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janet/lib/pp.dst
Calvin Rose af6e6ded35 Add configurable stack overflow to prevent infinite recursion
without waiting for out of memory.
2018-02-12 11:49:10 -05:00

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(def a (fn [] 2))
#
# Copyright (c) 2017 Calvin Rose
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.
#
# Define a simple pretty printer
(def pp (do
(defn pp-seq [pp seen buf a start end]
(if (get seen a)
(buffer-push-string buf "<cycle>")
(do
(put seen a true)
(def len (length a))
(buffer-push-string buf start)
(for [i 0 len]
(when (not= i 0) (buffer-push-string buf " "))
(pp seen buf (get a i)))
(buffer-push-string buf end)
))
buf)
(defn pp-dict [pp seen buf a start end]
(if (get seen a)
(buffer-push-string buf "<cycle>")
(do
(put seen a true)
(var k (next a nil))
(buffer-push-string buf start)
(while k
(def v (get a k))
(pp seen buf k)
(buffer-push-string buf " ")
(pp seen buf v)
(varset! k (next a k))
(when k (buffer-push-string buf " "))
)
(buffer-push-string buf end)
))
buf)
(def _printers {
:array (fn [pp seen buf x] (pp-seq pp seen buf x "[" "]"))
:tuple (fn [pp seen buf x] (pp-seq pp seen buf x "(" ")"))
:table (fn [pp seen buf x] (pp-dict pp seen buf x "@{" "}"))
:struct (fn [pp seen buf x] (pp-dict pp seen buf x "{" "}"))
})
(defn _default_printer [pp seen buf x]
(buffer-push-string buf (string x))
buf)
(defn pp1 [seen buf x]
(def pmaybe (get _printers (type x)))
(def p (if pmaybe pmaybe _default_printer))
(p pp1 seen buf x))
(fn [x] (print (pp1 @{} @"" x)))))