Errata

Immediately following the last "NOTE" box in this section, the text reads:

"The first code line in the file defines the package for the type, named intro."

This refers to the listing for upper1.scala. In the listing shown, however, the package is named introscala.

Note from the Author or Editor:
Correct. Should be "... named introscala."

Now reads:

Revision History for the <em>First</em> Edition:
2014-11-25: First release
2015-03-27: Second release

Should read:

Revision History for the <strong>Second</strong> Edition:
2014-11-25: First release
2015-03-27: Second release

"Because map takes a single function argument, where the function itself takes a single argument." is a clause. I think removing the leading "Because" will fix it.

Note from the Author or Editor:
Yes, change "Because" to "The".

s/imaging/imagine/

Note from the Author or Editor:
correct

The package in the scala code Shapes.scala is defined as

package progscala2.introscala.shapes

However in page 21 the code states
import progscala2.intro.shapes._
import progscala2.intro.shapes._

as you can see progscala2.intro != progscala2.introscala

As a result the code in the book will not work.

I apologize for selecting serious technical mistake when it may be a simple problem.

But for new people learning the language, it may be frustrating. :)

Thank you and more power.

Note from the Author or Editor:
The line on page 21:
scala> import progscala2.intro.shapes._

should be
scala> import progscala2.introscala.shapes._

s/to to/to do/

Note from the Author or Editor:
correct.

The Person class example given on page 33 is correct.
But the code in the git repository says:
// src/main/scala/progscala2/typelessdomore/person.sc
says class Person(val mame: String, var age: Int)
note name is typed as mame, while later in the same file it is referred as name..

Note from the Author or Editor:
Yes, it should be "name".

s/can want to/can/

Note from the Author or Editor:
Doh! correct

"This function avoids the risk of throwing a MathError exception..."
'MathError' should probably be MatchError

"A MathError is only thrown..."
Same here

Note from the Author or Editor:
Damn. It should be MatchError.

The text shows MathError when it should show MatchError

Note from the Author or Editor:
yes.

On page 46, line 5 (excluding white spaces) of the formatted code example should be p.age and not p.lastName

Note from the Author or Editor:
Correct. It should be "p.age". Copy, paste error...

The last sentence in paragraph 3 reads as "Fortunately, Java 8 finally adds clojures to Java.". I think, this is what the author meant "Fortunately, Java 8 finally adds closures to Java."

Note from the Author or Editor:
Doh! Yes, "closures" is the correct work.

s/three useful type/three useful types/ (add an 's' to "type").

Note from the Author or Editor:
Correct.

whether or not the we process the files

should be

whether or not we process the files

Note from the Author or Editor:
Yes, delete the "the".

"enhancment" should be "enhancement".

Note from the Author or Editor:
correct

The example:
for {
x <- Seq(1, 2, 2.7, "one", "two", 'four)
} {
val str = x match {
case _: Int | _: Double => "a number: "+x
case "one"
=> "string one"
case _: String
=> "other string: "+x
case _
=> "unexpected value: " + x
}
println(str)
}

point to file // src/main/scala/progscala2/patternmatching/match-variable2.sc
Actually this code is in the file // src/main/scala/progscala2/patternmatching/match-variable3.sc
same needs to be updated in match-variable3.sc file in the comment.

Note from the Author or Editor:
Correct. The comment should say match-variable3.sc

The github source is missing the file src/main/scala/progscala2/patternmatching/infix.sc.

Note from the Author or Editor:
This file was actually in src/main/scala/progscala2/rounding. I moved it to patternmatching in the Github repo, so no change to the book's text is required.

The $ is missing for title in println for MagazineExtractorRE i.e.
case MagazineExtractorRE(title, issue) => println(s"""Magazine "title", issue $issue""")
should be
case MagazineExtractorRE(title, issue) => println(s"""Magazine "$title", issue $issue""")

Note from the Author or Editor:
Correct, the source file is missing the $ as shown. I've fixed the source in the Git repo.

This string "list double" is in result of code snippet page 132. But this string in not in code. It is copy past error.

Note from the Author or Editor:
Correct. Will fix in final version.

...use map for a a custom target...

Has a redundant 'a'

Note from the Author or Editor:
Yes, there's a redundant "a".

The overridingConversion code could not be found

Note from the Author or Editor:
The wrong source file was included here (i.e., the previous file was included in the text twice). There are only two changes, however:

1. The comment with the file name should end with .../implicit-conversions-resolution2.sc
2. There is a new line of text before the definition of "class O":

implicit def overridingConversion(s: String): Foo = Foo("Boo: "+s)

First, we won�t hande arrays or nested objects, just �flat� JSON expressions like {"a": "A", "b": 123, "c": 3.14159}

May be - First, we won�t HANDLE arrays or nested objects, .....

Note from the Author or Editor:
Fixed.

As mentioned curried-func.sc is not in // src/main/scala/progscala2/fp/datastructs/curried-func.sc but in // src/main/scala/progscala2/fp/curry/curried-func.sc

Note from the Author or Editor:
Correct. It's in the fp/curry location.

foldLeft and foldRight are mentioned, but the accompanying code sample implements reduceLeft and reduceRight.

Note from the Author or Editor:
Correct. The text before the example should say reduceLeft and reduceRight

The comment mentions expr1, whereas the implementation mentions expr

Note from the Author or Editor:
pg 223 in my PDF. Actually the 2nd and 3rd examples on the page have this issue. For consistency with the rest of the example, I would change the code, not the comments.
2nd example becomes: expr1 map { case pat => expr2 }
3rd example becomes: expr1 foreach { case pat => expr2 }

The first sentence mentions three distinct things, but the second paragraph starts of with "Both" as though covering only two things.

I suspect Validation was added after Either and Try but this particular text was not adjusted accordingly.

Note from the Author or Editor:
Thanks for adding the extra detail. I found the issue. It's the 1st paragraph on page 239 in my PDF. Yes, instead of "both" starting the 2nd sentence, it should say "All three".

Following up on previous errata...

The paragraph begins with:

Either, Try, and Validation express through types a fuller picture of how the program actually behaves. Both say that a valid value ...

In this case I believe "Both say" should be replaced with something like "They say", since more than two subjects are involved.

Note from the Author or Editor:
Thanks, confirmed after the added details in the previous bug report.

"also call" should be "also called"

Note from the Author or Editor:
Already fixed in the latest printing.

The start of the fourth paragraph repeats what is stated in the third paragraph.

Note from the Author or Editor:
Page 244 in my PDF. Correct. the third paragraph could be deleted completely:

If an object and a class have the same name and are defined in the same file, they are called companions.

There appears to be markup in the text

<emphasis role="keep-together">contract</emphasis>]

Note from the Author or Editor:
Wow! It's near the bottom of page 284 in my PDF. The word "contract" should be in italics/emphasis without the HTML tags.

The fourth line of second paragraph:

attempts to use override val name = "foo"

I think it should be

override var name = "foo"

i.e. an attempt to use var to override a parameterless method will get an error

Note from the Author or Editor:
Correct, it should be "var" not "val". There is also another typo in the first sentence of the same paragraph, "... writer method, override name_=, ..." There should be a "def" between "override" and "name".

the source code included is :
// src/main/scala/progscala2/basicoop/ValueClassPhoneNumber.sc

But it shoud be

// src/main/scala/progscala2/objectsystem/value-class-universal-traits.sc

Note from the Author or Editor:
Fixed in the Github repo.

"Vector is implemented using as a"

Either using or as should be removed.

Note from the Author or Editor:
Yes, wording needs cleaning up.

..."so if we map it to a a set"...

One of the "a"s is redundant.

Note from the Author or Editor:
Ah yes. Thanks.

(The page number is the printed page number in the PDF; it's the "physical" page 505.)

The sentence: "Use -encoding UTF8 if you use non-ASCII characters in names or the allowed symbols, such as ⇒ (Unicode \u21D2) instead of =&gt;." should instead end with "... =>."

Broken link to sbt-web in
'By now you’ve installed SBT. If you do JVM-based web development, see also the new sbt-web project"
->https://github.com/sbt/sbt-web$$

Note from the Author or Editor:
The dollar signs "$$" shouldn't be at the end of the URL. I don't know how they got there.

In example for-validations-good-form.sc, the if condition in function validName should be

if (n.length > 0 && n.matches("""^\p{Alpha}+$""")) Success(List(key -> n))

instead of

if (n.length > 0 && n.matches("""^\p{Alpha}$""")) Success(List(key -> n))

The symbol "+" is missed.

Note from the Author or Editor:
Yes, the + should be in the triple-quoted string: ""^\p{Alpha}+$"""

First sentence: "... that manipulates programs, rather than data", should really read "that manipulates programs as data".

"... we'll focus on the most stable parts: runtime reflection..." Change "runtime" to "runtime and compile-time" (drop the hyphen if you prefer...)

" scala.reflect.api.Types.TypeRef and scala.reflect.api.Symbols.TypeSymbol" should be " scala.reflect.api.Types#TypeRef and scala.reflect.api.Symbols#TypeSymbol". That is, the last period in each name should be a # instead. The links work correctly, fortunately.

"These types are being deprecated." Change to "These types will be deprecated eventually."

"... syntax expands the list into comma-separated values" should be "... syntax expands the list into a list of trees"

"Recall that we said that macros are a limited form of compiler plug-in" would be more accurately put, "Recall that we said that macros work like a limited form of compiler plug-in"