Use a terser style on slides. Avoid footnotes

src/idiomatic/leveraging-the-type-system.md

@@ -4,15 +4,15 @@ minutes: 5
 
 # Leveraging the Type System
 
-Rust's type system is _expressive_.\
+Rust's type system is _expressive_: you can use types and traits to build
-We can use types and traits to build abstractions that make our code harder to
+abstractions that make your code harder to misuse.
-misuse. In some cases, we can even go as far as enforcing correctness at
-_compile-time_. Quite often, these abstractions have no runtime
-overhead[^zero-cost].
 
-The type system can also be used to model concepts and constraints from your
+In some cases, you can go as far as enforcing correctness at _compile-time_,
-business domain. By designing our types carefully, we can improve the clarity
+with no runtime overhead.
-and maintainability of the entire codebase.
+
+Types and traits can model concepts and constraints from your business domain.
+With careful design, you can improve the clarity and maintainability of the
+entire codebase.
 
 <details>
 
@@ -36,12 +36,12 @@ Additional items speaker may mention:
   doesn't support inheritance, and object boundaries must be mindful of the
   constraints introduced by the borrow-checker.
 
+- Mention that type-level abstractions are often referred to as "zero-cost
+  abstractions", although the label can be misleading: the impact on compile
+  times and code complexity may be significant.
+
 </details>
 
 {{%segment outline}}
 
 [1]: https://pragprog.com/titles/swdddf/domain-modeling-made-functional/
-
-[^zero-cost]: They often referred to as "zero-cost abstractions", although the
-    label can be misleading: the impact on compile times and code complexity may
-    be significant.

src/idiomatic/leveraging-the-type-system/newtype-pattern/parse-don-t-validate.md

@@ -36,27 +36,26 @@ impl Username {
 - The newtype pattern, combined with Rust's module and visibility system, can be
   used to _guarantee_ that instances of a given type satisfy a set of
   invariants.\
-  In the example above, the raw `String` stored inside the
+  In the example above, the raw `String` stored inside the `Username` struct
-  `Username` struct can't be accessed directly from other modules or crates,
+  can't be accessed directly from other modules or crates, since it's not marked
-  since it's not marked as `pub` or `pub(in ...)`. Consumers of the `Username`
+  as `pub` or `pub(in ...)`. Consumers of the `Username` type are forced to use
-  type are forced to use the `new` method to create instances. In turn, `new`
+  the `new` method to create instances. In turn, `new` performs validation, thus
-  performs validation, thus ensuring that all instances of `Username` satisfy
+  ensuring that all instances of `Username` satisfy those checks.
-  those checks.
 
 - The `as_str` method allows consumers to access the raw string representation
-  (e.g. to store it in a database) but, thanks to Rust's borrow checker,
+  (e.g. to store it in a database) but, thanks to Rust's borrow checker, they
-  they can't modify it.
+  can't modify it.
 
-- Stress the importance of evaluating _the entire API surface_ exposed by a newtype
+- Stress the importance of evaluating _the entire API surface_ exposed by a
-  to determine if invariants are indeed bullet-proof.\
+  newtype to determine if invariants are indeed bullet-proof.\
-  It is crucial to consider all possible interactions, including trait implementations,
+  It is crucial to consider all possible interactions, including trait
-  that may allow users to bypass the invariants. For example, if the `Username`
+  implementations, that may allow users to bypass the invariants. For example,
-  type implements the `DerefMut` trait, users can modify the underlying string
+  if the `Username` type implements the `DerefMut` trait, users can modify the
-  directly, bypassing the validation checks in `new`.
+  underlying string directly, bypassing the validation checks in `new`.
 
 - Type-level invariants have second-order benefits.\
-  The input is validated once, at the boundary, and the rest of the program can rely
+  The input is validated once, at the boundary, and the rest of the program can
-  on the invariants being upheld. We can avoid redundant validation and
+  rely on the invariants being upheld. We can avoid redundant validation and
   "defensive programming" checks throughout the program, reducing noise and
   improving performance.