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added for and with macros

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Fixed up anaphoric.hy and added the tests too native_tests/__init__.py

added __init__.hy
This commit is contained in:
Foxboron 2013-11-10 19:00:01 +01:00
parent f189f0a457
commit d82636958b
11 changed files with 160 additions and 105 deletions
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52
docs/language/api.rst
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@ -441,52 +441,36 @@ first / car
for
---
`for` macro is used to build nested `foreach` loops. The macro takes two
parameters, first being a vector specifying collections to iterate over and
variables to bind. The second parameter is a statement which is executed during
each loop:
.. code-block:: clj
(for [x iter y iter] stmt)
(foreach [x iter]
(foreach [y iter] stmt))
foreach
-------
`foreach` is used to call a function for each element in a list or vector.
`for` is used to call a function for each element in a list or vector.
Results are discarded and None is returned instead. Example code iterates over
collection and calls side-effect to each element in the collection:
.. code-block:: clj
;; assuming that (side-effect) is a function that takes a single parameter
(foreach [element collection] (side-effect element))
(for [[element collection]] (side-effect element))
;; foreach can have an optional else block
(foreach [element collection] (side-effect element)
(else (side-effect-2)))
;; for can have an optional else block
(for [[element collection]] (side-effect element)
(else (side-effect-2)))
The optional `else` block is executed only if the `foreach` loop terminates
The optional `else` block is executed only if the `for` loop terminates
normally. If the execution is halted with `break`, the `else` does not execute.
.. code-block:: clj
=> (foreach [element [1 2 3]] (if (< element 3)
... (print element)
... (break))
=> (for [[element [1 2 3]]] (if (< element 3)
... (print element)
... (break))
... (else (print "loop finished")))
1
2
=> (foreach [element [1 2 3]] (if (< element 4)
... (print element)
... (break))
=> (for [[element [1 2 3]]] (if (< element 4)
... (print element)
... (break))
... (else (print "loop finished")))
1
2
@ -635,7 +619,7 @@ function is defined and passed to another function for filtering output.
... {:name "Dave" :age 5}])
=> (defn display-people [people filter]
... (foreach [person people] (if (filter person) (print (:name person)))))
... (for [[person people]] (if (filter person) (print (:name person)))))
=> (display-people people (fn [person] (< (:age person) 25)))
Alice
@ -949,16 +933,18 @@ context to an argument or ignore it completely, as shown below:
.. code-block:: clj
(with [arg (expr)] block)
(with [[arg (expr)]] block)
(with [(expr)] block)
(with [[(expr)]] block)
(with [[arg (expr)] [(expr)]] block)
The following example will open file `NEWS` and print its content on screen. The
file is automatically closed after it has been processed.
.. code-block:: clj
(with [f (open "NEWS")] (print (.read f)))
(with [[f (open "NEWS")]] (print (.read f)))
with-decorator
@ -996,7 +982,7 @@ infinite series without consuming infinite amount of memory.
.. code-block:: clj
=> (defn multiply [bases coefficients]
... (foreach [(, base coefficient) (zip bases coefficients)]
... (for [[(, base coefficient) (zip bases coefficients)]]
... (yield (* base coefficient))))
=> (multiply (range 5) (range 5))

33
hy/compiler.py
View File

@ -1177,14 +1177,18 @@ class HyASTCompiler(object):
fn.stmts[-1].decorator_list = decorators
return ret + fn
@builds("with")
@builds("with*")
@checkargs(min=2)
def compile_with_expression(self, expr):
expr.pop(0) # with
expr.pop(0) # with*
args = expr.pop(0)
if len(args) > 2 or len(args) < 1:
raise HyTypeError(expr, "with needs [arg (expr)] or [(expr)]")
if not isinstance(args, HyList):
raise HyTypeError(expr,
"with expects a list, received `{0}'".format(
type(args).__name__))
if len(args) < 1:
raise HyTypeError(expr, "with needs [[arg (expr)]] or [[(expr)]]]")
args.reverse()
ctx = self.compile(args.pop(0))
@ -1623,23 +1627,36 @@ class HyASTCompiler(object):
result += ld_name
return result
@builds("foreach")
@builds("for*")
@checkargs(min=1)
def compile_for_expression(self, expression):
expression.pop(0) # for
target_name, iterable = expression.pop(0)
args = expression.pop(0)
if not isinstance(args, HyList):
raise HyTypeError(expression,
"for expects a list, received `{0}'".format(
type(args).__name__))
try:
target_name, iterable = args
except ValueError:
raise HyTypeError(expression,
"for requires two forms in the list")
target = self._storeize(self.compile(target_name))
ret = Result()
orel = Result()
# (foreach [] body (else …))
# (for* [] body (else …))
if expression and expression[-1][0] == HySymbol("else"):
else_expr = expression.pop()
if len(else_expr) > 2:
raise HyTypeError(
else_expr,
"`else' statement in `foreach' is too long")
"`else' statement in `for' is too long")
elif len(else_expr) == 2:
orel += self.compile(else_expr[1])
orel += orel.expr_as_stmt()

10
hy/contrib/anaphoric.hy
View File

@ -31,14 +31,14 @@
(defmacro ap-each [lst &rest body]
"Evaluate the body form for each element in the list."
`(foreach [it ~lst] ~@body))
`(for [[it ~lst]] ~@body))
(defmacro ap-each-while [lst form &rest body]
"Evalutate the body form for each element in the list while the
predicate form evaluates to True."
`(let [[p (lambda [it] ~form)]]
(foreach [it ~lst]
(for [[it ~lst]]
(if (p it)
~@body
(break)))))
@ -47,7 +47,7 @@
(defmacro ap-map [form lst]
"Yield elements evaluated in the form for each element in the list."
`(let [[f (lambda [it] ~form)]]
(foreach [v ~lst]
(for [[v ~lst]]
(yield (f v)))))
@ -55,7 +55,7 @@
"Yield elements evaluated for each element in the list when the
predicate function returns True."
`(let [[f (lambda [it] ~rep)]]
(foreach [it ~lst]
(for [[it ~lst]]
(if (~predfn it)
(yield (f it))
(yield it)))))
@ -64,7 +64,7 @@
(defmacro ap-filter [form lst]
"Yield elements returned when the predicate form evaluates to True."
`(let [[pred (lambda [it] ~form)]]
(foreach [val ~lst]
(for [[val ~lst]]
(if (pred val)
(yield val)))))

4
hy/core/bootstrap.hy
View File

@ -34,7 +34,7 @@
(defmacro defmacro-alias [names lambda-list &rest body]
"define one macro with several names"
(setv ret `(do))
(foreach [name names]
(for* [name names]
(.append ret
`(defmacro ~name ~lambda-list ~@body)))
ret)
@ -52,7 +52,7 @@
(setv macroed_variables [])
(if (not (isinstance variables HyList))
(macro-error variables "let lexical context must be a list"))
(foreach [variable variables]
(for* [variable variables]
(if (isinstance variable HyList)
(do
(if (!= (len variable) 2)

28
hy/core/language.hy
View File

@ -33,11 +33,11 @@
(defn cycle [coll]
"Yield an infinite repetition of the items in coll"
(setv seen [])
(foreach [x coll]
(for* [x coll]
(yield x)
(.append seen x))
(while seen
(foreach [x seen]
(for* [x seen]
(yield x))))
(defn dec [n]
@ -49,7 +49,7 @@
"Return a generator from the original collection with duplicates
removed"
(let [[seen []] [citer (iter coll)]]
(foreach [val citer]
(for* [val citer]
(if (not_in val seen)
(do
(yield val)
@ -58,7 +58,7 @@
(defn drop [count coll]
"Drop `count` elements from `coll` and yield back the rest"
(let [[citer (iter coll)]]
(try (foreach [i (range count)]
(try (for* [i (range count)]
(next citer))
(catch [StopIteration]))
citer))
@ -66,10 +66,10 @@
(defn drop-while [pred coll]
"Drop all elements of `coll` until `pred` is False"
(let [[citer (iter coll)]]
(foreach [val citer]
(for* [val citer]
(if (not (pred val))
(do (yield val) (break))))
(foreach [val citer]
(for* [val citer]
(yield val))))
(defn empty? [coll]
@ -84,7 +84,7 @@
(defn filter [pred coll]
"Return all elements from `coll` that pass `pred`"
(let [[citer (iter coll)]]
(foreach [val citer]
(for* [val citer]
(if (pred val)
(yield val)))))
@ -96,7 +96,7 @@
(defn _flatten [coll result]
(if (and (iterable? coll) (not (string? coll)))
(do (foreach [b coll]
(do (for* [b coll]
(_flatten b result)))
(.append result coll))
result)
@ -187,7 +187,7 @@
(defn remove [pred coll]
"Return coll with elements removed that pass `pred`"
(let [[citer (iter coll)]]
(foreach [val citer]
(for* [val citer]
(if (not (pred val))
(yield val)))))
@ -195,7 +195,7 @@
"Yield x forever or optionally n times"
(if (none? n)
(setv dispatch (fn [] (while true (yield x))))
(setv dispatch (fn [] (foreach [_ (range n)] (yield x)))))
(setv dispatch (fn [] (for* [_ (range n)] (yield x)))))
(dispatch))
(defn repeatedly [func]
@ -223,7 +223,7 @@
"Take `count` elements from `coll`, or the whole set if the total
number of entries in `coll` is less than `count`."
(let [[citer (iter coll)]]
(foreach [_ (range count)]
(for* [_ (range count)]
(yield (next citer)))))
(defn take-nth [n coll]
@ -231,16 +231,16 @@
raises ValueError for (not (pos? n))"
(if (pos? n)
(let [[citer (iter coll)] [skip (dec n)]]
(foreach [val citer]
(for* [val citer]
(yield val)
(foreach [_ (range skip)]
(for* [_ (range skip)]
(next citer))))
(raise (ValueError "n must be positive"))))
(defn take-while [pred coll]
"Take all elements while `pred` is true"
(let [[citer (iter coll)]]
(foreach [val citer]
(for* [val citer]
(if (pred val)
(yield val)
(break)))))

33
hy/core/macros.hy
View File

@ -26,17 +26,24 @@
;;; They are automatically required in every module, except inside hy.core
(defmacro for [args &rest body]
"shorthand for nested foreach loops:
(for [x foo y bar] baz) ->
(foreach [x foo]
(foreach [y bar]
"shorthand for nested for loops:
(for [[x foo] [y bar]] baz) ->
(for* [x foo]
(for* [y bar]
baz))"
;; TODO: that signature sucks.
;; (for [[x foo] [y bar]] baz) would be more consistent
(if (% (len args) 2)
(macro-error args "for needs an even number of elements in its first argument"))
(if args
`(foreach [~(.pop args 0) ~(.pop args 0)] (for ~args ~@body))
`(for* ~(.pop args 0) (for ~args ~@body))
`(do ~@body)))
(defmacro with [args &rest body]
"shorthand for nested for* loops:
(with [[x foo] [y bar]] baz) ->
(with* [x foo]
(with* [y bar]
baz))"
(if args
`(with* ~(.pop args 0) (with ~args ~@body))
`(do ~@body)))
@ -71,7 +78,7 @@
(setv root (check-branch branch))
(setv latest-branch root)
(foreach [branch branches]
(for* [branch branches]
(setv cur-branch (check-branch branch))
(.append latest-branch cur-branch)
(setv latest-branch cur-branch))
@ -81,7 +88,7 @@
(defmacro -> [head &rest rest]
;; TODO: fix the docstring by someone who understands this
(setv ret head)
(foreach [node rest]
(for* [node rest]
(if (not (isinstance node HyExpression))
(setv node `(~node)))
(.insert node 1 ret)
@ -92,7 +99,7 @@
(defmacro ->> [head &rest rest]
;; TODO: fix the docstring by someone who understands this
(setv ret head)
(foreach [node rest]
(for* [node rest]
(if (not (isinstance node HyExpression))
(setv node `(~node)))
(.append node ret)
@ -113,7 +120,7 @@
(defmacro yield-from [iterable]
"Yield all the items from iterable"
(let [[x (gensym)]]
`(foreach [~x ~iterable]
`(for* [~x ~iterable]
(yield ~x))))
(defmacro with-gensyms [args &rest body]

1
tests/__init__.py
View File

@ -12,4 +12,5 @@ from .native_tests.when import * # noqa
from .native_tests.with_decorator import * # noqa
from .native_tests.core import * # noqa
from .native_tests.reader_macros import * # noqa
from .native_tests.with_test import * # noqa
from .native_tests.contrib.anaphoric import * # noqa

18
tests/compilers/test_ast.py
View File

@ -295,9 +295,9 @@ def test_ast_bad_assoc():
def test_ast_bad_with():
"Make sure AST can't compile invalid with"
cant_compile("(with)")
cant_compile("(with [])")
cant_compile("(with [] (pass))")
cant_compile("(with*)")
cant_compile("(with* [])")
cant_compile("(with* [] (pass))")
def test_ast_valid_while():
@ -305,14 +305,14 @@ def test_ast_valid_while():
can_compile("(while foo bar)")
def test_ast_valid_foreach():
"Make sure AST can compile valid foreach"
can_compile("(foreach [a 2])")
def test_ast_valid_for():
"Make sure AST can compile valid for"
can_compile("(for [[a 2]])")
def test_ast_invalid_foreach():
"Make sure AST can't compile invalid foreach"
cant_compile("(foreach [a 1] (else 1 2))")
def test_ast_invalid_for():
"Make sure AST can't compile invalid for"
cant_compile("(for* [a 1] (else 1 2))")
def test_ast_expression_basics():

36
tests/native_tests/language.hy
View File

@ -31,12 +31,12 @@
(defn test-for-loop []
"NATIVE: test for loops?"
(setv count 0)
(for [x [1 2 3 4 5]]
(for [[x [1 2 3 4 5]]]
(setv count (+ count x)))
(assert (= count 15))
(setv count 0)
(for [x [1 2 3 4 5]
y [1 2 3 4 5]]
(for [[x [1 2 3 4 5]]
[y [1 2 3 4 5]]]
(setv count (+ count x y)))
(assert (= count 150)))
@ -394,9 +394,9 @@
(defn test-yield []
"NATIVE: test yielding"
(defn gen [] (for [x [1 2 3 4]] (yield x)))
(defn gen [] (for [[x [1 2 3 4]]] (yield x)))
(setv ret 0)
(for [y (gen)] (setv ret (+ ret y)))
(for [[y (gen)]] (setv ret (+ ret y)))
(assert (= ret 10)))
@ -439,37 +439,37 @@
(defn test-context []
"NATIVE: test with"
(with [fd (open "README.md" "r")] (assert fd))
(with [(open "README.md" "r")] (do)))
(with [[fd (open "README.md" "r")]] (assert fd))
(with [[(open "README.md" "r")]] (do)))
(defn test-with-return []
"NATIVE: test that with returns stuff"
(defn read-file [filename]
(with [fd (open filename "r")] (.read fd)))
(with [[fd (open filename "r")]] (.read fd)))
(assert (!= 0 (len (read-file "README.md")))))
(defn test-for-doodle []
"NATIVE: test for-do"
(do (do (do (do (do (do (do (do (do (setv (, x y) (, 0 0)))))))))))
(foreach [- [1 2]]
(for [[- [1 2]]]
(do
(setv x (+ x 1))
(setv y (+ y 1))))
(assert (= y x 2)))
(defn test-foreach-else []
"NATIVE: test foreach else"
(defn test-for-else []
"NATIVE: test for else"
(let [[x 0]]
(foreach [a [1 2]]
(for* [a [1 2]]
(setv x (+ x a))
(else (setv x (+ x 50))))
(assert (= x 53)))
(let [[x 0]]
(foreach [a [1 2]]
(for* [a [1 2]]
(setv x (+ x a))
(else))
(assert (= x 3))))
@ -636,7 +636,7 @@
(defn test-nested-if []
"NATIVE: test nested if"
(for [x (range 10)]
(for [[x (range 10)]]
(if (in "foo" "foobar")
(do
(if true true true))
@ -800,16 +800,16 @@
(defn test-break-breaking []
"NATIVE: test checking if break actually breaks"
(defn holy-grail [] (for [x (range 10)] (if (= x 5) (break))) x)
(defn holy-grail [] (for [[x (range 10)]] (if (= x 5) (break))) x)
(assert (= (holy-grail) 5)))
(defn test-continue-continuation []
"NATIVE: test checking if continue actually continues"
(setv y [])
(for [x (range 10)]
(if (!= x 5)
(continue))
(for [[x (range 10)]]
(if (!= x 5)
(continue))
(.append y x))
(assert (= y [5])))

6
tests/native_tests/native_macros.hy
View File

@ -56,7 +56,7 @@
(defn test-midtree-yield-in-for []
"NATIVE: test yielding in a for with a return"
(defn kruft-in-for []
(for [i (range 5)]
(for* [i (range 5)]
(yield i))
(+ 1 2)))
@ -72,7 +72,7 @@
(defn test-multi-yield []
"NATIVE: testing multiple yields"
(defn multi-yield []
(for [i (range 3)]
(for* [i (range 3)]
(yield i))
(yield "a")
(yield "end"))
@ -97,7 +97,7 @@
(defn test-yield-from []
"NATIVE: testing yield from"
(defn yield-from-test []
(for [i (range 3)]
(for* [i (range 3)]
(yield i))
(yield-from [1 2 3]))
(assert (= (list (yield-from-test)) [0 1 2 1 2 3])))

44
tests/native_tests/with_test.hy Normal file
View File

@ -0,0 +1,44 @@
(defclass WithTest [object]
[(--init--
(fn [self val]
(setv self.val val)
None))
(--enter--
(fn [self]
self.val))
(--exit--
(fn [self type value traceback]
(setv self.val None)))])
(defn test-single-with []
"NATIVE: test a single with"
(with [[t (WithTest 1)]]
(assert (= t 1))))
(defn test-two-with []
"NATIVE: test two withs"
(with [[t1 (WithTest 1)]
[t2 (WithTest 2)]]
(assert (= t1 1))
(assert (= t2 2))))
(defn test-thrice-with []
"NATIVE: test three withs"
(with [[t1 (WithTest 1)]
[t2 (WithTest 2)]
[t3 (WithTest 3)]]
(assert (= t1 1))
(assert (= t2 2))
(assert (= t3 3))))
(defn test-quince-with []
"NATIVE: test four withs, one with no args"
(with [[t1 (WithTest 1)]
[t2 (WithTest 2)]
[t3 (WithTest 3)]
[(WithTest 4)]]
(assert (= t1 1))
(assert (= t2 2))
(assert (= t3 3))))