Cleaned up some terminology, whitespace, and added index.

Changed "compile-time warning" to "static warning"; eliminated spurious
space at the beginning of each normative paragraph; added index and
changed all `{\em ..}` containing defining occurrences of words and
phrases such that they are added to the index and marked with a
diamond in the margin (to make it easy to spot definitions).

Change-Id: I688561a24d2b9955f383d6c8db2c913353d41b4b
Reviewed-on: https://dart-review.googlesource.com/c/82501
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>

docs/language/.gitignore

@@ -1,4 +1,7 @@
 dartLangSpec*.aux
+dartLangSpec*.idx
+dartLangSpec*.ilg
+dartLangSpec*.ind
 dartLangSpec*.log
 dartLangSpec*.out
 dartLangSpec*.pdf

docs/language/Makefile

@@ -6,21 +6,25 @@ HASHER=../../tools/addlatexhash.dart
 
 pdf:
 	pdflatex $(SPEC)
+	makeindex $(NAME).idx
 	pdflatex $(SPEC)
 	pdflatex $(SPEC)
 
 pdfhash: hash_and_list
 	pdflatex $(HASH)
+	makeindex $(NAME)-hash.idx
 	pdflatex $(HASH)
 	pdflatex $(HASH)
 
 dvi:
 	latex $(SPEC)
+	makeindex $(NAME).idx
 	latex $(SPEC)
 	latex $(SPEC)
 
 dvihash: hash_and_list
 	latex $(HASH)
+	makeindex $(NAME)-hash.idx
 	latex $(HASH)
 	latex $(HASH)
 
@@ -35,8 +39,7 @@ help:
 	@echo "  clean: remove all generated files"
 
 cleanish:
-	rm -f *.aux *.log *.toc *.out
+	rm -f *.aux *.log *.toc *.out *.idx *.ilg
 
 clean: cleanish
-	rm -f *.dvi *.pdf $(HASH) $(LIST)
- 
+	rm -f *.dvi *.pdf *.ind $(HASH) $(LIST)

docs/language/dart.sty

@@ -78,7 +78,7 @@
 
 % Used as line break in the right hand side of a grammar
 % alternative, that is, when starting a "continuation line".
-\newcommand{\gnewline}{\\\mbox{}\qquad{}}
+\newcommand{\gnewline}{\leavevmode\\}
 
 % Metavariables for argument lists.
 \newcommand{\argumentList}[1]{\metavar{{#1}s}}
@@ -110,6 +110,17 @@
 % A commonly used name for an identifier
 \newcommand{\id}{\metavar{id}}
 
+% Used for defining occurrence of phrase, with customized index entry.
+\newcommand{\IndexCustom}[2]{%
+  \leavevmode\marginpar{\ensuremath{\diamond}}\emph{#1}\index{#2}}
+
+% Used for a defining occurrence of a phrase, adding it to the index.
+\newcommand{\Index}[1]{\IndexCustom{#1}{#1}}
+
+% Same appearance, but not adding an entry to the index.
+\newcommand{\NoIndex}[1]{
+  \leavevmode\marginpar{\ensuremath{\diamond}}\emph{#1}}
+
 % ----------------------------------------------------------------------
 % Support for hash valued Location Markers
 
@@ -128,14 +139,14 @@
 \definecolor{LMdim}{gray}{1.0}
 
 % insert location marker showing hash value of following paragraph
-\newcommand{\LMHash}[1]{%
-  \hspace{0pt}\marginpar{\raisebox{0.5ex}{\miniscule{\color{LMdim}#1}}}}
+\newcommand{\LMHash}[1]{\leavevmode\marginpar{\quad%
+    \raisebox{0.5ex}{\miniscule{\color{LMdim}#1}}\vspace{-2\baselineskip}}}
 
 % support convenient renewcommand
 \let\OriginalLMHash\LMHash
 
 % define a label, and show the associated logical location marker
 \newcommand{\LMLabel}[1]{%
-  \vspace{-\baselineskip}\hspace{0pt}\OriginalLMHash{\raisebox{10ex}{#1}}%
+  \vspace{-\baselineskip}\leavevmode\OriginalLMHash{\raisebox{10ex}{#1}}%
   \label{#1}}
 % ----------------------------------------------------------------------