Getting source of a function in hy.. WIP

source.hy

(import re
        linecache
        inspect
        [hy.lex.lexer [lexer]]
        [itertools [count]])


(defmacro getstartlines [f]
  "Gets the starting lines for a given function"
  (if-python2 `(. ~f func-code co-firstlineno)
	      `(. ~f --code-- co-firstlineno)))

(defmacro inc! [var]
  `(setv ~var (inc ~var)))

(defmacro dec! [var]
  `(setv ~var (dec ~var)))

;; Wow! such hack! much crazy!  
;; For starts, failure cases include unbalanced s-expressions
;; (where this function never terminates)
;; Also might fail for regexes that use double quotes inside them
;; (as we have a regex to skip those..kind of brings up xkcd.com/1313)
(defn sourcelines [f]
  "Gets the source of a `function`, as a list"
  (unless (inspect.isfunction f)
    (raise (TypeError (.format  "source only works for functions got % instead" f))))
  (let [[file (inspect.getsourcefile f)]
	[linecount (count (getstartlines f))]
	[parencount 0]
	[lines []]]
    (if (.endswith file ".py")
      (first (inspect.getsourcelines f))
      (do
       (while True
	 (setv line (linecache.getline file (next linecount)))
	 ;; Try to match multiline docstrings..lexer will throw a lex exception
	 ;; otherwise. However source of this function
	 ;; and others using some double quote regexes will fail
	 (unless (re.match r"^(([^\"]*\"){2})*[^\"]*$" line)
	   (continue))
	 (for [token (lexer.lex line)]
	   (cond [(= "LPAREN" (.gettokentype token)) (inc! parencount)]
		 [(= "RPAREN" (.gettokentype token)) (dec! parencount)]))
	 (.append lines line)
	 (when (zero? parencount)
	   (break)))
       lines))))

(defn source [f]
  (.join "" ( sourcelines f)))

(print (source take))
(print (source inspect.getsourcelines))