From 527b2982e250a37396bfa2ea0ec0403eb69d84cd Mon Sep 17 00:00:00 2001
From: Steffen Forkmann <steffen.forkmann@msu-solutions.de>
Date: Fri, 13 Oct 2017 10:19:27 +0200
Subject: [PATCH] Use maps instead of lists in why command

---
 src/Paket.Core/PackageAnalysis/Why.fs | 50 +++++++++++++--------------
 src/Paket/Paket.fsproj                |  4 +--
 2 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/src/Paket.Core/PackageAnalysis/Why.fs b/src/Paket.Core/PackageAnalysis/Why.fs
index 603d16490d..b9e37e6a07 100644
--- a/src/Paket.Core/PackageAnalysis/Why.fs
+++ b/src/Paket.Core/PackageAnalysis/Why.fs
@@ -8,45 +8,43 @@ open Paket.Requirements
 
 open Chessie.ErrorHandling
 
-type AdjLblGraph<'a, 'b> = list<'a * list<('a * 'b)>>
+type AdjLblGraph<'a> = Map<PackageName , Map<PackageName, 'a>>
 
-type LblPath<'a, 'b> = 'a * LblPathNode<'a, 'b>
+type LblPath<'a> = PackageName * LblPathNode<'a>
 
-and LblPathNode<'a, 'b> =
-| LblPathNode of LblPath<'a, 'b>
-| LblPathLeaf of 'a * 'b
+and LblPathNode<'a> =
+| LblPathNode of LblPath<'a>
+| LblPathLeaf of PackageName * 'a
 
 module AdjLblGraph =
-    let adj n (g: AdjLblGraph<_, _>) =
-        g
-        |> List.find (fst >> (=) n)
-        |> snd
-
-    let removeEdge ((n1,n2): 'a * 'a) (g: AdjLblGraph<'a, 'b>) =
-        g
-        |> List.map (fun (n, es) -> 
-            if n1 <> n then 
-                (n,es)
-            else
-                (n,es |> List.filter (fst >> ((<>)n2))))
-
-    let rec paths start stop g : list<LblPath<_, _>> =
-        [ for (n, lbl) in adj start g do
+    let inline adj n (g: AdjLblGraph<_>) =
+        Map.find n g
+
+    let inline removeEdge (n1,n2) (g: AdjLblGraph<'b>) =
+        match Map.tryFind n1 g with
+        | None -> g
+        | Some v ->
+          let v' = v |> Map.remove n2
+          Map.add n1 v' g
+
+    let rec paths start stop g : list<LblPath<_>> =
+        [ for kv in adj start g do
+            let n, lbl = kv.Key, kv.Value
             if n = stop then yield (start, LblPathLeaf (stop, lbl))
             for path in paths n stop (removeEdge (start,n) g) do 
                 yield (start, LblPathNode path)]
 
-let depGraph (res : PackageResolver.PackageResolution) : AdjLblGraph<_,_> =
+let depGraph (res : PackageResolver.PackageResolution) : AdjLblGraph<_> =
     res
-    |> Seq.toList
-    |> List.map (fun pair -> pair.Key, (pair.Value.Dependencies 
-                                       |> Set.map (fun (p,v,f) -> p,(v,f)) 
-                                       |> Set.toList))
+    |> Seq.map (fun pair -> pair.Key, (pair.Value.Dependencies
+                                       |> Seq.map (fun (p,v,f) -> p,(v,f)) 
+                                       |> Map.ofSeq))
+    |> Map.ofSeq
 
 type WhyOptions = 
     { Details : bool }
 
-type DependencyChain = LblPath<PackageName, (VersionRequirement * FrameworkRestrictions)>
+type DependencyChain = LblPath<VersionRequirement * FrameworkRestrictions>
 
 [<CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
 module DependencyChain =
diff --git a/src/Paket/Paket.fsproj b/src/Paket/Paket.fsproj
index 4958001c23..ea154f70e0 100644
--- a/src/Paket/Paket.fsproj
+++ b/src/Paket/Paket.fsproj
@@ -33,9 +33,9 @@
     <StartAction>Project</StartAction>
     <StartArguments>install</StartArguments>
     <StartWorkingDirectory>C:\temp\Gu.Reactive</StartWorkingDirectory>
-    <StartArguments>update</StartArguments>
+    <StartArguments>why ncrontab</StartArguments>
     <StartWorkingDirectory>C:\proj\Paket</StartWorkingDirectory>
-    <StartWorkingDirectory>D:\temp\test</StartWorkingDirectory>
+    <StartWorkingDirectory>D:\code\bookstore\</StartWorkingDirectory>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <Optimize>true</Optimize>