Use string scanner with baseparser #160

Job	Run time
Document	22s
Gem: 3.0 on ubuntu-latest	13s
Gem: head on ubuntu-latest	10s
Gem: 3.0 on macos-latest	28s
Gem: head on macos-latest	26s
Gem: 3.0 on windows-latest	1m 32s
Gem: head on windows-latest	1m 12s
ruby-versions / Generate Ruby versions	2s
Inplace: 2.5 on ubuntu-latest	24s
Inplace: 2.6 on ubuntu-latest	22s
Inplace: 2.7 on ubuntu-latest	26s
Inplace: 3.0 on ubuntu-latest	11s
Inplace: 3.1 on ubuntu-latest	13s
Inplace: 3.2 on ubuntu-latest	15s
Inplace: 3.3 on ubuntu-latest	15s
Inplace: head on ubuntu-latest	11s
Inplace: jruby on ubuntu-latest	39s
Inplace: jruby-head on ubuntu-latest	45s
Inplace: 2.5 on macos-latest	54s
Inplace: 2.6 on macos-latest	53s
Inplace: 2.7 on macos-latest	1m 3s
Inplace: 3.0 on macos-latest	31s
Inplace: 3.1 on macos-latest	23s
Inplace: 3.2 on macos-latest	22s
Inplace: 3.3 on macos-latest	27s
Inplace: head on macos-latest	27s
Inplace: jruby on macos-latest	42s
Inplace: jruby-head on macos-latest	1m 48s
Inplace: 2.5 on windows-latest	2m 22s
Inplace: 2.6 on windows-latest	2m 13s
Inplace: 2.7 on windows-latest	1m 56s
Inplace: 3.0 on windows-latest	1m 16s
Inplace: 3.1 on windows-latest	1m 19s
Inplace: 3.2 on windows-latest	2m 5s
Inplace: 3.3 on windows-latest	3m 14s
Inplace: head on windows-latest	1m 21s
Inplace: jruby on windows-latest	2m 9s
Inplace: jruby-head on windows-latest	2m 1s
	35m 32s

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