Fix issue where AST could be generated twice, causing mismatches (#88)

* Fix issue where AST could be generated twice, causing mismatches

* Satisfy the type checker

Author: chrisrink10

basilisp/compiler.py

@@ -1347,12 +1347,14 @@ def _collection_literal_ast(ctx: CompilerContext,
                             form: Iterable[LispForm]) -> Tuple[ASTStream, PyASTStream]:
     """Turn a collection literal of Lisp forms into Python AST nodes, filtering
     out empty nodes."""
-    orig = seq(form) \
-        .map(lambda x: _to_ast(ctx, x)) \
-        .map(_nodes_and_exprl)
-
-    return (orig.flat_map(lambda x: x[0]).to_list(),
-            orig.flat_map(lambda x: x[1]).map(_unwrap_node).to_list())
+    deps: List[ASTNode] = []
+    nodes = []
+    for f in form:
+        depnodes, exprl = _nodes_and_exprl(_to_ast(ctx, f))
+        deps.extend(depnodes)
+        nodes.extend(_unwrap_nodes(exprl))
+
+    return deps, nodes
 
 
 def _with_loc(f: ASTProcessor) -> ASTProcessor:

tests/compiler_test.py

@@ -273,6 +273,13 @@ def test_if(ns_var: Var):
     assert lcompile("(if nil :a :b)") == kw.keyword("b")
     assert lcompile("(if true (if false :a :c) :b)") == kw.keyword("c")
 
+    code = """
+    (def f (fn* [s] s))
+
+    (f (if true \"YELLING\" \"whispering\"))
+    """
+    assert "YELLING" == lcompile(code)
+
 
 def test_interop_call(ns_var: Var):
     assert lcompile('(. "ALL-UPPER" lower)') == "all-upper"