Add support for automatically rerendering

.gitignore

@@ -1,4 +1,4 @@
-result
+result*
 bin
 lib
 

README.md

@@ -0,0 +1,17 @@
+# Marka - Markup/LaTeX Rendering Made Simple
+`marka` is a tool for making it more convenient to work with Pandoc Markdown.
+This is to support the complete replacement of normal LaTeX workflows with Markdown, without loosing any features.
+
+## Usage
+Marka consists of two tools: `marka` and `marka-combine`
+The combiner is just like the preprocessor in C and is already called when using `marka` normally.
+To compile a file with marka, the basic call syntax is `marka file.md`, but for day-to-day rendering it is more convenient to use the `marka -w file.md` syntax, which will automatically rerender the file when any included file is changed.
+
+## Combination
+The only way Marka Markdown differs from Pandoc Markdown, is the inclusion of the `€[./file]` construct, which recursively adds files to the project, making it more natural to include source-files or other markdown files.
+This does break a bit with the convention of Markdown being readable as just a textfile, but is included because Marka Markdown is intended to replace LaTeX and many LaTeX project are too big to conveniently exist as a single file.
+It also allows the inclusion of parts of source-code or other documents, which helps keep a single-source-of-truth workflow, where external data is not copied into the documentation manually, which can result in mismatches between the document version of data and the real data.
+
+## Building
+Marka is set up to build via the Crystal build tool Shards, so a simple `shards install && shards build` should produce the binaries.
+There is also support for building via Nix, so a simple `nix build` will produce a derivation.

explorer.cr

@@ -1,18 +1,20 @@
-def explore(file : Path)
-    files = [] of Path
-    File.each_line file do |line|
-        match = /€\[([^]]+)\]/.match(line)
-        if ! match.nil?
-            path = Path[match[1]]
-            puts "Found #{path}"
-            if ! path.absolute?
-                path = (Path[file.dirname] / path).normalize
+module Explorer
+    def self.explore(file : Path)
+        files = [] of Path
+        File.each_line file do |line|
+            match = /€\[([^]]+)\]/.match(line)
+            if ! match.nil?
+                path = Path[match[1]]
+                puts "Found #{path}"
+                if ! path.absolute?
+                    path = (Path[file.dirname] / path).normalize
+                end
+                puts "Adding as #{path}"
+                files << path
+                files += explore(path)
             end
-            puts "Adding as #{path}"
-            files << path
-            files += explore(path)
         end
+        files
     end
-    files
 end
 

marka-cli.cr

@@ -1,8 +1,10 @@
 #!/usr/bin/env crystal
 
 require "option_parser"
+require "inotify"
 
 require "./marka"
+require "./explorer"
 
 marka = Marka.new
 
@@ -81,9 +83,41 @@ marka.bibliography = bib if File.exists? bib
 meta = target.sibling "meta.yml"
 marka.meta = meta if File.exists? meta
 
-result = marka.render target
-if !result.success?
-    STDERR.puts "Pandoc failed with status: #{result.exit_code}"
-    exit 2
+def render(m, t)
+    result = m.render t
+    if !result.success?
+        STDERR.puts "Pandoc failed with status: #{result.exit_code}"
+        exit 2
+    end
+end
+
+render marka, target
+
+if watch_mode
+    while true
+        files = [ target ] + Explorer.explore target
+
+        channel = Channel(Path).new
+
+        watchers = files.map do |file|
+            Inotify.watch file.to_s do |event|
+                if event.type.modify?
+                    channel.send(file)
+                end
+            end
+        end
+
+        change = channel.receive
+
+        watchers.each do |w|
+            w.close
+        end
+
+        channel.close
+
+        puts "Rerendering because #{change} changed"
+
+        render marka, target
+    end
 end
 

shard.yml

@@ -14,9 +14,9 @@ dependencies:
 
 targets:
     marka:
-        main: marka.cr
+        main: marka-cli.cr
     marka-combiner:
-        main: marka-combiner.cr
+        main: combiner-cli.cr
 
 license: GPLv3