Render groupedJobs to be friendlier to jq

Also update README with native rendering instructions for grouped jobs.

Author: akshaymankar

README.md

@@ -26,11 +26,13 @@ To use dhall-concourse you need to install [dhall-fly](https://github.com/akshay
 
 ### Using dhall-to-json and jq (Experimental)
 
+#### Jobs without Groups
+
 To use native rendering to render a list of jobs in a file called `jobs.dhall`, you'd have to write a dhall expression like this:
 
 ```dhall
 let Concourse = 
-      https://raw.githubusercontent.com/akshaymankar/dhall-concourse/0.3.0/package.dhall
+      https://raw.githubusercontent.com/akshaymankar/dhall-concourse/0.5.0/package.dhall
 
 let jobs = ./jobs.dhall
 
@@ -45,6 +47,28 @@ dhall-to-json <<< './pipeline.dhall' \
   | jq '.resource_types = (.resource_types|unique)'
 ```
 
+#### Jobs with groups
+
+Similarly, to render a list of `GroupedJob`s in a filed called `grouped-jobs.dhall`, this would be the expression to render:
+
+```dhall
+let Concourse = 
+      https://raw.githubusercontent.com/akshaymankar/dhall-concourse/0.5.0/package.dhall
+
+let groupedJobs = ./grouped-jobs.dhall
+
+in Concourse.render.groupedJobs groupedJobs
+```
+
+Now you can render this using dhall-to-json and jq like this:
+
+```bash
+dhall-to-json <<< './pipeline.dhall' \
+  | jq '.resources = (.resources|unique)' \
+  | jq '.resource_types = (.resource_types|unique)' \
+  | jq '.groups = (.groups | group_by(.name) | map({name: .[0].name, jobs: (map(.jobs) | flatten) }))'
+```
+
 ## Defining a pipeline
 
 ### Example 1: Hello World

package.dhall

@@ -11,7 +11,7 @@
       ./helpers/package.dhall sha256:94d9aab795fe7049da8c7904d6faa7c7be60ed10a59565c33d7cf9d026a6968d
     ? ./helpers/package.dhall
 , render =
-      ./render/package.dhall sha256:9817b38973cc0354670cbd0419ca79b19e6999d7d24ed92bb5b41dd60245f750
+      ./render/package.dhall sha256:380eab61bcc75473589242aa13011d0912f0634745f84c185296594c557bacb7
     ? ./render/package.dhall
 , extractors =
       ./extractors/package.dhall sha256:761aabbb030ca0fca473273e7c8b45c29dcd848388bdb767db7322a1243a5dd6

render/groupedJobs.dhall

@@ -9,17 +9,21 @@ in    λ(groupedJobs : List Types.GroupedJob)
               Types.Job
               (λ(groupedJob : Types.GroupedJob) → groupedJob.job)
               groupedJobs
-      
-      let jobGroups =
-            Prelude.List.map
+
+      let RenderedGroup = { name : Text, jobs : List Text }
+
+      let jobGroups
+          : List RenderedGroup
+          = Prelude.List.concatMap
               Types.GroupedJob
-              (Prelude.Map.Entry Text (List Text))
+              RenderedGroup
               (   λ(groupedJob : Types.GroupedJob)
-                → Prelude.Map.keyValue
-                    (List Text)
-                    groupedJob.job.name
+                → Prelude.List.map
+                    Text
+                    RenderedGroup
+                    (λ(g : Text) → { name = g, jobs = [ groupedJob.job.name ] })
                     groupedJob.groups
               )
               groupedJobs
-      
-      in  ./pipeline.dhall jobs ⫽ { jobGroups = jobGroups }
+
+      in  ./pipeline.dhall jobs ⫽ { groups = jobGroups }

render/package.dhall

@@ -23,6 +23,6 @@
       ./pipeline.dhall sha256:d66fb1637db9cf4680213b2b6939a5d5cff64b2f4e5d4e24444d49d40f92853e
     ? ./pipeline.dhall
 , groupedJobs =
-      ./groupedJobs.dhall sha256:807ef57f86ae37a22f7099a23c684ab45c59034c9dacfcd467b9b623e649ed6b
+      ./groupedJobs.dhall sha256:9d56b1f88ec737fa02cd8eddc5fa239fd89cb6c509130ea83295899c2ac49c26
     ? ./groupedJobs.dhall
 }