From d30c9704a6d7c2aec01d3e65d5185506f328cea7 Mon Sep 17 00:00:00 2001
From: alexchao26 <alexchaoo@gmail.com>
Date: Mon, 21 Dec 2020 19:46:50 -0500
Subject: [PATCH] casting package started, this feels strange in Go...

---
 cast/cast.go      | 74 +++++++++++++++++++++++++++++++++++++
 cast/cast_test.go | 94 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 168 insertions(+)
 create mode 100644 cast/cast.go
 create mode 100644 cast/cast_test.go

diff --git a/cast/cast.go b/cast/cast.go
new file mode 100644
index 0000000..324e0fa
--- /dev/null
+++ b/cast/cast.go
@@ -0,0 +1,74 @@
+package cast
+
+// Suite of casting functions to speed up solutions
+// This is NOT idiomatic Go... but AOC isn't about that...
+
+import "strconv"
+
+// ToInt will case a given arg into an int type.
+// Supported types are:
+//    - string
+func ToInt(arg interface{}) int {
+	var val int
+	switch arg.(type) {
+	case string:
+		var err error
+		val, err = strconv.Atoi(arg.(string))
+		if err != nil {
+			panic("error converting string to int " + err.Error())
+		}
+	default:
+		panic("unhandled type for int casting")
+	}
+	return val
+}
+
+// ToString will case a given arg into an int type.
+// Supported types are:
+//    - int
+//    - byte
+//    - rune
+func ToString(arg interface{}) string {
+	var str string
+	switch arg.(type) {
+	case int:
+		str = strconv.Itoa(arg.(int))
+	case byte:
+		b := arg.(byte)
+		str = string(rune(b))
+	case rune:
+		str = string(arg.(rune))
+	default:
+		panic("unhandled type for string casting")
+	}
+	return str
+}
+
+const (
+	ASCIICodeCapA   = int('A') // 65
+	ASCIICodeLowerA = int('a') // 97
+)
+
+// ToASCIICode returns the ascii code of a given input
+func ToASCIICode(arg interface{}) int {
+	var asciiVal int
+	switch arg.(type) {
+	case string:
+		str := arg.(string)
+		if len(str) != 1 {
+			panic("can only convert ascii Code for string of length 1")
+		}
+		asciiVal = int(str[0])
+	case byte:
+		asciiVal = int(arg.(byte))
+	case rune:
+		asciiVal = int(arg.(rune))
+	}
+
+	return asciiVal
+}
+
+// ASCIIIntToChar returns a one character string of the given int
+func ASCIIIntToChar(code int) string {
+	return string(rune(code))
+}
diff --git a/cast/cast_test.go b/cast/cast_test.go
new file mode 100644
index 0000000..5028fb1
--- /dev/null
+++ b/cast/cast_test.go
@@ -0,0 +1,94 @@
+package cast_test
+
+import (
+	"testing"
+
+	"github.com/alexchao26/advent-of-code-go/cast"
+)
+
+func TestToInt(t *testing.T) {
+	if got := cast.ToInt("123"); got != 123 {
+		t.Errorf("cast.Int(123) = %v, want 123", got)
+	}
+	if got := cast.ToInt("9835"); got != 9835 {
+		t.Errorf("cast.Int(9835) = %v, want 9835", got)
+	}
+}
+
+func TestToString(t *testing.T) {
+	byteTests := []struct {
+		name  string
+		input interface{}
+		want  string
+	}{
+		{"byte", byte('a'), "a"},
+		{"byte", byte('x'), "x"},
+		{"int", 1234, "1234"},
+		{"int", 512, "512"},
+		{"rune", rune(65), "A"},
+		{"rune", rune(97), "a"},
+	}
+	for _, tt := range byteTests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := cast.ToString(tt.input); got != tt.want {
+				t.Errorf("ToString(byte) = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestToASCIIConstants(t *testing.T) {
+	if cast.ASCIICodeCapA != 65 {
+		t.Errorf("Expected cast.ASCIICodeCapA to be 65, got %d", cast.ASCIICodeCapA)
+	}
+	if cast.ASCIICodeLowerA != 97 {
+		t.Errorf("Expected cast.ASCIICodeLowerA to be 97, got %d", cast.ASCIICodeLowerA)
+	}
+}
+
+func TestToASCIICode(t *testing.T) {
+	type args struct {
+		arg interface{}
+	}
+	tests := []struct {
+		name string
+		args args
+		want int
+	}{
+		{"example_string", args{"a"}, cast.ASCIICodeLowerA},
+		{"example_string", args{"b"}, cast.ASCIICodeLowerA + 1},
+		{"example_string", args{"z"}, cast.ASCIICodeLowerA + 25},
+		{"example_string", args{"C"}, cast.ASCIICodeCapA + 2},
+		{"example_rune", args{rune(97)}, 97},
+		{"example_byte", args{'a'}, 97},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := cast.ToASCIICode(tt.args.arg); got != tt.want {
+				t.Errorf("ToASCIICode() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestASCIIIntToChar(t *testing.T) {
+	type args struct {
+		code int
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{"example", args{97}, "a"},
+		{"example", args{98}, "b"},
+		{"example", args{65}, "A"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := cast.ASCIIIntToChar(tt.args.code); got != tt.want {
+				t.Errorf("ASCIIIntToChar() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}