; *[href][title]

attr= CSS

(attr= (attribute-keyword value)*)

sample usage:

(attr= :href "foo") ; *[href=foo]
(attr= :href "foo" :title "bar") ; *[href=foo][title=bar]

attr-has CSS

(attr-has (attribute-keyword value)*)

sample usage:

(attr-has :foo "bar" "baz") ; *[foo~=bar][foo~=baz]

attr-starts CSS

(attr-starts (attribute-keyword value)*)

sample usage:

(attr-starts :href "foo" :title "bar"); *[href^=foo][title^=bar]

attr-ends CSS

(attr-ends (attribute-keyword value)*)

sample usage:

(attr-ends :href "foo" :title "bar") ; *[href$=foo][title$=bar]

attr-contains CSS

(attr-contains (attribute-keyword value)*)

sample usage:

(attr-contains :href "foo" :title "bar") ; *[href*=foo][title*=bar]

attr|= CSS

(attr|= (attribute-keyword value)*)

sample usage:

(attr|= :lang "fr") ; *[lang|=fr]

nth-child CSS

(nth-child stride? offset)

sample usage:

(nth-child 3) ; *:nth-child(3)
(nth-child 4 2) ; *:nth-child(4n+2)

nth-last-child CSS

(nth-last-child stride? offset)

sample usage:

(nth-last-child 3) ; *:nth-last-child(3)
(nth-last-child 4 2) ; *:nth-last-child(4n+2)

nth-of-type CSS

(nth-of-type stride? offset)

sample usage:

(nth-of-type 3) ; *:nth-of-type(3)
(nth-of-type 4 2) ; *:nth-of-type(4n+2)

nth-last-of-type CSS

(nth-last-of-type stride? offset)

sample usage:

(nth-last-of-type 3) ; *:nth-last-of-type(3)
(nth-last-of-type 4 2) ; *:nth-last-of-type(4n+2)

but CSS

(but selector-step)

sample usage:

(but :a) ; :not(a)

has

(has selector)

sample usage:

(has [:a])

Predicate builders

These functions take a predicate and return a state-machine.

pred

(pred predicate-on-elements)

sample usage:

(pred #(= (:tag %) tag-name))

text-pred

(text-pred predicate-on-text-nodes)

sample usage:

(text-pred #(re-matches #“\d+” %))

zip-pred

(zip-pred predicate-on-elements-locs)

sm/pred (where sm aliases net.cgrand.enlive-html.state-machine)

(sm/pred predicate-on-locs)

Useful macros

selector takes a selector and evaluates to a state-machine, selector-step takes a selector-step and evaluates to a state-machine.
They are backed by compile-selector and compile-step.