@@ -33,8 +33,8 @@ object Logger {
33
33
The ` Config ` object contains a definition of the ** inline value** ` logging ` .
34
34
This means that ` logging ` is treated as a _ constant value_ , equivalent to its
35
35
right-hand side ` false ` . The right-hand side of such an ` inline val ` must itself
36
- be a [ constant expression] ( https://scala-lang.org/files/archive/spec/2.12/06-expressions.html#constant-expressions ) . Used in this
37
- way, ` inline ` is equivalent to Java and Scala 2's ` final ` . Note that ` final ` , meaning
36
+ be a [ constant expression] ( https://scala-lang.org/files/archive/spec/2.12/06-expressions.html#constant-expressions ) .
37
+ Used in this way, ` inline ` is equivalent to Java and Scala 2's ` final ` . Note that ` final ` , meaning
38
38
_ inlined constant_ , is still supported in Dotty, but will be phased out.
39
39
40
40
The ` Logger ` object contains a definition of the ** inline method** ` log ` . This
@@ -272,8 +272,8 @@ The scrutinee `x` is examined statically and the inline match is reduced
272
272
accordingly returning the corresponding value (with the type specialized due to
273
273
the ` <: ` in the return type). This example performs a simple type test over the
274
274
scrutinee. The type can have a richer structure like the simple ADT below.
275
- ` toInt ` matches the structure of a number in Church-encoding and _ computes _ the
276
- corresponding integer.
275
+ ` toInt ` matches the structure of a number in [ Church-encoding] ( https://en.wikipedia.org/wiki/Church_encoding )
276
+ and _ computes _ the corresponding integer.
277
277
278
278
``` scala
279
279
trait Nat
@@ -319,11 +319,11 @@ the singleton type `2`.
319
319
320
320
#### ` erasedValue `
321
321
322
- We have seen so far inline methods that take terms (tuples and integers) as
322
+ So far we have seen inline methods that take terms (tuples and integers) as
323
323
parameters. What if we want to base case distinctions on types instead? For
324
324
instance, one would like to be able to write a function ` defaultValue ` , that,
325
- given a type ` T ` returns optionally the default value of ` T ` , if it exists. In
326
- fact, we can already express this using rewrite match expressions and a simple
325
+ given a type ` T ` , returns optionally the default value of ` T ` , if it exists.
326
+ We can already express this using rewrite match expressions and a simple
327
327
helper function, ` scala.compiletime.erasedValue ` , which is defined as follows:
328
328
329
329
``` scala
@@ -333,7 +333,7 @@ erased def erasedValue[T]: T = ???
333
333
The ` erasedValue ` function _ pretends_ to return a value of its type argument
334
334
` T ` . In fact, it would always raise a ` NotImplementedError ` exception when
335
335
called. But the function can in fact never be called, since it is declared
336
- ` erased ` , so can be only used at compile-time during type checking.
336
+ ` erased ` , so can only be used at compile-time during type checking.
337
337
338
338
Using ` erasedValue ` , we can then define ` defaultValue ` as follows:
339
339
@@ -360,10 +360,11 @@ Then:
360
360
val dAny : None .type = defaultValue[Any ]
361
361
```
362
362
363
- As another example, consider the type-level version of ` toNat ` above the we call
364
- ` toIntT ` : given a _ type_ representing a Peano number, return the integer _ value_
365
- corresponding to it. Consider the definitions of numbers as in the _ Inline
366
- Match_ section aboce. Here's how ` toIntT ` can be defined:
363
+ As another example, consider the type-level version of ` toInt ` below:
364
+ given a _ type_ representing a [ Peano number] ( https://wiki.haskell.org/Peano_numbers ) ,
365
+ return the integer _ value_ corresponding to it.
366
+ Consider the definitions of numbers as in the _ Inline
367
+ Match_ section above. Here is how ` toIntT ` can be defined:
367
368
368
369
``` scala
369
370
inline def toIntT [N <: Nat ] <: Int = inline scala.compiletime.erasedValue[N ] match {
0 commit comments