From fc3a33f825ee2f6e81430d0f17507a94308ea6b3 Mon Sep 17 00:00:00 2001
From: Christopher Rink <chrisrink10@gmail.com>
Date: Sun, 28 Jul 2019 22:10:46 -0400
Subject: [PATCH] Fix some things

---
 src/basilisp/core.lpy                  | 18 ++++++++++++++++--
 src/basilisp/lang/compiler/analyzer.py |  7 ++++---
 src/basilisp/lang/reader.py            |  1 +
 tests/basilisp/core_macros_test.lpy    |  6 ++++++
 4 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/basilisp/core.lpy b/src/basilisp/core.lpy
index de8e4392..c490b655 100644
--- a/src/basilisp/core.lpy
+++ b/src/basilisp/core.lpy
@@ -1947,9 +1947,23 @@
 
 (defmacro ..
   "Expand into nested method calls on the returned objects from previous
-  method calls."
+  method calls.
+
+  Successive method invocations are represented as successive lists:
+
+    (.. \"abc\" (lower))              ;=> (. \"abc\" lower)
+    (.. \"abc\" lower (split \",\"))  ;=> (. (. \"abc\" lower) split \",\")
+
+  Methods invoked without arguments may be supplied as bare symbols."
   [x & method-calls]
-  )
+  (if (seq method-calls)
+    (let [joining (first method-calls)]
+      `(..
+        ~(if (seq? joining)
+           (apply list '. x joining)
+           (list '. x joining))
+        ~@(rest method-calls)))
+    x))
 
 (defmacro new
   "Create a new instance of class with args.
diff --git a/src/basilisp/lang/compiler/analyzer.py b/src/basilisp/lang/compiler/analyzer.py
index 05bdcb22..89aee106 100644
--- a/src/basilisp/lang/compiler/analyzer.py
+++ b/src/basilisp/lang/compiler/analyzer.py
@@ -138,6 +138,7 @@
 # Constants used in analyzing
 AS = kw.keyword("as")
 IMPLEMENTS = kw.keyword("implements")
+ns_name_chars = re.compile(r"\w|-|\+|\*|\?|/|\=|\\|!|&|%|>|<|\$")
 _BUILTINS_NS = "python"
 
 # Symbols to be ignored for unused symbol warnings
@@ -2048,7 +2049,7 @@ def _list_node(ctx: AnalyzerContext, form: ISeq) -> Node:
             return handle_special_form(ctx, form)
         elif s.name.startswith(".-"):
             return _host_prop_ast(ctx, form)
-        elif s.name.startswith("."):
+        elif s.name.startswith(".") and reader.name_chars.match(s.name[1:]):
             return _host_call_ast(ctx, form)
 
     return _invoke_ast(ctx, form)
@@ -2094,7 +2095,7 @@ def __resolve_namespaced_symbol(  # pylint: disable=too-many-branches
             form=form, class_=class_, target=target, env=ctx.get_node_env()
         )
 
-    if "." in form.name:
+    if "." in form.name and form.name != "..":
         raise AnalyzerException(
             "symbol names may not contain the '.' operator", form=form
         )
@@ -2206,7 +2207,7 @@ def _resolve_sym(
     #   (Classname. *args)
     #   (aliased.Classname. *args)
     #   (fully.qualified.Classname. *args)
-    if form.ns is None and form.name.endswith("."):
+    if form.ns is None and form.name.endswith(".") and form.name != "..":
         try:
             ns, name = form.name[:-1].rsplit(".", maxsplit=1)
             form = sym.symbol(name, ns=ns)
diff --git a/src/basilisp/lang/reader.py b/src/basilisp/lang/reader.py
index 26bcac61..8c5f5b3e 100644
--- a/src/basilisp/lang/reader.py
+++ b/src/basilisp/lang/reader.py
@@ -51,6 +51,7 @@
 from basilisp.util import Maybe, partition
 
 ns_name_chars = re.compile(r"\w|-|\+|\*|\?|/|\=|\\|!|&|%|>|<|\$|\.")
+name_chars = re.compile(r"\w|-|\+|\*|\?|/|\=|\\|!|&|%|>|<|\$")
 alphanumeric_chars = re.compile(r"\w")
 begin_num_chars = re.compile(r"[0-9\-]")
 num_chars = re.compile("[0-9]")
diff --git a/tests/basilisp/core_macros_test.lpy b/tests/basilisp/core_macros_test.lpy
index adc5508d..dbd0b455 100644
--- a/tests/basilisp/core_macros_test.lpy
+++ b/tests/basilisp/core_macros_test.lpy
@@ -232,6 +232,12 @@
   (is (= nil (comment 1)))
   (is (= nil (comment [1 2 3]))))
 
+(deftest double-dot-test
+  (is (= "abc" (.. "abc")))
+  (is (= "ABC" (.. "abc" (upper))))
+  (is (not (.. "abc" (upper) (islower))))
+  (is (= #py ["A" "B" "C"] (.. "a,b,c" upper (split ",")))))
+
 (deftest if-let-test
   (is (= :a (if-let [a :a] a :b)))
   (is (= 2 (if-let [a 1] (inc a) :b)))