Build: Add a better parsing method

This will replace splitchapters.sh and pickchapter.sh with a unified
approach.

Makefile

@@ -1,7 +1,7 @@
 RST2PDF=/usr/bin/rst2pdf
 BDIR=build
 CACHECENTERC=../varnish-cache/bin/varnishd/cache_center.c
-PICK = "./util/pickchapter.sh"
+PICK = "./util/pickchapter2.igawk"
 
 # The following are chapter lists for the relevant versions of the PDFs.
 # Please note that they need to be exact. No extra spaces, case sensitive
@@ -57,7 +57,7 @@ sphinx: ${common} src/conf.py
 		rm $$a; \
 		touch $$a; \
 	done
-	util/splitchapters.sh ${rstsrc} src/
+	util/splitchapters.igawk -v dst=src/ < ${rstsrc}
 	sed -i 's/\.\. class:: handout//' src/*.rst
 	sphinx-build -b html -d build/doctrees   src/ build/html
 
@@ -95,11 +95,11 @@ ${BDIR}:
 
 ${BDIR}/varnish-%.pdf: ${common} ui/pdf.style
 	@echo Building PDFs for $*...
-	@${PICK} ${$*} | ${RST2PDF} -s ui/pdf.style -b2 -o $@
+	@${PICK} -v include=${$*} < ${rstsrc} | ${RST2PDF} -s ui/pdf.style -b2 -o $@
 
 ${BDIR}/varnish_slide-%.pdf: ${common} ui/pdf_slide.style
 	@echo Building PDF slides for $*...
-	@${PICK} ${$*} | ./util/strip-class.gawk | ${RST2PDF} -s ui/pdf_slide.style -b2 -o $@
+	@${PICK} -v include=${$*} < ${rstsrc} | ./util/strip-class.gawk | ${RST2PDF} -s ui/pdf_slide.style -b2 -o $@
 
 util/param.rst:
 	( sleep 2; echo param.show ) | varnishd -n /tmp/meh -a localhost:2211 -d | gawk -v foo=0 '(foo == 2) && (/^[a-z]/) {  printf ".. |default_"$$1"| replace:: "; gsub($$1,""); print; } /^200 / { foo++;}' > util/param.rst

util/parse.igawk

@@ -0,0 +1,53 @@
+#!/usr/bin/igawk
+
+BEGIN {
+	chapter=""
+	pos=0
+	last=""
+}
+
+/^==+$/ {
+	if (length(last) == length($0)) {
+		chapter_done(chapter);
+		chapterindex[nchapterindex++] = chapter
+		subchapterindex[nsubchapterindex++] = chapter
+		chapter=last;
+		subchapter=chapter
+	}
+}
+
+/^--+$/ || /^\.\.+$/ {
+	if (length(last) == length($0)) {
+		sub_chapter_done(subchapter);
+		subchapterindex[nsubchapterindex++] = chapter
+		subchapter=last;
+	}
+}
+
+{
+	content[pos++] = last
+	content["s:"subchapter,relpos["s:"subchapter]++] = last
+	content[chapter,relpos[chapter]++] = last
+	last = $0
+}
+
+END {
+	sub_chapter_done(subchapter);
+	chapter_done(chapter);
+	chapterindex[nchapterindex++] = chapter
+	subchapterindex[nsubchapterindex++] = chapter
+}
+
+function print_chapter(chap,output,		i) {
+	for (i=0;i<relpos[chap];i++) {
+		if (output != "") {
+			printf("%s\n",content[chap,i]) >> output
+		} else {
+			printf("%s\n",content[chap,i])
+		}
+	}
+}
+
+function print_sub_chapter(chap,output) {
+	print_chapter("s:"chap,output);	
+}

util/pickchapter2.igawk

@@ -0,0 +1,23 @@
+#!/usr/bin/igawk -f
+
+@include util/parse.igawk
+
+function chapter_done(chap) {
+}
+
+function sub_chapter_done(chap) {
+}
+
+END {
+	if (include != "*") {
+		print_chapter("");
+		split(include,includea,",");
+		for (a in includea) {
+			print_chapter(includea[a]);
+		}
+	} else {
+		for (i=0; i<nchapterindex; i++) {
+			print_chapter(chapterindex[i]);
+		}
+	}
+}

util/splitchapters.igawk

@@ -0,0 +1,32 @@
+#!/usr/bin/igawk -f
+
+# Splits chapters into individual files for each chapter and create an
+# index page for sphinx.
+#
+# Usage: util/splitchapters.igawk -v dst=src/ < varnish_book.rst
+
+@include util/parse.igawk
+
+BEGIN {
+	aidx = dst "/build/autoindex.rst"
+	print ".. toctree::" > aidx
+	print "\t:maxdepth: 1" >> aidx
+	print "" >> aidx
+}
+
+function chapter_done(chap) {
+	if (chap == "") {
+		return
+	}
+	chapterclean=chap
+	gsub("[^a-zA-Z0-9]","_",chapterclean)
+	path = dst chapterclean ".rst"
+	print ".. include:: util/param.rst" > path
+	print "" >> path
+	print_chapter(chap,path)
+	print "\t" chapterclean >> aidx
+}
+
+function sub_chapter_done(chap) {
+}
+