Adds interpolated string (#23)

* Adds interpolated string POC

* Add example and README docs

* Added anonymous record test

* Added doccomment to setMessageInterpolated and formatted code

* Adds more info about interpolated strings to README

* Update README

Author: TheAngryByrd

README.md

@@ -1,9 +1,16 @@
 # FsLibLog
 
-FsLibLog is a single file you can copy paste or add through [Paket Github dependencies](https://fsprojects.github.io/Paket/github-dependencies.html) to provide your F# library with a logging abstraction.  This is a port of the C# [LibLog](https://github.com/damianh/LibLog).
+## What is this?
 
+FsLibLog is a single file you can copy paste or add through [Paket Github dependencies](https://fsprojects.github.io/Paket/github-dependencies.html) to provide your F# library with a logging abstraction. This is a port of the C# [LibLog](https://github.com/damianh/LibLog).
 
-## Getting started
+## Why does this exist?
+
+When creating a library for .NET, you typically do not want to depend on a logging framework or abstraction. Depending on a logging framework forces your consumers to use that framework, which is not ideal. Depending on an abstraction _can_ work but you can run into the [diamond dependency](https://docs.microsoft.com/en-us/dotnet/standard/library-guidance/dependencies#diamond-dependencies) problem. Since this is just a file you compile into your library, no dependency is taken and is transparent to your consumers.
+
+Additionally, loggers aren't particularly friendly for F#, this sets out to resolve that.
+
+## How to get started
 
 ### 1. Put the file into your project
 
@@ -17,17 +24,16 @@ Read over [Paket Github dependencies](https://fsprojects.github.io/Paket/github-
 
 Add the following line to your `paket.depedencies` file.
 
-```
+```paket
 github TheAngryByrd/FsLibLog src/FsLibLog/FsLibLog.fs
 ```
 
 Then add the following line to projects with `paket.references` file you want FsLibLog to be available to.
 
-```
+```paket
 File: FsLibLog.fs
 ```
 
-
 ### 2. Replace its namespace with yours
 
 To alleviate potential naming conflicts, it's best to replace FsLibLog namespace with your own.
@@ -41,10 +47,9 @@ Target.create "Replace" <| fun _ ->
     (!! "paket-files/TheAngryByrd/FsLibLog/src/FsLibLog/FsLibLog.fs")
 ```
 
-
 ## Using in your library
 
-### Open namespaces 
+### Open namespaces
 
 ```fsharp
 open FsLibLog
@@ -55,14 +60,13 @@ open FsLibLog.Types
 
 There are currently three ways to get a logger.
 
-- `getCurrentLogger` - __Deprecated__ because inferring the correct StackFrame is too difficult. Creates a logger. It's name is based on the current StackFrame. 
+- `getCurrentLogger` - __Deprecated__ because inferring the correct StackFrame is too difficult. Creates a logger. It's name is based on the current StackFrame.
 - `getLoggerByFunc` - Creates a logger based on `Reflection.MethodBase.GetCurrentMethod` call.  This is only useful for calls within functions.
 - `getLoggerByQuotation` - Creates a logger given a Quotations.Expr type. This is only useful for module level declarations.
 - `getLoggerFor` - Creates a logger given a `'a` type.
 - `getLoggerByType` - Creates a logger given a `Type`.
 - `getLoggerByName` - Creates a logger given a `string`.
 
-
 ### Set the loglevel, message, exception and parameters
 
 Choose a LogLevel. (Fatal|Error|Warn|Info|Debug|Trace).
@@ -81,16 +85,15 @@ logger.warn(
 The set of functions to augment the `Log` record are
 
 - `Log.setMessage` - Amends a `Log` with a message
+- `Log.setMessageIntepolated` - Ammends `Log` with a message. Using the syntax of `{variableName:loggerName}` it will automatically convert an intermpolated string into a proper message template.
 - `Log.setMessageThunk` - Amends a `Log` with a message thunk.  Useful for "expensive" string construction scenarios.
 - `Log.addParameter` - Amends a `Log` with a parameter.
 - `Log.addParameters` - Amends a `Log` with a list of parameters.
 - `Log.addContext` - Amends a `Log` with additional named parameters for context. This helper adds more context to a log.  This DOES NOT affect the parameters set for a message template. This is the same calling OpenMappedContext right before logging.
 - `Log.addContextDestructured` - Amends a `Log` with additional named parameters for context. This helper adds more context to a log. This DOES NOT affect the parameters set for a message template. This is the same calling OpenMappedContext right before logging. This destructures an object rather than calling `ToString()` on it.  WARNING: Destructring can be expensive
 - `Log.addException` - Amends a `Log` with an exception.
 
-
-
-### Full Example:
+### Full Example
 
 ```fsharp
 namespace SomeLib
@@ -162,6 +165,17 @@ module Say =
                 >> Log.addException  e
             )
 
+    // Example Log Output:
+    // 2021-09-15T20:34:14.9060810-04:00 [Information] <SomeLib.Say> () The user {"Name": "Ensign Kim", "$type": "AdditionalData"} has requested a reservation date of "2021-09-16T00:34:14.8853360+00:00"
+    let interpolated (person : AdditionalData) (reservationDate : DateTimeOffset) =
+        // Starts the log out as an Info log
+        logger.info(
+            // Generates a message template via a specific string intepolation syntax.
+            // Add the name of the property after the expression
+            // for example: "person" will be logged as "user" and "reservationDate" as "reservationDate"
+            Log.setMessageI $"The user {person:User} has requested a reservation date of {reservationDate:ReservationDate} "
+        )
+
     // Has the same logging output as `hello`, above, but uses the Operators module.
     let helloWithOperators name =
         // Initiate a log with a message
@@ -178,95 +192,127 @@ module Say =
 
 ```
 
+## Log Providers
 
-## Currently supported providers
+Providers are the actual logging framework that sends the logs to some destination (console, file, logging service). FsLibLog uses reflection to inspect the running application and wire these up telling FsLibLog to do it.
+
+### Currently supported provider
 
 - [Serilog](https://github.com/serilog/serilog)
 
+### Custom Providers
+
+You can implement and teach FsLibLog about your own custom provider if one is not listed. You have to do 2 things:
+
+1. You have to implement the `ILogProvider` interface. [Example Implemenation](https://github.com/TheAngryByrd/FsLibLog/blob/master/examples/ConsoleExample/Program.fs#L5-L90)
+2. You have to tell FsLibLog to use it. [Example calling FsLibLog.LogProvider.setLoggerProvider](https://github.com/TheAngryByrd/FsLibLog/blob/master/examples/ConsoleExample/Program.fs#L94)
+  a. One downside to this is you need to do this for every library your application consumes that uses FsLiblog.
+
 ---
 
+## String Interpolation
+
+This allows for [string interpolation](https://docs.microsoft.com/en-us/dotnet/fsharp/language-reference/interpolated-strings) with a special syntax to be convertable to [Message Templates](https://messagetemplates.org/) used in underlying providers (such as Serilog).
+
+Typically when one uses string interpolation it works as such:
+
+```fsharp
+let favoriteCartoon = "Captain Planet"
+let dayItsOn = "Saturday"
+printfn $"My favorite cartoon is {favoriteCartoon} and airs on {dayItsOn}"
+```
+
+F# compiler will create a [FormattableString](https://docs.microsoft.com/en-us/dotnet/api/system.formattablestring?view=net-5.0) where it's `Format` property looks like `My favorite cartoon is {0} and airs on {1}` and the `GetArguments()` are `[| "Captain Planet";  "Saturday" |]`.  As you can see, `FormattableString` doesn't have the named parameters that `Message Templates` would want.  To make this work the way we want we need to introduce a specific syntax.
+
+```fsharp
+let favoriteCartoon = "Captain Planet"
+let dayItsOn = "Saturday"
+printfn $"My favorite cartoon is {favoriteCartoon:CartoonShow} and airs on {dayItsOn:DayAired}"
+```
+
+`setMessageInterpolated` will make the template look like `My favorite cartoon is {CartoonShow} and airs on {DayAired}`.  This will replace the number arguments with the names after the colon within the interpolated string. This makes a usable message template.
+
+- Why aren't we just trying to get the name of the variable/value? Needing to specify dedicate names _is a good thing_ since refactoring your variable names can have drastic effects on your logging queries. Explicit naming separates these concerns.
+
 ## Builds
 
 GitHub Actions |
 :---: |
 [![GitHub Actions](https://github.com/TheAngryByrd/FsLibLog/workflows/Build%20master/badge.svg)](https://github.com/TheAngryByrd/FsLibLog/actions?query=branch%3Amaster) |
 [![Build History](https://buildstats.info/github/chart/TheAngryByrd/FsLibLog)](https://github.com/TheAngryByrd/FsLibLog/actions?query=branch%3Amaster) |
 
-
 ---
 
 ### Building
 
-
 Make sure the following **requirements** are installed in your system:
 
-* [dotnet SDK](https://www.microsoft.com/net/download/core) 2.0 or higher
-* [Mono](http://www.mono-project.com/) if you're on Linux or macOS.
+- [dotnet SDK](https://www.microsoft.com/net/download/core) 2.0 or higher
+- [Mono](http://www.mono-project.com/) if you're on Linux or macOS.
 
-```
+```bash
 > build.cmd // on windows
 $ ./build.sh  // on unix
 ```
 
 #### Environment Variables
 
-* `CONFIGURATION` will set the [configuration](https://docs.microsoft.com/en-us/dotnet/core/tools/dotnet-build?tabs=netcore2x#options) of the dotnet commands.  If not set it will default to Release.
-  * `CONFIGURATION=Debug ./build.sh` will result in things like `dotnet build -c Debug`
-* `GITHUB_TOKEN` will be used to upload release notes and nuget packages to github.
-  * Be sure to set this before releasing
+- `CONFIGURATION` will set the [configuration](https://docs.microsoft.com/en-us/dotnet/core/tools/dotnet-build?tabs=netcore2x#options) of the dotnet commands.  If not set it will default to Release.
+  - `CONFIGURATION=Debug ./build.sh` will result in things like `dotnet build -c Debug`
+- `GITHUB_TOKEN` will be used to upload release notes and nuget packages to github.
+  - Be sure to set this before releasing
 
 ### Watch Tests
 
 The `WatchTests` target will use [dotnet-watch](https://github.com/aspnet/Docs/blob/master/aspnetcore/tutorials/dotnet-watch.md) to watch for changes in your lib or tests and re-run your tests on all `TargetFrameworks`
 
-```
+```bash
 ./build.sh WatchTests
 ```
 
 ### Releasing
-* [Start a git repo with a remote](https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/)
 
-```
+- [Start a git repo with a remote](https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/)
+
+```bash
 git add .
 git commit -m "Scaffold"
 git remote add origin origin https://github.com/user/MyCoolNewLib.git
 git push -u origin master
 ```
 
-* [Add your nuget API key to paket](https://fsprojects.github.io/Paket/paket-config.html#Adding-a-NuGet-API-key)
+- [Add your nuget API key to paket](https://fsprojects.github.io/Paket/paket-config.html#Adding-a-NuGet-API-key)
 
-```
+```bash
 paket config add-token "https://www.nuget.org" 4003d786-cc37-4004-bfdf-c4f3e8ef9b3a
 ```
 
-* [Create a GitHub OAuth Token](https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/)
-    * You can then set the `GITHUB_TOKEN` to upload release notes and artifacts to github
-    * Otherwise it will fallback to username/password
+- [Create a GitHub OAuth Token](https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/)
+  - You can then set the `GITHUB_TOKEN` to upload release notes and artifacts to github
+  - Otherwise it will fallback to username/password
 
+- Then update the `RELEASE_NOTES.md` with a new version, date, and release notes [ReleaseNotesHelper](https://fsharp.github.io/FAKE/apidocs/fake-releasenoteshelper.html)
 
-* Then update the `RELEASE_NOTES.md` with a new version, date, and release notes [ReleaseNotesHelper](https://fsharp.github.io/FAKE/apidocs/fake-releasenoteshelper.html)
-
-```
+```markdown
 #### 0.2.0 - 2017-04-20
 * FEATURE: Does cool stuff!
 * BUGFIX: Fixes that silly oversight
 ```
 
-* You can then use the `Release` target.  This will:
-    * make a commit bumping the version:  `Bump version to 0.2.0` and add the release notes to the commit
-    * publish the package to nuget
-    * push a git tag
+- You can then use the `Release` target.  This will:
+  - make a commit bumping the version:  `Bump version to 0.2.0` and add the release notes to the commit
+  - publish the package to nuget
+  - push a git tag
 
-```
+```bash
 ./build.sh Release
 ```
 
-
 ### Code formatting
 
 To format code run the following target
 
-```
+```bash
 ./build.sh FormatCode
 ```
 

examples/SerilogExample/Program.fs

@@ -19,5 +19,7 @@ let main argv =
 
     Say.fail "DaiMon"
 
+    Say.interpolated {Name = "Ensign Kim"} DateTimeOffset.UtcNow
+
     Console.ReadLine() |> ignore
     0

examples/SomeLib/Library.fs

@@ -1,6 +1,7 @@
 namespace SomeLib
 open FsLibLog
 open FsLibLog.Types
+open System
 
 module Say =
     // let logger = LogProvider.getLoggerByName "SomeLibrary.Say"
@@ -65,3 +66,14 @@ module Say =
                 // Adds an exception to the log
                 >> Log.addException  e
             )
+
+    // Example Log Output:
+    // 2021-09-15T20:34:14.9060810-04:00 [Information] <SomeLib.Say> () The user {"Name": "Ensign Kim", "$type": "AdditionalData"} has requested a reservation date of "2021-09-16T00:34:14.8853360+00:00"
+    let interpolated (person : AdditionalData) (reservationDate : DateTimeOffset) =
+        // Starts the log out as an Info log
+        logger.info(
+            // Generates a message template via a specific string intepolation syntax.
+            // Add the name of the property after the expression
+            // for example: "person" will be logged as "user" and "reservationDate" as "reservationDate"
+            Log.setMessageI $"The user {person:User} has requested a reservation date of {reservationDate:ReservationDate} "
+        )

paket.dependencies

@@ -1,11 +1,7 @@
 source https://www.nuget.org/api/v2
 source https://api.nuget.org/v3/index.json
 storage: none
-clitool dotnet-mono 0.5.2
-clitool dotnet-sourcelink 2.8.1
-clitool dotnet-fantomas 2.8.0
-clitool dotnet-reportgenerator-cli 4.0.0-rc4
-nuget FSharp.Core 4.3.4
+nuget FSharp.Core 5.0
 nuget Expecto 8.7
 nuget SourceLink.Create.CommandLine 2.8.1 copy_local: true
 nuget YoloDev.Expecto.TestSdk 0.7.0