Learn Norm

Each lesson introduces one feature through a runnable program, its checked output, an explanation, and one change to try. Follow the order for a gradual start, or open a specific topic.

The full learning path is checked against the development toolchain. Use Status and the version index to check the capabilities of an installed release.

Write and run a program

Lesson	New feature
01 Program entry	Start a single-file program with main()
02 Explicit types and assignment	Declare and update typed variables
03 Type inference	Let an initializer determine a local type
04 String interpolation	Place expressions inside strings
05 Operators and comparisons	Compute numbers and Boolean results
06 Conditional execution	Choose a block with if/else

Organize calculations with functions

Lesson	New feature
07 Functions and explicit returns	Name a calculation and return its result
08 Named arguments	Bind call values to parameter labels
09 Default arguments	Omit an argument with a declared default
10 Argument shorthand	Reuse matching local and parameter names
11 if as a result	Return a value from either branch
12 Final-expression returns	Use the last expression as a function result

Work with collections and control flow

Lesson	New feature
13 Lists	A list stores an ordered sequence whose length can change.
14 Iteration	Use for to visit each element without managing an index yourself.
15 Conditional loops	A condition-style for repeats while its Boolean condition remains true.
16 Break	A valueless break leaves the current statement loop immediately.
17 Continue	continue skips the rest of one iteration and proceeds to the next.
18 Arrays	An array is indexed like a list but keeps a fixed length.
19 Maps	A map associates a typed key with a typed value.
20 Sets	A set keeps distinct elements and answers membership queries.
21 Collection value semantics	Assigning a built-in collection gives the new binding an independent container value.
22 Collection for elements	A collection literal can generate elements from another iterable.
23 Collection if elements	A collection literal can include an element only when a condition holds.
24 Spread in collections	... inserts the elements of an iterable at one position in a collection literal.

Model values and entities

Lesson	New feature
25 Value declarations	A value groups immutable fields into a typed data value.
26 Value equality	Values compare by their contents rather than by creation event.
27 Class declarations	A class models an entity with fields and behavior that can change.
28 Class identity	Class variables can refer to the same entity or to distinct entities with equal-looking fields.
29 Copying a class	Call copy() when a new top-level class identity is needed.
30 Explicit constructors	A class can replace implicit field construction with a same-named constructor.
31 Computed properties	A computed property presents accessor behavior with field-like syntax.
32 Fluent methods	A method may return this so the caller can continue operating on the same object.

Handle absence and match states

Lesson	New feature
33 Nullable values	A ? on a type permits null; the type without ? does not.
34 Flow narrowing	A null check can prove a nullable value non-null inside a branch.
35 Safe access	?. reads a member only when its receiver exists.
36 Null fallback	?? uses its right operand only when the left operand is null.
37 Plain enums	An enum lists a finite set of named alternatives.
38 Data enums	Enum alternatives may carry differently typed data.
39 Switch results	switch can produce a result while extracting an enum variant's payload.
40 Exhaustive matching	A switch over a closed enum must account for every variant.
41 Nested patterns	A pattern may match a variant inside another variant's payload.

Compose abstractions

Lesson	New feature
42 Interface declarations	Specify a callable contract.
43 Implementing an interface	Provide the required behavior.
44 Default interface methods	Share behavior in the contract.
45 Class inheritance	Extend a class and initialize its base.
46 Overriding methods	Dispatch to a subclass implementation.
47 Generic types	Parameterize a data type.
48 Generic functions	Parameterize a calculation.
49 Generic inference	Infer type arguments from call values.
50 Matching generic types	Distinguish generic instantiations at runtime.
51 Function overloads	Select a signature by argument type.

Functions as values

Lesson	New feature
52 Function values	Store and pass callable values.
53 Lambdas	Create a function value at its use site.
54 Capturing values	Keep access to an enclosing value.
55 Bound method references	Bind a callable to an object.
56 Extension functions	Call a static function through receiver syntax.
57 Trailing callbacks	Supply a final callback as a block.
58 Named callback parameters	Name a callback's supplied value.
59 Chaining block calls	Compose functions with trailing blocks.

Build a project

Lesson	New feature
60 Imports	Use a public declaration from another package.
61 Modules	Describe a module's name, version, and exports.
62 Packages	Give source files structured names.
63 Visibility	Separate public API from file-private details.
64 Local dependencies	Consume a packaged library through the module graph.
65 Tests	Declare and run a test.
66 Exception handling	Catch exceptional control flow.
67 Cleanup with finally	Run cleanup on every exit.

Describe declarations

Lesson	New feature
68 Type declaration references	Read type metadata through a checked declaration.
69 Field declaration references	Read and write a field through its descriptor.
70 Function declaration references	Use a checked callable declaration reference.
71 Annotation targets	Restrict where an annotation may appear.
72 Annotation retention	Choose how long annotation data remains available.
73 Runtime annotation metadata	Read a runtime-retained annotation.
74 Function interception	Wrap a function call with around.
75 Interceptor entry and exit	Observe before, body, and after order.
76 Documenting declarations for agents	Expose checked intent through @Document and query.

Observe and build

Lesson	New feature
77 Lexical references	Borrow a writable local location.
78 Field handles	Bind a field descriptor to an object.
79 Field subscriptions	Watch assignments and close a subscription.
80 Collection change notifications	Watch collection mutations through a field.
81 Resource ownership	Register and release owned subscriptions.
82 Result builders	Accumulate expressions into a result.
83 Control flow in result builders	Accumulate selected branches and loop iterations.

Use libraries

Lesson	New feature
84 JSON value roundtrip	Encode and decode a checked value.
85 Writing and reading a file	Claim a new file and read it back.
86 Typed file failures	Handle a missing file by failure category.
87 A packaged library	Consume an external library through a direct dependency.

For a complete GUI Todo and Web guestbook, use the generated norm hello programs with the development toolchain.

The Language Reference defines precise rules; Status describes released capabilities.

Start with Program entry.