    # comment
    rule b
    rule c
    #d
    rule c
    description=a
    rule d
      description = ds
      description = ds
      rule=ds
      description = ds
    rule b

    rule c

    rule c
     # ds
     ds=ds
    description=a
    rule d
      rule =description = ds

    rule b
      command = clang -MMD -MF $out.d -o $out -c $in
      description = building $out
      unknown = xyz

    rule dump
      command = sleep 1; ls -l /proc/self/fd; exit 1
      pool = link_pool
      # blah blah
      pool = console
      pool = $console

    rule xy-z_
    rule --xy-z_
    rule _xy-z_

    # error
    rule with error
    rule a:a
    rule a|a
    rule a$
    rule 0-@#d

    # browse_py.h is used to inline browse.py.
    rule inline
      command = "$root/src/inline.sh" $varname < $in > $out
      description = INLINE $out

    default foo bar
    default baz

    include ninja1.ninja

    subninja ninja2.ninja

    pool link_pool
      depth = 4
      xxx = d

    pool link_pool d
      depth = 4

    build a.o: b a.c

    build a.o|c: b a.c || a | b

    build a.o | c : b a.c | a || b

    build $a.o | $c : b $a.c | $a || $b

    build 0: sleep README

    build 1: sleep README

    build all: phony 0 1
    deps = xxx
    CMD = cc
    build all: phony 0 1

    build $builddir/browse_py.h: inline $root/src/browse.py | $root/src/inline.sh
      varname = kBrowsePy

    build $builddir/subprocess-posix.o: cxx $root/src/subprocess-posix.cc
    build $builddir/libninja.a: ar $builddir/browse.o $builddir/build.o $
        $builddir/build_log.o $builddir/clean.o $builddir/debug_flags.o $
        $builddir/depfile_parser.o $builddir/deps_log.o

    build $root/doc/manual.pdf: dblatex $builddir/manual.xml | $
        $root/doc/dblatex.xsl

    build out: cat in |@ validate1 validate2 |@ validate1 | dep
    build out: cat in || dep |@ validate

    builddir=/
    builddir =/
    builddir= /
    ldflags = -L$builddir

    xx x

    x = $a
    x = $-a_
    x = ${a}
    x = ${-a}
    x = $a@
    x = $@
    x = $$
    x = $:
    x = $ a
    x = $
        b
    x = $
        $
        a
    x = $
        $a
    x = $a a
    x = ${a} a
    x = $$ a
    x = $: a
    x = $! a
    x = ${a b ds
     x = a