PLP 4e Errata

This page contains a list of all known errors in the text.  To report additional bugs, send mail to . 

Main book

• Page 54, first line of displayed regular expression at bottom of page: replace “* non-/” with “non-* / | *⁺ non-(*, /)”.
• Page 56, 3rd line of Section 2.2.1: replace “covert” with “convert”.
• Page 84, 8th line up from the bottom: replace “for nonterminals” with “for terminals”.
• Page 99, Figure 2.29, line 8: replace “array [symbol, state]” with “array [state, symbol]”.
• Page 100, Figure 2.30, 25th line of derivation: replace “stmt_list → stmt” with “stmt_list → stmt_list stmt”.
• Page 171, Exercise 3.13, third-to-last line: replace “What does this program print?  What would it print if ...” with “What is the result of evaluating (A)?  What would the result be if ...”. 
• Page 180, second-to-last line, replace “contract” with “contrast”. 
• Page 400, Example 8.57. Replace with

  In OCaml, equivalent operations can be found in the List library:

  open List;;
  'a' :: ['b'];;	⟹	['a'; 'b']
  hd ['a'; 'b'];;	⟹	'a'
  hd [];;	⟹	run-time exception
  tl ['a'; 'b'; 'c'];;	⟹	['b'; 'c']
  tl ['a'];;	⟹	[]
  tl [];;	⟹	run-time exception
  ['a'; 'b'] @ ['c'; 'd']	⟹	['a'; 'b'; 'c'; 'd']

  Run-time exceptions may be caught by the program if desired, using techniques
  we will cover in Section 9.4.  OCaml programmers are encouraged, however, to
  avoid hd and tl in favor of the match construct (Section 11.4.4), which makes it
  easier to ensure, at compile time, that run-time exceptions will never occur.   _◽

• Page 499, last paragraph of Example 10.28: replace “in languages that use a uniform value model for class-type variables” with “in languages that use a uniform reference model for class-type variables”. 
• Page 579, signature for fold in Example 11.74: replace
  “val fold : ('a * 'b -> 'b) * 'b * 'a list -> 'b = <fun>” with
  “val fold : ('a * 'b -> 'a) * 'a * 'b list -> 'a = <fun>”. 
• Page 691, Exercise 13.9(a): replace “it is not sufficient” with “it suffices”.
• Page 691, Exercise 13.9(b): replace the entire question with “In that same figure, without volatile labels, explain why it suffices to enclose each thread’s code in a synchronized block for some common shared object O, but it does not suffice to enclose only the pairs of reads in C and D.
• Page 715, Figure 14.3, line 10: replace “i == 0” with “i == 1”.
• Page 715, one line before Example 14.21: replace “NR” with “NF”.
• Page 723, displayed code fragment: replace “PS” with “ps”.
• Page 786, Figure 15.6:
  1. replace the current productions for read, write, and writeln with
     
     call : stmt₁ → id expr stmt₂
     
     • expr.next_free_reg := stmt₂.next_free_reg := stmt₁.next_free_reg
     • stmt₁.code := expr.code + [“a1 :=” expr.reg] + [“call” id.stp→symbol] + stmt₂.code
     call : expr₁ → id expr₂
     
     • expr₂.next_free_reg := expr₁.next_free_reg
     • expr₁.reg := reg_names[expr₁.next_free_reg mod k]
       expr₁.code := expr₂.code + [“a1 :=” expr₂.reg] + [“call” id.stp→symbol] + [expr₁.reg “:= rv”]
     null : expr → ε
     
     • expr.reg := “r1”       −− harmless₀
       expr.code := null
     
     
  2. in the productions for assign and id, replace “stp→name” with “stp→symbol”.
  3. in the productions for <>, >, and −, erase the right-triangle glyph.
• Page 787, Figure 15.6 (continued): replace the first four lines with
  
  macro handle_op(ref result, L_operand, R_operand : syntax_tree_node; op : string)
  
  • L_operand.next_free_reg := result.next_free_reg₀
    R_operand.next_free_reg := result.next_free_reg + 1₀
  • result.reg := L_operand.reg
• Page 789, Figure 15.7:
  1. replace lines 8–14 (the ones right after “main:”) with

     a1 := r1         −− harmless
     call getint      −− “getint” and “putint” are library subroutines
                          −− to be found by the linker
     r1 := rv
     i := r1
     a1 := r1         −− harmless
     call getint
     r1 := rv
     j := r1

  2. replace the last 7 lines with

     r1 := i
     a1 := r1
     call putint
     goto exit         −− return to operating system

  NB: Errata on pages 786, 787, and 789 “go together.”  Corrected images of these three pages are available HERE.
• Page 790: delete “Check Your Understanding” question number 7.  (The answer is no longer covered in this edition.) 
• Page 811: second full paragraph, line 10: replace “easily if” with “easily than it could if”.

Companion site

• Page C-29, Figure 3.18: in the code at right, move “char J;” from the beginning of F1 to the beginning of F2.  Also, in the table at left, in the first J entry, change the scope number from 5 to 6. 
• Page C-259, 3rd line of second paragraph under “Internet Alphabet Soup”: replace “Wide Wide” with “Wide Web”. 
• Page C-316, Figure 17.6: in Block 3, insert “φ” before each of the left parentheses.
• Page C-346, Figure 17.19:

  replace	“v19	with	“v19	; replace	“v26	with	“v26	.
  	r4”		r0”		r5”		r1”

• Page C-346, Figure 17.20,

  left column, line 3: replace	“∗r5 := 1”	with	“∗r1 := 1”	;
  left column, lines 8 & 9: replace	“r5 := r4 << 1	with	“r5 := r0 << 1	;
  	r3 := r4”		r3 := r0”
  left column, line 14: replace	“r6 := r4 div r2”	with	“r6 := r0 div r2”	;
  right column, line 1: replace	“r5 := r5 + 4”	with	“r1 := r1 + 4”	;
  right column, lines 3 & 4: replace	“r4 := r6 x r3	with	“r0 := r6 x r3	;
  	∗r5 := r6”		∗r1 := r6”
  right column, lines 10 & 11: replace	“r6 := r4 div r2	with	“r6 := r0 div r2	.
  	∗(r5+4) := r6”		∗(r1+4) := r6”

  NB: A corrected image of page C-346 is available HERE.

Thanks to Carl Albing, Wentao Cai, Nicholas Coleman, Chen Ding, Samuel Estep, Alexander Gutierrez, Lucian Ilie, Andrew Jarvis, Shuo (Max) Li, Sreepathi Pai, Colin Pronovost, Amila Senadheera, Ben Steele, Yanling Wang, and Zhizhou Zhang for their help in catching these mistakes.

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Last Change: 10 September 2024 /