Generate separate manpages for each nix subcommand

.gitignore

@@ -18,7 +18,8 @@ perl/Makefile.config
 /doc/manual/nix.json
 /doc/manual/conf-file.json
 /doc/manual/builtins.json
-/doc/manual/src/command-ref/nix.md
+/doc/manual/src/SUMMARY.md
+/doc/manual/src/command-ref/new-cli
 /doc/manual/src/command-ref/conf-file.md
 /doc/manual/src/expressions/builtins.md
 

doc/manual/generate-manpage.nix

@@ -1,34 +1,40 @@
+command:
+
 with builtins;
 with import ./utils.nix;
 
 let
 
   showCommand =
-    { command, section, def }:
-    "${section} Name\n\n"
+    { command, def, filename }:
+    "# Name\n\n"
     + "`${command}` - ${def.description}\n\n"
-    + "${section} Synopsis\n\n"
+    + "# Synopsis\n\n"
     + showSynopsis { inherit command; args = def.args; }
+    + (if def.commands or {} != {}
+       then
+         "where *subcommand* is one of the following:\n\n"
+         # FIXME: group by category
+         + concatStrings (map (name:
+           "* [`${command} ${name}`](./${appendName filename name}.md) - ${def.commands.${name}.description}\n")
+           (attrNames def.commands))
+         + "\n"
+       else "")
     + (if def ? doc
-       then "${section} Description\n\n" + def.doc + "\n\n"
+       then "# Description\n\n" + def.doc + "\n\n"
        else "")
     + (let s = showFlags def.flags; in
        if s != ""
-       then "${section} Flags\n\n${s}"
+       then "# Flags\n\n${s}"
        else "")
     + (if def.examples or [] != []
        then
-         "${section} Examples\n\n"
+         "# Examples\n\n"
          + concatStrings (map ({ description, command }: "${description}\n\n```console\n${command}\n```\n\n") def.examples)
-       else "")
-    + (if def.commands or [] != []
-       then concatStrings (
-         map (name:
-           "# Subcommand `${command} ${name}`\n\n"
-           + showCommand { command = command + " " + name; section = "##"; def = def.commands.${name}; })
-           (attrNames def.commands))
        else "");
 
+  appendName = filename: name: (if filename == "nix" then "nix3" else filename) + "-" + name;
+
   showFlags = flags:
     concatStrings
       (map (longName:
@@ -48,8 +54,20 @@ let
     "`${command}` [*flags*...] ${concatStringsSep " "
       (map (arg: "*${arg.label}*" + (if arg ? arity then "" else "...")) args)}\n\n";
 
+  processCommand = { command, def, filename }:
+    [ { name = filename + ".md"; value = showCommand { inherit command def filename; }; inherit command; } ]
+    ++ concatMap
+      (name: processCommand {
+        filename = appendName filename name;
+        command = command + " " + name;
+        def = def.commands.${name};
+      })
+      (attrNames def.commands or {});
+
 in
 
-command:
-
-showCommand { command = "nix"; section = "#"; def = command; }
+let
+  manpages = processCommand { filename = "nix"; command = "nix"; def = command; };
+  summary = concatStrings (map (manpage: "    - [${manpage.command}](command-ref/new-cli/${manpage.name})\n") manpages);
+in
+(listToAttrs manpages) // { "SUMMARY.md" = summary; }

doc/manual/local.mk

@@ -4,7 +4,7 @@ MANUAL_SRCS := $(call rwildcard, $(d)/src, *.md)
 
 # Generate man pages.
 man-pages := $(foreach n, \
-  nix-env.1 nix-build.1 nix-shell.1 nix-store.1 nix-instantiate.1 nix.1 \
+  nix-env.1 nix-build.1 nix-shell.1 nix-store.1 nix-instantiate.1 \
   nix-collect-garbage.1 \
   nix-prefetch-url.1 nix-channel.1 \
   nix-hash.1 nix-copy-closure.1 \
@@ -22,7 +22,7 @@ dummy-env = env -i \
 	NIX_SSL_CERT_FILE=/dummy/no-ca-bundle.crt \
 	NIX_STATE_DIR=/dummy
 
-nix-eval = $(dummy-env) $(bindir)/nix eval --experimental-features nix-command -I nix/corepkgs=corepkgs --store dummy:// --impure --raw --expr
+nix-eval = $(dummy-env) $(bindir)/nix eval --experimental-features nix-command -I nix/corepkgs=corepkgs --store dummy:// --impure --raw
 
 $(d)/%.1: $(d)/src/command-ref/%.md
 	@printf "Title: %s\n\n" "$$(basename $@ .1)" > $^.tmp
@@ -42,13 +42,17 @@ $(d)/nix.conf.5: $(d)/src/command-ref/conf-file.md
 	$(trace-gen) lowdown -sT man $^.tmp -o $@
 	@rm $^.tmp
 
-$(d)/src/command-ref/nix.md: $(d)/nix.json $(d)/generate-manpage.nix $(bindir)/nix
-	$(trace-gen) $(nix-eval) 'import doc/manual/generate-manpage.nix (builtins.fromJSON (builtins.readFile $<))' > $@.tmp
+$(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/command-ref/new-cli
+	$(trace-gen) cat doc/manual/src/SUMMARY.md.in | while IFS= read line; do if [[ $$line = @manpages@ ]]; then cat doc/manual/src/command-ref/new-cli/SUMMARY.md; else echo "$$line"; fi; done > $@.tmp
 	@mv $@.tmp $@
 
+$(d)/src/command-ref/new-cli: $(d)/nix.json $(d)/generate-manpage.nix $(bindir)/nix
+	@rm -rf $@
+	$(trace-gen) $(nix-eval) --write-to $@ --expr 'import doc/manual/generate-manpage.nix (builtins.fromJSON (builtins.readFile $<))'
+
 $(d)/src/command-ref/conf-file.md: $(d)/conf-file.json $(d)/generate-options.nix $(d)/src/command-ref/conf-file-prefix.md $(bindir)/nix
 	@cat doc/manual/src/command-ref/conf-file-prefix.md > $@.tmp
-	$(trace-gen) $(nix-eval) 'import doc/manual/generate-options.nix (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp
+	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-options.nix (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp
 	@mv $@.tmp $@
 
 $(d)/nix.json: $(bindir)/nix
@@ -61,7 +65,7 @@ $(d)/conf-file.json: $(bindir)/nix
 
 $(d)/src/expressions/builtins.md: $(d)/builtins.json $(d)/generate-builtins.nix $(d)/src/expressions/builtins-prefix.md $(bindir)/nix
 	@cat doc/manual/src/expressions/builtins-prefix.md > $@.tmp
-	$(trace-gen) $(nix-eval) 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp
+	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp
 	@mv $@.tmp $@
 
 $(d)/builtins.json: $(bindir)/nix
@@ -71,7 +75,17 @@ $(d)/builtins.json: $(bindir)/nix
 # Generate the HTML manual.
 install: $(docdir)/manual/index.html
 
-$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/custom.css $(d)/src/command-ref/nix.md $(d)/src/command-ref/conf-file.md $(d)/src/expressions/builtins.md
+# Generate 'nix' manpages.
+install: $(d)/src/command-ref/new-cli
+	for i in doc/manual/src/command-ref/new-cli/*.md; do \
+	  name=$$(basename $$i .md); \
+	  if [[ $$name = SUMMARY ]]; then continue; fi; \
+	  printf "Title: %s\n\n" "$$name" > $$i.tmp; \
+	  cat $$i >> $$i.tmp; \
+	  lowdown -sT man $$i.tmp -o $(mandir)/man1/$$name.1; \
+	done
+
+$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/command-ref/conf-file.md $(d)/src/expressions/builtins.md
 	$(trace-gen) mdbook build doc/manual -d $(docdir)/manual
 	@cp doc/manual/highlight.pack.js $(docdir)/manual/highlight.js
 

doc/manual/src/SUMMARY.md.in

@@ -62,7 +62,7 @@
     - [nix-instantiate](command-ref/nix-instantiate.md)
     - [nix-prefetch-url](command-ref/nix-prefetch-url.md)
   - [Experimental Commands](command-ref/experimental-commands.md)
-    - [nix](command-ref/nix.md)
+@manpages@
   - [Files](command-ref/files.md)
     - [nix.conf](command-ref/conf-file.md)
 - [Glossary](glossary.md)