Merge pull request #241 from juhlig/master

bracket-push exercise in Erlang

config.json

@@ -244,6 +244,14 @@
         "mathematics"
       ]
     },
+    {
+      "slug": "bracket-push",
+      "uuid": "f93f5f18-3e3b-11e8-b467-0ed5f89f718b",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 3,
+      "topics": []
+    },
     {
       "slug": "gigasecond",
       "uuid": "24ae9a43-4e1c-418b-97f6-2c83dbc0e14a",

exercises/bracket-push/README.md

@@ -0,0 +1,45 @@
+Given a string containing brackets `[]`, braces `{}` and parentheses `()`,
+verify that all the pairs are matched and nested correctly.
+
+## Running tests
+
+In order to run the tests, issue the following command from the exercise
+directory:
+
+For running the tests provided, `rebar3` is used as it is the official build and
+dependency management tool for erlang now. Please refer to [the tracks installation
+instructions](http://exercism.io/languages/erlang/installation) on how to do that.
+
+In order to run the tests, you can issue the following command from the exercise
+directory.
+
+```bash
+$ rebar3 eunit
+```
+
+### Test versioning
+
+Each problem defines a macro `TEST_VERSION` in the test file and
+verifies that the solution defines and exports a function `test_version`
+returning that same value.
+
+To make tests pass, add the following to your solution:
+
+```erlang
+-export([test_version/0]).
+
+test_version() ->
+  1.
+```
+
+The benefit of this is that reviewers can see against which test version
+an iteration was written if, for example, a previously posted solution
+does not solve the current problem or passes current tests.
+
+## Questions?
+
+For detailed information about the Erlang track, please refer to the
+[help page](http://exercism.io/languages/erlang) on the Exercism site.
+This covers the basic information on setting up the development
+environment expected by the exercises.
+

exercises/bracket-push/rebar.config

@@ -0,0 +1,30 @@
+%% Erlang compiler options
+{erl_opts, [debug_info]}.
+
+{deps, [{erl_exercism, "0.1.1"}]}.
+
+{dialyzer, [
+  {warnings, [underspecs, no_return]},
+  {get_warnings, true},
+  {plt_apps, top_level_deps}, % top_level_deps | all_deps
+  {plt_extra_apps, []},
+  {plt_location, local}, % local | "/my/file/name"
+  {plt_prefix, "rebar3"},
+  {base_plt_apps, [stdlib, kernel, crypto]},
+  {base_plt_location, global}, % global | "/my/file/name"
+  {base_plt_prefix, "rebar3"}
+]}.
+
+%% eunit:test(Tests)
+{eunit_tests, []}.
+%% Options for eunit:test(Tests, Opts)
+{eunit_opts, [verbose]}.
+
+%% == xref ==
+
+{xref_warnings, true}.
+
+%% xref checks to run
+{xref_checks, [undefined_function_calls, undefined_functions,
+  locals_not_used, exports_not_used,
+  deprecated_function_calls, deprecated_functions]}.

exercises/bracket-push/src/bracket_push.app.src

@@ -0,0 +1,9 @@
+{application, bracket_push,
+  [{description, "exercism.io - bracket-push"},
+    {vsn, "0.0.1"},
+    {modules, []},
+    {registered, []},
+    {applications, [kernel,
+      stdlib]},
+    {env, []}
+]}.

exercises/bracket-push/src/bracket_push.erl

@@ -0,0 +1,7 @@
+-module(bracket_push).
+
+-export([is_paired/1, test_version/0]).
+
+is_paired(Str) -> undefined.
+
+test_version() -> 1.

exercises/bracket-push/src/example.erl

@@ -0,0 +1,15 @@
+-module(bracket_push).
+
+-export([is_paired/1, test_version/0]).
+
+is_paired(Str) -> is_paired(Str, []).
+
+is_paired([], Stack) -> Stack=:=[];
+is_paired([C|More], Stack) when C=:=${ orelse C=:=$[ orelse C=:=$( -> is_paired(More, [C|Stack]);
+is_paired([$}|More], [${|Stack]) -> is_paired(More, Stack);
+is_paired([$]|More], [$[|Stack]) -> is_paired(More, Stack);
+is_paired([$)|More], [$(|Stack]) -> is_paired(More, Stack);
+is_paired([C|_], _) when C=:=$} orelse C=:=$] orelse C=:=$)-> false;
+is_paired([_|More], Stack) -> is_paired(More, Stack).
+
+test_version() -> 1.

exercises/bracket-push/test/bracket_push_tests.erl

@@ -0,0 +1,55 @@
+% based on canonical data version 1.3.0
+% https://raw.githubusercontent.com/exercism/problem-specifications/master/exercises/bracket-push/canonical-data.json
+
+-module(bracket_push_tests).
+
+-include_lib("erl_exercism/include/exercism.hrl").
+-include_lib("eunit/include/eunit.hrl").
+
+paired_square_brackets_test() ->
+	?assert(bracket_push:is_paired("[]")).
+
+empty_string_test() ->
+	?assert(bracket_push:is_paired("")).
+
+unpaired_brackets_test() ->
+	?assertNot(bracket_push:is_paired("[[")).
+
+wrong_ordered_brackets_test() ->
+	?assertNot(bracket_push:is_paired("}{")).
+
+wrong_closing_bracket_test() ->
+	?assertNot(bracket_push:is_paired("{]")).
+
+paired_with_whitespace_test() ->
+	?assert(bracket_push:is_paired("{ }")).
+
+partially_paired_brackets_test() ->
+	?assertNot(bracket_push:is_paired("{[])")).
+
+simple_nested_brackets_test() ->
+	?assert(bracket_push:is_paired("{[]}")).
+
+several_paired_brackets_test() ->
+	?assert(bracket_push:is_paired("{}[]")).
+
+paired_and_nested_brackets_test() ->
+	?assert(bracket_push:is_paired("([{}({}[])])")).
+
+unopened_closing_brackets_test() ->
+	?assertNot(bracket_push:is_paired("{[)][]}")).
+
+unpaired_and_nested_brackets_test() ->
+	?assertNot(bracket_push:is_paired("([{])")).
+
+paired_and_wrong_nested_brackets_test()	->
+	?assertNot(bracket_push:is_paired("[({]})")).
+
+math_expression_test() ->
+	?assert(bracket_push:is_paired("(((185 + 223.85) * 15) - 543)/2")).
+
+complex_latex_expression_test()	->
+	?assert(bracket_push:is_paired("\\left(\\begin{array}{cc} \\frac{1}{3} & x\\\\ \\mathrm{e}^{x} &... x^2	\\end{array}\\right)")).
+
+version_test() -> ?assertMatch(1, bracket_push:test_version()).
+