From 6efbc4b1205afa81c4bf626733b8823bb871871d Mon Sep 17 00:00:00 2001
From: Bruce Hill <bruce@bruce-hill.com>
Date: Mon, 24 Mar 2025 18:06:22 -0400
Subject: [PATCH] More lessons

---
 koans.tm                                |  6 ++++--
 lesson-templates/lesson-02-tests.tm     | 26 ++++++++++++++++++++++++
 lesson-templates/lesson-02.tm           | 22 --------------------
 lesson-templates/lesson-03-variables.tm | 27 +++++++++++++++++++++++++
 lesson-templates/lesson-04-functions.tm | 26 ++++++++++++++++++++++++
 5 files changed, 83 insertions(+), 24 deletions(-)
 create mode 100644 lesson-templates/lesson-02-tests.tm
 delete mode 100644 lesson-templates/lesson-02.tm
 create mode 100644 lesson-templates/lesson-03-variables.tm
 create mode 100644 lesson-templates/lesson-04-functions.tm

diff --git a/koans.tm b/koans.tm
index 8ef7a8b..a52e014 100644
--- a/koans.tm
+++ b/koans.tm
@@ -13,7 +13,7 @@ enum TestResult(Success(output:Text), Error(err:Text), WrongOutput(actual:Text,
         when result is Success(s):
             $Colorful"
                 @(b,u:Program Output:)
-                $s
+                @(green:$s)
             ":print()
         is Error(e):
             $Colorful"
@@ -48,7 +48,9 @@ struct Lesson(file:Path, description:Text, expected_output=none:Text):
 
 LESSONS := [
     Lesson((./lessons/lesson-01-hello-world.tm), "Hello World", "Hello world$\n"),
-    Lesson((./lessons/lesson-02.tm), "Working with Text"),
+    Lesson((./lessons/lesson-02-tests.tm), "Testing Code"),
+    Lesson((./lessons/lesson-03-variables.tm), "Variables"),
+    Lesson((./lessons/lesson-04-functions.tm), "Functions"),
 ]
 
 func ask_continue():
diff --git a/lesson-templates/lesson-02-tests.tm b/lesson-templates/lesson-02-tests.tm
new file mode 100644
index 0000000..44de43e
--- /dev/null
+++ b/lesson-templates/lesson-02-tests.tm
@@ -0,0 +1,26 @@
+# Docstring Tests
+
+func main():
+    # Docstring tests begin with `>>` and can
+    # be used to check that a value is what you
+    # expected it to be:
+
+    >> 1 + 1
+    = 2
+
+    # If you don't provide an expected value,
+    # the expression will just be printed out
+    # and not checked:
+    >> 2 + 3
+
+    # If a docstring test's output is different
+    # from what was expected, it will print an
+    # error message and halt the program.
+
+    # Edit this test so it passes:
+    >> 2 + 2
+    = 9999
+
+    # For the rest of this tutorial, you won't
+    # be editing any of the tests, you'll be
+    # fixing code so it passes the tests.
diff --git a/lesson-templates/lesson-02.tm b/lesson-templates/lesson-02.tm
deleted file mode 100644
index 205bdd5..0000000
--- a/lesson-templates/lesson-02.tm
+++ /dev/null
@@ -1,22 +0,0 @@
-func main():
-    say("
-        Let's learn about text concatenation!
-        It uses the `++` operator:
-    ")
-
-    greeting := "Hello "
-
-    ##############################################################
-    ###################### EDIT BELOW HERE #######################
-    ##############################################################
-
-    your_text := greeting ++ "space"
-
-    ##############################################################
-    ################## DO NOT EDIT AFTER HERE ####################
-    ##############################################################
-
-    say(your_text)
-
-    >> your_text
-    = "Hello world"
diff --git a/lesson-templates/lesson-03-variables.tm b/lesson-templates/lesson-03-variables.tm
new file mode 100644
index 0000000..01685f5
--- /dev/null
+++ b/lesson-templates/lesson-03-variables.tm
@@ -0,0 +1,27 @@
+# Variables
+
+func main():
+
+    # Variable declarations use `:=` and do not
+    # require you to specify a type explicitly:
+    x := 123
+
+    # To assign a new value, use `=`
+    x = 999
+
+    # You can also use update assignments like `+=`
+    x += 1
+
+    >> x
+    = 1000
+
+    # Variables are strongly typed, so you can't
+    # assign different types to the same variable:
+    x = "hello"
+
+    # Declare a variable called `y` and give it the
+    # value "okay"
+
+
+    >> y
+    = "okay"
diff --git a/lesson-templates/lesson-04-functions.tm b/lesson-templates/lesson-04-functions.tm
new file mode 100644
index 0000000..83d3b9e
--- /dev/null
+++ b/lesson-templates/lesson-04-functions.tm
@@ -0,0 +1,26 @@
+# Functions
+
+func main():
+
+    # Functions can be declared in any order.
+    # The main() function is the first function to run,
+    # but it can call any other functions defined in
+    # the same file.
+
+    # Here, we're calling a function defined below.
+    # Fix up the function so it passes thes tests:
+    >> add(5, 10)
+    = 15
+    >> add(2, 4)
+    = 6
+
+    # Functions can also be called with keyword arguments:
+    >> add(x=4, y=12)
+    = 16
+
+# Functions are defined using `func` and must specify
+# the types of their arguments and return values like this:
+func add(x:Int, y:Int -> Int):
+
+    # Fix this so it returns a sensible result:
+    return 0