Section 8.2, Paragraph 2, Sentence 2:
"In the interpreter this not so much of a problem, [...]"

I guess that should be:
"In the interpreter this _IS_ not so much of a problem, [...]"

FIXED

Section 8.2, example:
To produce the same output as Listing 8.1 the line:

print(filename + ": " + line)

should be changed to:

print(filename + ": " + line.trim)

Ch.8 Functions and Closures, p.147 [pdf 181], top line
replace "at most once" by "exactly once"
(appear implies at least once)

typo:
    in which an underscore used to represent
->  in which an underscore is used to represent

FIXED