robertluo.pullable.core — robertluo/pullable 0.3.112

Implementation of queries.

A query is a function which can extract k v from data.

accept clj

(accept f-conj x k v)

General acceptor function design: when k is nil, means there is no match, current progress should fail; when v is nil, means there is no value.

• funcition f-conj, takes two argements, coll and a k-v pair
• x is the collection willing to accept

apply-post clj multimethod

create a post processor by ::pp-type, returns a function takes k-v pair, returns the same shape of data

assert-arg! clj

(assert-arg! pred arg)

an error that represent apply-post illegal argument

data-error! clj

(data-error! reason k data)

throw an exception specify data error

decorate-query clj

(decorate-query q pp-pairs)

filter-query clj

(filter-query q pred)

returns a filter query which will not appears in result data, but will void other query if in a vector query, pred is the filter condition

fn-query clj

(fn-query k)

(fn-query k f)

(fn-query k f child)

returns a simple query has key as k, f to return a value from a map, and child query to execute if matches.

map-acceptor clj

common acceptor using an empty map to accept

mk-named-var-query clj

(mk-named-var-query t-sym-table sym)

(mk-named-var-query t-sym-table status sym)

returns a factory function which take a query q as its argument.

named-var-factory clj

(named-var-factory)

returns a function takes a symbol as the argument, returns a named-var-query

post-process-query clj

(post-process-query child f-post-process)

A query decorator post process its result

pq clj

construct a general query:

• id key of this query
• acceptor default acceptor of this query, used when no acceptor specified when invoke
• val-getter is the function to extract data

PullQuery clj

run-bind clj

(run-bind f-query data)

f-query takes a function (returned by named-var-factory) as argument, returns a query, then run it on data, finally returns a vector:

• query result
• named variable binding map

run-query clj

(run-query q data)

run a query q on data, returns the query result function.

A query result function has one argument of acceptor, which is another function takes k, v as arguments. The acceptor can be nil, means that the query are free to construct the result.

sconj clj

commonn acceptor using conj

seq-query clj

(seq-query qr)

returns a seq-query which applies query q to data (must be a collection) and return

term-query clj

(term-query v)

identity query

val-acceptor clj

(val-acceptor _ v)

identity acceptor, ignore k, only return v

vector-query clj

(vector-query queries)

returns a vector query, takes other queries as its children, then apply them to data, return the merged map.