Make concatenation obvious for debugging.
Add some notes about lexing.
Merge branch 'master' into lexer
Merge branch 'master' into lexer
Attempt to demonstrate correct collapsing. Fail.
Merge branch 'master' into lexer

Conflicts:
	Hammer.xcodeproj/project.pbxproj
	Hammer/HMRLaziness.h
Delay the lexer sub-grammars.
Terminate compaction recursion with `self`.
Compact alternation deeply.
Parenthesize alternation descriptions.
Merge branch 'master' into lexer

Conflicts:
	Hammer.xcodeproj/project.pbxproj
	Hammer/HMRAlternation.m
	Hammer/HMRParserCombinator.m
The test passes!
Avoid costly forwarding.
Test of incremental lexing.
Merge remote-tracking branch 'origin/master' into lexer
Add a test which triggers a weird crash.
Rename _nullability to _nullable.
Merge branch 'master' into lexer

Conflicts:
	Hammer/HMRParserCombinator.m
Did I really commit that?
More adventures in lexing.