No longer rely on PyFunctional's seq.grouped which throws StopIteration (#221)

Author: chrisrink10

src/basilisp/compiler.py

@@ -33,7 +33,7 @@
 from basilisp.lang.runtime import Var
 from basilisp.lang.typing import LispForm
 from basilisp.lang.util import genname, munge
-from basilisp.util import Maybe
+from basilisp.util import Maybe, partition
 
 USE_VAR_INDIRECTION = 'use_var_indirection'
 
@@ -621,7 +621,7 @@ def _assert_recur_is_tail(ctx: CompilerContext, form: lseq.Seq) -> None:  # noqa
                 except IndexError:
                     pass
             elif child.first == _LET:
-                for binding, val in seq(runtime.nth(child, 1)).grouped(2):
+                for binding, val in partition(runtime.nth(child, 1), 2):
                     _assert_no_recur(ctx, lseq.sequence([binding]))
                     _assert_no_recur(ctx, lseq.sequence([val]))
                 let_body = runtime.nthnext(child, 2)
@@ -1048,9 +1048,9 @@ def let_32(a_33, b_34, c_35):
     # the variable names, which become Python locals in an expression context (which
     # is a subtly different Python AST node); and the computed expressions.
     st = ctx.symbol_table
-    bindings = seq(form[1]).grouped(2)
+    bindings = list(partition(form[1], 2))
 
-    if bindings.empty():
+    if not bindings:
         raise CompilerException("Expected at least one binding in 'let*'") from None
 
     arg_syms: Dict[

src/basilisp/lang/map.py

@@ -10,6 +10,7 @@
 from basilisp.lang.meta import Meta
 from basilisp.lang.seq import Seqable, sequence, Seq
 from basilisp.lang.util import lrepr
+from basilisp.util import partition
 
 
 class MapEntry:
@@ -121,7 +122,7 @@ def with_meta(self, meta: "Map") -> "Map":
 
     def assoc(self, *kvs) -> "Map":
         m = self._inner.evolver()
-        for k, v in seq(kvs).grouped(2):
+        for k, v in partition(kvs, 2):
             m[k] = v
         return Map(m.persistent())
 
@@ -199,5 +200,5 @@ def from_entries(entries):
 
 
 def hash_map(*pairs) -> Map:
-    entries = seq(pairs).grouped(2).map(lambda v: MapEntry.of(v[0], v[1])).to_list()
+    entries = seq(partition(pairs, 2)).map(lambda v: MapEntry.of(v[0], v[1])).to_list()
     return from_entries(entries)

src/basilisp/util.py

@@ -87,3 +87,17 @@ def stream(self) -> Sequence:
     @property
     def is_present(self) -> bool:
         return self._inner is not None
+
+
+def partition(coll, n: int):
+    """Partition coll into groups of size n."""
+    assert n > 0
+    start = 0
+    stop = n
+    while stop <= len(coll):
+        yield tuple(e for e in coll[start:stop])
+        start += n
+        stop += n
+    if start < len(coll) < stop:
+        stop = len(coll)
+        yield tuple(e for e in coll[start:stop])

tests/basilisp/util_test.py

@@ -0,0 +1,9 @@
+from basilisp.util import partition
+
+
+def test_partition():
+    assert [(1, 2, 3, 4)] == list(partition([1, 2, 3, 4], 5))
+    assert [(1, 2, 3, 4)] == list(partition([1, 2, 3, 4], 4))
+    assert [(1, 2, 3), (4,)] == list(partition([1, 2, 3, 4], 3))
+    assert [(1, 2), (3, 4)] == list(partition([1, 2, 3, 4], 2))
+    assert [(1,), (2,), (3,), (4,)] == list(partition([1, 2, 3, 4], 1))

tests/basilisp/conftest.py renamed to tests/conftest.py

@@ -1,11 +1,11 @@
 [tox]
-envlist = py36,mypy,lint
+envlist = py36,py37,mypy,lint
 
 [testenv]
 deps =
     six==1.10.0
 commands =
-    pytest --disable-warnings
+    pytest
 
 [testenv:coverage]
 deps =