zachallaun

import re
import collections

Failure = collections.namedtuple("Failure", ["unparsed"])

def failure(unparsed=None):
    return Failure(unparsed)

def isfailure(val):
    return isinstance(val, Failure)

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#| #| #| #| #|

Building List Comprehensions from Scratch

#| #|

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(defmacro list-comp (bindings body)
  (cond
   ((= 0 (length bindings))
    `(list ,body))
   ((eq :when (caar bindings))
    `(if ,(cadar bindings)
         (list-comp ,(cdr bindings) ,body)))
   (t `(apply #'append (mapcar (lambda (,(caar bindings))
                                 (list-comp ,(cdr bindings) ,body))
                               ,(cadar bindings))))))

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NUMS = ['10', '9', '8', '7', '6', '5', '4', '3', '2', '1']
OPS = ['', '+', '-', '*', '/']

def interpositions(seq, divs):
    if len(seq) == 1:
        return [seq]
    return ([seq[0], div] + interposed for interposed in interpositions(seq[1:], divs)
                                       for div in divs)

print([''.join(interposed) for interposed in interpositions(NUMS, OPS) if eval(''.join(interposed)) == 2013])

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julia> function transform(ex)
         :(println("transformed"); $(esc(ex)))
       end
# methods for generic function transform
transform(ex) at none:2

julia> macro t(ex)
         transform(ex)
       end

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# Using @async

immutable Continuation
    args
end
cont(args...) = Continuation(args)

immutable Actor
    ref::RemoteRef
    mailbox::RemoteRef

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#| #| #| #| #|

Building List Comprehensions from Scratch

... now with syntax!!!

#|

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# time
# ====

macro time(ex)
    quote
        local t0 = time_ns()
        local val = $(esc(ex))
        local t1 = time_ns()
        println("elapsed time: ", (t1-t0)/1e9, " seconds")
        val

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remove_quote_block(val) = val
remove_quote_block(ex::Expr) =
    ex.head == :block && length(ex.args) == 2 ? ex.args[2] : ex
remove_quote_block(exs...) = map(remove_quote_block, exs)


function syntax_bindings(ex, template::Symbol, collected::Dict)
    s = string(template)
    if s[1] == '_' && s[end] == '_'
        collected[template] = ex

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module Unify

using FunctionalCollections

export unify, extended, lvar, Anything

const _LogicVarKey = 0x1f75f6e80ac3828f

immutable LogicVar
    name