feat: implement facet

DocGen4/Load.lean

@@ -19,20 +19,13 @@ Sets up a lake workspace for the current project. Furthermore initialize
 the Lean search path with the path to the proper compiler from lean-toolchain
 as well as all the dependencies.
 -/
-def lakeSetup (imports : List String) : IO (Except UInt32 Lake.Workspace) := do
+def lakeSetup : IO (Except UInt32 Lake.Workspace) := do
   let (leanInstall?, lakeInstall?) ← Lake.findInstall?
   match ←(EIO.toIO' <| Lake.mkLoadConfig {leanInstall?, lakeInstall?}) with
   | .ok config =>
     let ws : Lake.Workspace ← Lake.loadWorkspace config
       |>.run Lake.MonadLog.eio
       |>.toIO (λ _ => IO.userError "Failed to load Lake workspace")
-    let libraryLeanGitHash := ws.lakeEnv.lean.githash
-    if libraryLeanGitHash ≠ Lean.githash then
-      IO.println s!"WARNING: This doc-gen was built with Lean: {Lean.githash} but the project is running on: {libraryLeanGitHash}"
-    let _libs ← ws.runBuild (Lake.buildImportsAndDeps imports) false
-      |>.run (Lake.MonadLog.eio config.verbosity)
-      |>.toIO (λ _ => IO.userError "Failed to compile imports via Lake")
-    initSearchPath (←findSysroot) (ws.packageList.map (·.oleanDir))
     pure <| Except.ok ws
   | .error err =>
     throw <| IO.userError err.toString
@@ -62,4 +55,7 @@ def load (task : Process.AnalyzeTask) : IO (Process.AnalyzerResult × Hierarchy)
 
   Prod.fst <$> Meta.MetaM.toIO (Process.process task) config { env := env } {} {}
 
+def loadCore : IO (Process.AnalyzerResult × Hierarchy) := do
+  load <| .loadAll [`Init, `Std, `Lean]
+
 end DocGen4

Main.lean

@@ -11,17 +11,16 @@ def getTopLevelModules (p : Parsed) : IO (List String) :=  do
   pure topLevelModules
 
 def runSingleCmd (p : Parsed) : IO UInt32 := do
-    let relevantModules := [p.positionalArg! "module" |>.as! String]
-    let res ← lakeSetup (relevantModules)
-    match res with
-    | Except.ok ws =>
-      let relevantModules := relevantModules.map String.toName
-      let (doc, hierarchy) ← load (.loadAllLimitAnalysis relevantModules)
-      IO.println "Outputting HTML"
-      let baseConfig := getSimpleBaseContext hierarchy
-      htmlOutputResults baseConfig doc ws (p.hasFlag "ink")
-      pure 0
-    | Except.error rc => pure rc
+  let relevantModules := [p.positionalArg! "module" |>.as! String |> String.toName]
+  let res ← lakeSetup
+  match res with
+  | Except.ok ws =>
+    let (doc, hierarchy) ← load <| .loadAllLimitAnalysis relevantModules
+    IO.println "Outputting HTML"
+    let baseConfig := getSimpleBaseContext hierarchy
+    htmlOutputResults baseConfig doc ws (p.hasFlag "ink")
+    pure 0
+  | Except.error rc => pure rc
 
 def runIndexCmd (_p : Parsed) : IO UInt32 := do
   let hierarchy ← Hierarchy.fromDirectory Output.basePath
@@ -29,22 +28,22 @@ def runIndexCmd (_p : Parsed) : IO UInt32 := do
   htmlOutputIndex baseConfig
   pure 0
 
-def runDocGenCmd (p : Parsed) : IO UInt32 := do
-  let modules : List String := p.variableArgsAs! String |>.toList
-  if modules.length == 0 then
-    throw <| IO.userError "No modules provided."
-
-  let res ← lakeSetup modules
+def runGenCoreCmd (_p : Parsed) : IO UInt32 := do
+  let res ← lakeSetup
   match res with
   | Except.ok ws =>
-    IO.println s!"Loading modules from: {←searchPathRef.get}"
-    let modules := modules.map String.toName
-    let (doc, hierarchy) ← load (.loadAll modules)
+    let (doc, hierarchy) ← loadCore
     IO.println "Outputting HTML"
-    htmlOutput doc hierarchy ws (p.hasFlag "ink")
+    let baseConfig := getSimpleBaseContext hierarchy
+    htmlOutputResults baseConfig doc ws (ink := False) 
     pure 0
   | Except.error rc => pure rc
 
+def runDocGenCmd (_p : Parsed) : IO UInt32 := do
+  IO.println "You most likely want to use me via Lake now, check my README on Github on how to:"
+  IO.println "https://github.com/leanprover/doc-gen4"
+  return 0
+
 def singleCmd := `[Cli|
   single VIA runSingleCmd;
   "Only generate the documentation for the module it was given, might contain broken links unless all documentation is generated."
@@ -63,19 +62,19 @@ def indexCmd := `[Cli|
     ...topLevelModule : String; "The top level modules this documentation will be for."
 ]
 
+def genCoreCmd := `[Cli|
+  genCore VIA runGenCoreCmd;
+  "Generate documentation for the core Lean modules: Init, Std and Lean since they are not Lake projects"
+]
+
 def docGenCmd : Cmd := `[Cli|
-  "doc-gen4" VIA runDocGenCmd; ["0.0.1"]
+  "doc-gen4" VIA runDocGenCmd; ["0.1.0"]
   "A documentation generator for Lean 4."
 
-  FLAGS:
-    ink; "Render the files with LeanInk in addition"
-
-  ARGS:
-    ...modules : String; "The modules to generate the HTML for."
-
   SUBCOMMANDS:
     singleCmd;
-    indexCmd
+    indexCmd;
+    genCoreCmd
 ]
 
 def main (args : List String) : IO UInt32 :=

README.md

@@ -2,48 +2,15 @@
 Document Generator for Lean 4
 
 ## Usage
-You can call `doc-gen4` from the top of a Lake project like this:
-```sh
-$ /path/to/doc-gen4 Module
+`doc-gen4` is the easiest to use via its custom Lake facet, in order
+to do this you have to add it to your `lakefile.lean` like this:
 ```
-
-where `Module` is one or more of the top level modules you want to document.
-The tool will then proceed to compile the project using lake (if that hasn't happened yet),
-analyze it and put the result in `./build/doc`.
-
-You can optionally provide the path to a `LeanInk` binary using the `--ink` flag which will make
-the tool produce `Alectryon` style rendered output along the usual documentation.
-
-You could e.g. host the files locally with the built-in Python webserver:
-```sh
-$ cd build/doc && python -m http.server
+meta if get_config? env = some "dev" then -- dev is so not everyone has to build it
+require «doc-gen4» from git "https://github.com/leanprover/doc-gen4" @ "main"
 ```
-
-### Multi stage
-You can also use `doc-gen4` in multiple separate stages to generate the whole documentation.
-For example `mathlib4` consists out of 4 modules, the 3 Lean compiler ones and itself:
-- `Init`
-- `Std`
-- `Lean`
-- `Mathlib`
-
-The first build stage is to run doc-gen for all modules separately:
-
-1. `doc-gen4 single Init`
-2. `doc-gen4 single Std`
-3. `doc-gen4 single Lean`
-4. `doc-gen4 single Mathlib`
-
-Note that you can also just make a call to submodules so `Mathlib.Algebra`
-will work standalone as well. Furthermore one can use the `--ink` flag
-here to also generate LeanInk documentation in addition.
-
-The second and last stage is the index one which zips up some
-information relevant for the search:
-```sh
-$ doc-gen4 index Mathlib
+Then you can generate documentation for an entire library using:
 ```
-Now `build/doc` should contain the same files with the same context as if one had run
-```
-$ doc-gen4 Mathlib
+lake -Kenv=dev build Test:docs
 ```
+If you have multiple libraries you want to generate documentation for
+the recommended way right now is to run it for each library.

lakefile.lean

@@ -26,3 +26,92 @@ require lake from git
 
 require leanInk from git
   "https://github.com/hargonix/LeanInk" @ "doc-gen"
+
+module_facet docs (mod) : FilePath := do
+  let some docGen4 ← findLeanExe? `«doc-gen4»
+    | error "no doc-gen4 executable configuration found in workspace"
+  let exeJob ← docGen4.exe.fetch
+  let modJob ← mod.leanBin.fetch
+  let buildDir := (← getWorkspace).root.buildDir
+  let docFile := mod.filePath (buildDir / "doc") "html"
+  exeJob.bindAsync fun exeFile exeTrace => do
+  modJob.bindSync fun _ modTrace => do
+    let depTrace := exeTrace.mix modTrace
+    let trace ← buildFileUnlessUpToDate docFile depTrace do
+      logInfo s!"Documenting module: {mod.name}"
+      proc {
+        cmd := exeFile.toString
+        args := #["single", mod.name.toString, "--ink"]
+        env := #[("LEAN_PATH", (← getAugmentedLeanPath).toString)]
+      }
+    return (docFile, trace)
+
+-- TODO: technically speaking this facet does not show all file dependencies
+target coreDocs : FilePath := do
+  let some docGen4 ← findLeanExe? `«doc-gen4»
+    | error "no doc-gen4 executable configuration found in workspace"
+  let exeJob ← docGen4.exe.fetch
+  let basePath := (←getWorkspace).root.buildDir / "doc"
+  let dataFile := basePath / "declarations" / "declaration-data-Lean.bmp"
+  exeJob.bindSync fun exeFile exeTrace => do
+    let trace ← buildFileUnlessUpToDate dataFile exeTrace do
+      logInfo "Documenting Lean core: Init, Std, Lean"
+      proc {
+        cmd := exeFile.toString
+        args := #["genCore"]
+        env := #[("LEAN_PATH", (← getAugmentedLeanPath).toString)]
+      }
+    return (dataFile, trace)
+
+library_facet docs (lib) : FilePath := do
+  let some docGen4Pkg ← findPackage? `«doc-gen4»
+    | error "no doc-gen4 package found in workspace"
+  let some docGen4 := docGen4Pkg.findLeanExe? `«doc-gen4»
+    | error "no doc-gen4 executable configuration found in workspace"
+  let exeJob ← docGen4.exe.fetch
+
+  -- XXX: Workaround remove later
+  let coreJob ← if h : docGen4Pkg.name = _package.name then
+    have : Fact (docGen4Pkg.name = _package.name) := Fact.mk h
+    let job := fetch <| docGen4Pkg.target `coreDocs
+    job
+  else
+    error "wrong package"
+
+  let moduleJobs ← BuildJob.mixArray (α := FilePath) <| ← lib.recBuildLocalModules #[`docs]
+  -- Shared with DocGen4.Output
+  let basePath := (←getWorkspace).root.buildDir / "doc"
+  let dataFile := basePath / "declarations" / "declaration-data.bmp"
+  let staticFiles := #[
+    basePath / "style.css",
+    basePath / "declaration-data.js",
+    basePath / "nav.js",
+    basePath / "how-about.js",
+    basePath / "search.js",
+    basePath / "mathjax-config.js",
+    basePath / "instances.js",
+    basePath / "importedBy.js",
+    basePath / "index.html",
+    basePath / "404.html",
+    basePath / "navbar.html",
+    basePath / "find" / "index.html",
+    basePath / "find" / "find.js",
+    basePath / "src"  / "alectryon.css",
+    basePath / "src"  / "alectryon.js",
+    basePath / "src"  / "docutils_basic.css",
+    basePath / "src"  / "pygments.css"
+  ]
+  coreJob.bindAsync fun _ coreInputTrace => do
+    exeJob.bindAsync fun exeFile exeTrace => do
+      moduleJobs.bindSync fun _ inputTrace => do
+        let depTrace := mixTraceArray #[inputTrace, exeTrace, coreInputTrace]
+        let trace ← buildFileUnlessUpToDate dataFile depTrace do
+          logInfo "Documentation indexing"
+          proc {
+            cmd := exeFile.toString
+            args := #["index"]
+          }
+        let traces ← staticFiles.mapM computeTrace
+        let indexTrace := mixTraceArray traces
+
+        return (dataFile, trace.mix indexTrace)