clojure-peg
Some code for parsing and generating Clojure source code...using Janet's Parsing Expression Grammar support.
Usage Examples
Basic Parsing and Generation
(import clojure-peg/rewrite)
# parse code string
(rewrite/par "(+ 1 1)")
# =>
'@[:code
(:list
(:symbol "+") (:whitespace " ")
(:number "1") (:whitespace " ")
(:number "1"))]
# generate code string
(rewrite/gen
'@(:map
(:keyword ":a") (:whitespace " ")
(:number "1")))
# =>
"{:a 1}"
# roundtrip
(def src "{:x :y \n :z [:a :b :c]}")
(= (rewrite/gen (rewrite/par src))
src)
# =>
true
# replace underscores in keywords with dashes
(def src-2
"(defn a [] {:a_1 1 :b_2 2})")
(rewrite/gen
(postwalk |(if (and (tuple? $)
(= (first $) :keyword)
(string/find "_" (in $ 1)))
(tuple ;(let [arr (array ;$)]
(put arr 1
(string/replace-all "_" "-" (in $ 1)))))
$)
(rewrite/par src-2)))
# =>
"(defn a [] {:a-1 1 :b-2 2})"
With Location Info
(import clojure-peg/location)
# parse code string
(location/par "(+ 1 1)")
# =>
'@[:code @{:bc 1 :bl 1
:ec 8 :el 1}
(:list @{:bc 1 :bl 1
:ec 8 :el 1}
(:symbol @{:bc 2 :bl 1
:ec 3 :el 1} "+")
(:whitespace @{:bc 3 :bl 1
:ec 4 :el 1} " ")
(:number @{:bc 4 :bl 1
:ec 5 :el 1} "1")
(:whitespace @{:bc 5 :bl 1
:ec 6 :el 1} " ")
(:number @{:bc 6 :bl 1
:ec 7 :el 1} "1"))]
# generate code string
(location/gen
'@[:code @{}
(:list @{}
(:symbol @{} "+")
(:whitespace @{} " ")
(:number @{} "1")
(:whitespace @{} " ")
(:number @{} "1"))])
# =>
"(+ 1 1)"
# roundtrip
(def src "{:x :y \n :z [:a :b :c]}")
(= (location/gen (location/par src))
src)
# =>
true
Roundtrip Testing
To perform roundtrip testing on syntactically valid .clj
files, use
the test-samples.janet
script in the support
directory.
For example, to test all .clj
files in a directory at path /tmp/samples
:
janet support/test-samples.janet /tmp/samples
Individual syntactically valid .clj
files may also be tested by
specifying file paths.
For example, to test sample.clj
that lives under /tmp
:
janet support/test-samples.janet /tmp/sample.clj