feat: regular expr on exercise

internal/exercises/catalog.yaml

@@ -201,3 +201,13 @@ projects:
     - "Use Go's `time.Unix()` to convert an epoch to time."
     - "Use `t.Unix()` to convert time back to epoch."
     - "Remember Go’s `time.Parse` can help parse date strings."
+
+- slug: regular-expressions
+  title: Regular Expressions
+  test_regex: ".*"
+  hints:
+    - Use the regexp package from the standard library.
+    - Compile the pattern with regexp.Compile or regexp.MustCompile.
+    - Use MatchString on the compiled regex to check if the input matches the pattern.
+    - Patterns like ^a.*z$ match strings starting with 'a' and ending with 'z'.
+    - See https://pkg.go.dev/regexp for more examples.

internal/exercises/templates/regular-expressions/regular-expressions.go

@@ -0,0 +1,13 @@
+// regular-expressions.go
+// Exercise: Regular Expressions
+// Implement the function to match a string against a regular expression pattern.
+
+package templates
+
+import "regexp"
+
+// MatchRegex returns true if the input matches the pattern, false otherwise.
+func MatchRegex(pattern, input string) bool {
+	// TODO: implement this function
+	return false
+}

internal/exercises/templates/regular-expressions/regular-expressions_test.go

@@ -0,0 +1,26 @@
+package templates
+
+import "testing"
+
+func TestMatchRegex(t *testing.T) {
+	tests := []struct {
+		pattern string
+		input   string
+		want    bool
+	}{
+		{"^a.*z$", "abcz", true},
+		{"^a.*z$", "abz", true},
+		{"^a.*z$", "abc", false},
+		{"[0-9]+", "123", true},
+		{"[0-9]+", "abc", false},
+		{"hello|world", "hello", true},
+		{"hello|world", "world", true},
+		{"hello|world", "hi", false},
+	}
+	for _, tt := range tests {
+		got := MatchRegex(tt.pattern, tt.input)
+		if got != tt.want {
+			t.Errorf("MatchRegex(%q, %q) = %v; want %v", tt.pattern, tt.input, got, tt.want)
+		}
+	}
+}