crustimoney.experimental.combinators — nl.functionalbytes/crustimoney 2.0.0-rc-3-0x8bb5

Experimental combinators. These may get promoted, or changed, or dismissed.

These combinators are not available in the string- or data-driven grammar (yet). To use them with those, combine them in a larger grammar like so:

(require '[crustimoney.combinators :as c]
         '[crustimoney.string-grammar :as sg]
         '[crustimoney.experimental.combinators :as ec])

(merge
 (sg/create-parser
   "root= <- stream
    expr= <- 'BEGIN' [0-9]+ 'END'")
 {:stream (ec/stream* {}
            (c/chain {}
              (ec/with-callback {:callback handle-expr}
                (c/ref {:to :expr}))
              :hard-cut))})

Above example also shows how to setup a streaming parser. The stream* ensures that the result tree does not grow, the with-callback passes chunks of results to a function, before it is hard-cut. The hard-cut ensures both the packrat cache and the streaming reader buffer (if used, see reader namespace) are kept small.

range clj

(range {:keys [min max] :or {max Long/MAX_VALUE}} parser)

Like a repeat, but the times the wrapped parser is matched must lie within the given range. It will not try to parse more than max times. If max is not supplied, there is no maximum.

stream* clj

(stream* _ parser)

Like repeat*, but does does not keep its children. Can be used in combination with with-callback combinator, for example.

stream+ clj

(stream+ _ parser)

Like repeat+, but does does not keep its children. Can be used in combination with with-callback combinator, for example.

with-callback clj

(with-callback {:keys [callback]} parser)

Pushes (success) result of parser to the 2-arity callback function. The callback receives the text and the success result.

If callback is a symbol, it is resolved using requiring-resolve.