Add functionality for including hints at the end of the pdf book

marijnh · marijnh · commit 57d213290480 · 2018-02-04T23:28:18.000+01:00
diff --git a/.gitignore b/.gitignore
@@ -6,6 +6,7 @@
 /pdf/hints.tex
 /pdf/book.*
 /pdf/book_mobile.*
+/pdf/*.log
 /book.pdf
 /book_mobile.pdf
 /html/[012]*.html
diff --git a/Makefile b/Makefile
@@ -35,10 +35,13 @@ test: html
 	@node src/check_links.js
 	@echo Done.
 
-book.pdf: $(foreach CHAP,$(CHAPTERS),pdf/$(CHAP).tex) pdf/book.tex $(patsubst img/%.svg,img/generated/%.pdf,$(SVGS))
+book.pdf: $(foreach CHAP,$(CHAPTERS),pdf/$(CHAP).tex) pdf/hints.tex pdf/book.tex $(patsubst img/%.svg,img/generated/%.pdf,$(SVGS))
 	#cd pdf && sh build.sh book > /dev/null
 	mv pdf/book.pdf .	
 
+pdf/hints.tex: $(foreach CHAP,$(CHAPTERS),$(CHAP).md) src/extract_hints.js
+	node src/extract_hints.js | node src/render_latex.js - > $@
+
 img/generated/%.pdf: img/%.svg
 	inkscape --export-pdf=$@ $<
 
diff --git a/pdf/book.tex b/pdf/book.tex
@@ -137,7 +137,7 @@
 
 \input{21_skillsharing.tex}
 
-%\input{hints.tex}
+\input{hints.tex}
 
 \backmatter
 
diff --git a/src/extract_hints.js b/src/extract_hints.js
@@ -0,0 +1,24 @@
+const {readdirSync, readFileSync} = require("fs")
+
+process.stdout.write("# Exercise Hints\n\nThe hints below might help when you are stuck with one of the exercises in this book. They don't give away the entire solution, but rather try to help you find it yourself.\n\n");
+
+for (let name of readdirSync(".")) {
+  if (!/^\d\d.*\.md$/.test(name)) continue
+
+  let file = readFileSync(name, "utf8")
+  let title = file.match(/(?:\n|^)# (.*?)\n/)[1], titleWritten = false
+
+  let curSubsection
+  let re = /\n### (.*?)\n|\{\{hint\n([^]+?)\nhint\}\}/g
+  while (m = re.exec(file)) {
+    if (m[1]) {
+      curSubsection = m[1]
+    } else {
+      if (!titleWritten) {
+        process.stdout.write(`## ${title}\n\n`)
+        titleWritten = true
+      }
+      process.stdout.write(`### ${curSubsection}\n\n${m[2].trim()}\n\n`)
+    }
+  }
+}
diff --git a/src/render_latex.js b/src/render_latex.js
@@ -5,10 +5,10 @@ let file, noStarch = false
 for (let arg of process.argv.slice(2)) {
   if (arg == "--nostarch") noStarch = true
   else if (file) throw new Error("Multiple input files")
-  else file = arg
+  else file = arg == "-" ? "/dev/stdin" : arg
 }
 if (!file) throw new Error("No input file")
-let chapter = /^\d{2}_([^\.]+)/.exec(file)
+let chapter = /^\d{2}_([^\.]+)/.exec(file) || [null, "hints"]
 
 let {tokens, metadata} = transformTokens(require("./markdown").parse(fs.readFileSync(file, "utf8"), {}), {
   defined: ["book", "tex"],
