From da705aafa5a1890f640c06176bd7576dcdc60b05 Mon Sep 17 00:00:00 2001
From: Jonata Weber <jonataa@gmail.com>
Date: Thu, 25 Oct 2018 11:57:52 -0200
Subject: [PATCH 1/3] implement find first recurrence function

---
 .../jonataweber/FirstRecurrence.php           | 31 +++++++++++++++++++
 .../jonataweber/FirstRecurrenceTest.php       | 10 ++++++
 2 files changed, 41 insertions(+)
 create mode 100644 src/primeira_recorrencia/jonataweber/FirstRecurrence.php
 create mode 100644 src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php

diff --git a/src/primeira_recorrencia/jonataweber/FirstRecurrence.php b/src/primeira_recorrencia/jonataweber/FirstRecurrence.php
new file mode 100644
index 0000000..7e75479
--- /dev/null
+++ b/src/primeira_recorrencia/jonataweber/FirstRecurrence.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Evolua\Recurrence;
+
+/**
+ * Find the first recurrence in the text.
+ * 
+ * in: 'ABCDA' out: 'A'
+ * in: 'ABBCDA' out: 'B'
+ * in: 'ABBCDDA' out: 'B'
+ * in: 'ABC' out: null
+ *
+ * @param string $haystack
+ * @param integer $offset
+ * @param Array $carry
+ * @return (string | null)
+ */
+function first(string $haystack, int $offset = 0, Array $carry = [])
+{
+    $char = $haystack[$offset];
+    $carry[$char] = ($carry[$char] ?? 0) + 1;
+
+    $isLastCharacter = $offset >= (strlen($haystack) - 1);
+    $isRecurrence = $carry[$char] > 1;
+    $notFoundRecurrence = $isLastCharacter && false === $isRecurrence;
+
+    if ($notFoundRecurrence) return null;
+    if ($isLastCharacter || $isRecurrence) return $char;
+
+    return first($haystack, $offset + 1, $carry);
+}
\ No newline at end of file
diff --git a/src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php b/src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php
new file mode 100644
index 0000000..ee4462d
--- /dev/null
+++ b/src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php
@@ -0,0 +1,10 @@
+<?php
+
+require_once __DIR__ . '/FirstRecurrence.php';
+
+use function Evolua\Recurrence\first;
+
+assert(first('ABCDA') === 'A');
+assert(first('ABBCDA') === 'B');
+assert(first('ABBCDDA') === 'B');
+assert(first('ABC') === null);
\ No newline at end of file

From 3934a923c040703976b988831c432303be5095cb Mon Sep 17 00:00:00 2001
From: Jonata Weber <jonataa@gmail.com>
Date: Thu, 25 Oct 2018 12:04:43 -0200
Subject: [PATCH 2/3] add end of line

---
 src/primeira_recorrencia/jonataweber/FirstRecurrence.php     | 2 +-
 src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/primeira_recorrencia/jonataweber/FirstRecurrence.php b/src/primeira_recorrencia/jonataweber/FirstRecurrence.php
index 7e75479..862c1f3 100644
--- a/src/primeira_recorrencia/jonataweber/FirstRecurrence.php
+++ b/src/primeira_recorrencia/jonataweber/FirstRecurrence.php
@@ -28,4 +28,4 @@ function first(string $haystack, int $offset = 0, Array $carry = [])
     if ($isLastCharacter || $isRecurrence) return $char;
 
     return first($haystack, $offset + 1, $carry);
-}
\ No newline at end of file
+}
diff --git a/src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php b/src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php
index ee4462d..9d4f4c0 100644
--- a/src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php
+++ b/src/primeira_recorrencia/jonataweber/FirstRecurrenceTest.php
@@ -7,4 +7,4 @@
 assert(first('ABCDA') === 'A');
 assert(first('ABBCDA') === 'B');
 assert(first('ABBCDDA') === 'B');
-assert(first('ABC') === null);
\ No newline at end of file
+assert(first('ABC') === null);

From 4597893f052cc95ebb1df04712d5aa49aa3b1e58 Mon Sep 17 00:00:00 2001
From: Jonata Weber <jonataa@gmail.com>
Date: Thu, 25 Oct 2018 19:07:52 -0200
Subject: [PATCH 3/3] bit of refactorig

---
 src/primeira_recorrencia/jonataweber/FirstRecurrence.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/primeira_recorrencia/jonataweber/FirstRecurrence.php b/src/primeira_recorrencia/jonataweber/FirstRecurrence.php
index 862c1f3..b43d663 100644
--- a/src/primeira_recorrencia/jonataweber/FirstRecurrence.php
+++ b/src/primeira_recorrencia/jonataweber/FirstRecurrence.php
@@ -24,8 +24,8 @@ function first(string $haystack, int $offset = 0, Array $carry = [])
     $isRecurrence = $carry[$char] > 1;
     $notFoundRecurrence = $isLastCharacter && false === $isRecurrence;
 
+    if ($isRecurrence) return $char;
     if ($notFoundRecurrence) return null;
-    if ($isLastCharacter || $isRecurrence) return $char;
 
     return first($haystack, $offset + 1, $carry);
 }