Merge pull request #202 from paultag/paultag/feature/start-language-lib

Add in a language lib.

.travis.yml

@@ -8,7 +8,7 @@ python:
 # command to install dependencies
 install:
   - pip install -r requirements.txt --use-mirrors
-  - if [[ $TRAVIS_PYTHON_VERSION == '2.6' ]]; then pip install unittest2 astor --use-mirrors; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == '2.6' ]]; then pip install importlib unittest2 astor --use-mirrors; fi
   - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then pip install astor --use-mirrors; fi
   - if [[ $TRAVIS_PYTHON_VERSION == 'pypy' ]]; then pip install astor --use-mirrors; fi
   - python setup.py -q install

hy/compiler.py

@@ -36,14 +36,14 @@ from hy.models.list import HyList
 from hy.models.dict import HyDict
 
 import hy.importer
-from hy.core import process
-
-from hy.util import str_type
 
 from hy.macros import require
+from hy.util import str_type
+from hy.core import process
 
-import codecs
 import traceback
+import importlib
+import codecs
 import ast
 import sys
 
@@ -61,6 +61,17 @@ def compile_time_ns(module_name):
     return ns
 
 
+_stdlib = {}
+
+
+def load_stdlib():
+    import hy.core
+    for module in hy.core.STDLIB:
+        mod = importlib.import_module(module)
+        for e in mod.EXPORTS:
+            _stdlib[e] = module
+
+
 class HyCompileError(HyError):
     def __init__(self, exception, traceback=None):
         self.exception = exception
@@ -339,6 +350,9 @@ class HyASTCompiler(object):
         self.anon_var_count = 0
         self.imports = defaultdict(set)
         self.module_name = module_name
+        if not module_name.startswith("hy.core"):
+            # everything in core needs to be explicit.
+            load_stdlib()
 
     def get_anon_var(self):
         self.anon_var_count += 1
@@ -1432,6 +1446,10 @@ class HyASTCompiler(object):
             ret = self.compile_atom(fn, expression)
             if ret:
                 return ret
+
+            if fn in _stdlib:
+                self.imports[_stdlib[fn]].add(fn)
+
             if fn.startswith("."):
                 # (.split "test test") -> "test test".split()
 

hy/core/__init__.py

@@ -24,6 +24,10 @@ MACROS = [
     "hy.core.bootstrap",
 ]
 
+STDLIB = [
+    "hy.core.language"
+]
+
 
 def process(tree, module_name):
     load_macros()

hy/core/bootstrap.py

@@ -137,21 +137,6 @@ def let_macro(variables, *body):
     return HyExpression([expr + list(body)])
 
 
-@macro("take")
-def take_macro(n, lst):
-    return HyExpression([HySymbol('slice'),
-                         lst,
-                         HyInteger(0),
-                         HyInteger(n)])
-
-
-@macro("drop")
-def drop_macro(n, lst):
-    return HyExpression([HySymbol('slice'),
-                         lst,
-                         HyInteger(n)])
-
-
 @macro("when")
 def when_macro(test, *body):
     return HyExpression([

hy/core/language.hy

@@ -0,0 +1,22 @@
+;;;; This contains some of the core Hy functions used
+;;;; to make functional programming slightly easier.
+;;;;
+
+
+(defn take [count what]
+  "Take `count` elements from `what`, or the whole set if the total
+   number of entries in `what` is less than `count`."
+  (setv what (iter what))
+  (for [i (range count)]
+    (yield (next what))))
+
+
+(defn drop [count coll]
+  "Drop `count` elements from `coll` and return the iter"
+  (let [ [citer (iter coll)] ]
+    (for [i (range count)]
+      (next citer))
+    citer))
+
+
+(def *exports* ["take" "drop"])

tests/native_tests/language.hy

@@ -385,9 +385,9 @@
 
 (defn test-drop []
   "NATIVE: test drop"
-  (assert (= (drop 0 [2 3]) [2 3]))
-  (assert (= (drop 1 [2 3]) [3]))
-  (assert (= (drop 2 [2 3]) [])))
+  (assert (= (list (drop 0 [2 3])) [2 3]))
+  (assert (= (list (drop 1 [2 3])) [3]))
+  (assert (= (list (drop 2 [2 3])) [])))
 
 
 (defn test-rest []
@@ -741,6 +741,13 @@
   (assert (= "test" (:foo {:foo "test"}))))
 
 
+(defn test-take []
+  "NATIVE: test the take operator"
+  (assert (= [1 2 3] (list (take 3 [1 2 3]))))
+  (assert (= [1 2 3] (list (take 4 [1 2 3]))))
+  (assert (= [1 2] (list (take 2 [1 2 4])))))
+
+
 (defn test-break-breaking []
   "NATIVE: test checking if break actually breaks"
   (defn holy-grail [] (for [x (range 10)] (if (= x 5) (break))) x)

tox.ini

@@ -26,6 +26,7 @@ deps =
  nose
  setuptools
  unittest2
+ importlib
 
 [testenv:flake8]
 deps = flake8