adjust links

Author: bishabosha

_overviews/scala3-contribution/arch-lifecycle.md

@@ -7,48 +7,48 @@ previous-page: arch-intro
 next-page: arch-phases
 ---
 
-As mentioned in [what is a compiler?][1] `dotc` produces programs that can run on your machine,
+As mentioned in [what is a compiler?][whats-a-compiler] `dotc` produces programs that can run on your machine,
 first by verifying its input is a valid Scala program, and then transforming it into a
 representation that can run on one of Scala's target platforms.
 
 ## Introducing the Compiler's Lifecycle
 
 #### Core
-At a high level, `dotc` centers its work around a [Compiler][4], which maintains an ordered
-list of [phases][3], and is responsible for creating new [runs][2].
+At a high level, `dotc` centers its work around a [Compiler], which maintains an ordered
+list of [phases][Phases], and is responsible for creating new [runs][Run].
 A run is a complete iteration of the compiler's phases over a list of input sources.
 A compiler is designed to be reusable and can create many runs over its lifetime.
 
 #### Runs
-During a run, the input sources are converted to [compilation units][5] (i.e. the abstraction of
+During a run, the input sources are converted to [compilation units][CompilationUnit] (i.e. the abstraction of
 compiler state associated with each input source); then iteratively: a single phase is applied to
 every compilation unit before progressing to the next phase.
 
 #### Phases
 A phase is an abstract transformation over a compilation unit, it is usually responsible
 for transforming the trees and types representing the code of a source file. Some phases of
-the compiler include
+the compiler include:
 - `parser`, which converts text that matches Scala's
-  [syntax][10] into abstract syntax trees, ASTs
+  [syntax] into abstract syntax trees, ASTs
 - `typer`, which checks that trees conform to expected types
 - `erasure`, which retypes a more simplified program into one that has the same types as the JVM.
 - `genBCode`, the JVM backend, which converts erased compiler trees into Java bytecode format.
 
-[You can read more about phases here][9].
+[You can read more about phases here][phase-categories].
 
 #### Drivers
 
-The core compiler also requires a lot of state to be initialised before use, such as [settings][8]
-and the [Context]. For convenience, the [Driver] class contains high level functions for
+The core compiler also requires a lot of state to be initialised before use, such as [settings][ScalaSettings]
+and the [Context][contexts]. For convenience, the [Driver] class contains high level functions for
 configuring the compiler and invoking it programatically. The object [Main] inherits from `Driver`
 and is invoked by the `scalac` script.
 
 <!-- #### Further Reading -->
-> [Read more about a compiler's lifecyle][6].
+> [Read more about a compiler's lifecyle][time].
 
 ## Code Structure
 
-The code of the compiler is found in the package [dotty.tools][7],
+The code of the compiler is found in the package [dotty.tools],
 containing the following sub-packages:
 ```scala
 tools // contains helpers and the `scala` generic runner
@@ -82,18 +82,16 @@ tools // contains helpers and the `scala` generic runner
 └── scripting // scala runner for the -script argument
 ```
 
-[1]: {% link _overviews/scala3-contribution/contribution-intro.md %}#what-is-a-compiler
-[2]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/Run.scala
-[3]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/core/Phases.scala
-[4]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/Compiler.scala
-[5]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/CompilationUnit.scala
-[6]: {% link _overviews/scala3-contribution/arch-time.md %}
-[7]: https://github.com/lampepfl/dotty/tree/master/compiler/src/dotty/tools
-[8]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/config/ScalaSettings.scala
-[9]: {% link _overviews/scala3-contribution/arch-phases.md %}
-[10]: {% link _scala3-reference/syntax.md %}
+[whats-a-compiler]: {% link _overviews/scala3-contribution/contribution-intro.md %}#what-is-a-compiler
+[Phases]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/core/Phases.scala
+[CompilationUnit]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/CompilationUnit.scala
+[time]: {% link _overviews/scala3-contribution/arch-time.md %}
+[dotty.tools]: https://github.com/lampepfl/dotty/tree/master/compiler/src/dotty/tools
+[ScalaSettings]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/config/ScalaSettings.scala
+[phase-categories]: {% link _overviews/scala3-contribution/arch-phases.md %}#phase-categories
+[syntax]: {% link _scala3-reference/syntax.md %}
 [Main]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/Main.scala
 [Driver]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/Driver.scala
 [Compiler]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/Compiler.scala
 [Run]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/Run.scala
-[Context]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/core/Contexts.scala
+[contexts]: {% link _overviews/scala3-contribution/arch-context.md %}

_overviews/scala3-contribution/arch-phases.md

@@ -7,7 +7,7 @@ previous-page: arch-lifecycle
 next-page: arch-types
 ---
 
-As described in the [compiler overview][1], `dotc` is divided into a list of [phases][Phase],
+As described in the [compiler overview][lifecycle], `dotc` is divided into a list of [phases][Phase],
 specified in the [Compiler] class.
 
 #### Printing the phases of the Compiler
@@ -52,7 +52,7 @@ In particular, it
 - creates super accessors representing `super` calls in traits
 - creates implementations of compiler-implemented methods,
 such as `equals` and `hashCode` for case classes.
-- marks [compilation units][2] that require inline expansion, or quote pickling
+- marks [compilation units][CompilationUnit] that require inline expansion, or quote pickling
 - simplifies trees of erased definitions
 - checks variance of type parameters
 - mark parameters passed unchanged from subclass to superclass for later pruning.
@@ -72,6 +72,9 @@ suitable for the runtime system, with two sub-groupings:
 - High-level transformations: All phases from [firstTransform] to [erasure].
   Most of these phases transform syntax trees, expanding high-level constructs
   to more primitive ones.
+  - An important transform phase is [patternMatcher], which converts match
+    trees and patterns into lower level forms, as well as checking the
+    exhaustivity of sealed types, and unreachability of pattern cases.
   - Some phases perform further checks on more primitive trees,
     e.g. [refchecks] verifies that no abstract methods exist in concrete classes,
     and [initChecker] checks that fields are not used before initialisation.
@@ -86,8 +89,8 @@ suitable for the runtime system, with two sub-groupings:
 ### `backendPhases`
 These map the transformed trees to Java classfiles or SJSIR files.
 
-[1]: {% link _overviews/scala3-contribution/arch-lifecycle.md %}#phases
-[2]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/CompilationUnit.scala
+[lifecycle]: {% link _overviews/scala3-contribution/arch-lifecycle.md %}#phases
+[CompilationUnit]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/CompilationUnit.scala
 [Compiler]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/Compiler.scala
 [Phase]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/core/Phases.scala
 [MiniPhase]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/transform/MegaPhase.scala
@@ -104,6 +107,7 @@ These map the transformed trees to Java classfiles or SJSIR files.
 [refchecks]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
 [initChecker]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/transform/init/Checker.scala
 [firstTransform]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/transform/FirstTransform.scala
+[patternMatcher]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala
 [erasure]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/transform/Erasure.scala
 [Mirror]: https://github.com/lampepfl/dotty/blob/master/library/src/scala/deriving/Mirror.scala
 [PCP]: {% link _scala3-reference/metaprogramming/macros.md %}#the-phase-consistency-principle

_overviews/scala3-contribution/arch-types.md

@@ -14,8 +14,8 @@ defined in [Types.scala]. The `toString` method on `Type` will display types in
 format corresponding to the backing data structure, e.g. `ExprType(...)`
 corresponds to `class ExprType`, defined in [Types.scala].
 
-> You can inspect the representation of any type using the [dotty.tools.printTypes][2]
-> script, its usage and integration into your debugging workflow is [described here][3].
+> You can inspect the representation of any type using the [dotty.tools.printTypes][DottyTypeStealer]
+> script, its usage and integration into your debugging workflow is [described here][inspecting-types].
 
 ### Types of Definitions
 
@@ -148,5 +148,5 @@ Type -+- proxy_type --+- NamedType --------+- TypeRef
 ```
 
 [Types.scala]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/core/Types.scala
-[2]: https://github.com/lampepfl/dotty/blob/master/compiler/test/dotty/tools/DottyTypeStealer.scala
-[3]: {% link _overviews/scala3-contribution/procedures-inspection.md %}#inspecting-representation-of-types
+[DottyTypeStealer]: https://github.com/lampepfl/dotty/blob/master/compiler/test/dotty/tools/DottyTypeStealer.scala
+[inspecting-types]: {% link _overviews/scala3-contribution/procedures-inspection.md %}#inspecting-the-representation-of-types

_overviews/scala3-contribution/procedures-inspection.md

@@ -98,10 +98,10 @@ and so on.
 
 ## Inspecting The Representation of Types
 
-> [click here][2] to learn more about types in `dotc`.
+> [learn more about types][types] in `dotc`.
 
 If you are curious about the representation of a type, say `[T] =>> List[T]`,
-you can use a helper program [dotty.tools.printTypes][1],
+you can use a helper program [dotty.tools.printTypes][DottyTypeStealer],
 it prints the internal representation of types, along with their class. It can be
 invoked from the sbt shell with three arguments as follows:
 ```bash
@@ -178,9 +178,8 @@ class StealBox:
         assert(empty.name.toString == "<empty>")
 ```
 
-[1]: https://github.com/lampepfl/dotty/blob/master/compiler/test/dotty/tools/DottyTypeStealer.scala
-[2]: {% link _overviews/scala3-contribution/arch-types.md %}
-[3]: {% link _overviews/scala3-contribution/arch-lifecycle.md %}#phases
+[DottyTypeStealer]: https://github.com/lampepfl/dotty/blob/master/compiler/test/dotty/tools/DottyTypeStealer.scala
+[types]: {% link _overviews/scala3-contribution/arch-types.md %}
 [ScalaSettings]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/config/ScalaSettings.scala
 [symbols]: https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
 [reproduce]: {% link _overviews/scala3-contribution/procedures-reproduce.md %}#dotty-issue-workspace