Help lint fixes for stricter help lint

basis/concurrency/messaging/messaging-docs.factor

@@ -53,7 +53,8 @@ ARTICLE: { "concurrency" "synchronous-sends" } "Synchronous sends"
 { $subsection reply-synchronous }
 "An example:"
 { $example
-    "USING: concurrency.messaging kernel threads ;"
+    "USING: concurrency.messaging kernel prettyprint threads ;"
+    "IN: scratchpad"
     ": pong-server ( -- )"
     "    receive [ \"pong\" ] dip reply-synchronous ;"
     "[ pong-server t ] \"pong-server\" spawn-server"

basis/help/tutorial/tutorial.factor

@@ -94,7 +94,7 @@ $nl
 "For example, we'd like it to identify the following as a palindrome:"
 { $code "\"A man, a plan, a canal: Panama.\"" }
 "However, right now, the simplistic algorithm we use says this is not a palindrome:"
-{ $example "\"A man, a plan, a canal: Panama.\" palindrome?" "f" }
+{ $unchecked-example "\"A man, a plan, a canal: Panama.\" palindrome?" "f" }
 "We would like it to output " { $link t } " there. We can encode this requirement with a unit test that we add to " { $snippet "palindrome-tests.factor" } ":"
 { $code "[ t ] [ \"A man, a plan, a canal: Panama.\" palindrome? ] unit-test" }
 "If you now run unit tests, you will see a unit test failure:"
@@ -106,12 +106,12 @@ $nl
 "Start by pushing a character on the stack; notice that characters are really just integers:"
 { $code "CHAR: a" }
 "Now, use the " { $link Letter? } " word to test if it is an alphabetical character, upper or lower case:"
-{ $example "Letter? ." "t" }
+{ $unchecked-example "Letter? ." "t" }
 "This gives the expected result."
 $nl
 "Now try with a non-alphabetical character:"
 { $code "CHAR: #" }
-{ $example "Letter? ." "f" }
+{ $unchecked-example "Letter? ." "f" }
 "What we want to do is given a string, remove all characters which do not match the " { $link Letter? } " predicate. Let's push a string on the stack:"
 { $code "\"A man, a plan, a canal: Panama.\"" }
 "Now, place a quotation containing " { $link Letter? } " on the stack; quoting code places it on the stack instead of executing it immediately:"

basis/locals/locals-docs.factor

@@ -134,6 +134,7 @@ $nl
 }
 "In a word with locals, literals expand into code which constructs the literal, and so every invocation pushes a new object:"
 { $example
+    "USE: locals"
     "IN: scratchpad"
     "TUPLE: person first-name last-name ;"
     ":: ordinary-word-test ( -- tuple )"

basis/math/complex/complex-docs.factor

@@ -6,7 +6,7 @@ ARTICLE: "complex-numbers-zero" "Embedding of real numbers in complex numbers"
 "Constructing a complex number with an imaginary component equal to an integer zero simply returns the real number corresponding to the real component:"
 { $example "USING: math prettyprint ;" "C{ 1 2 } C{ 3 -2 } + ." "4" }
 "Constructing a complex number with an imaginary component equal to floating point zero will still output a new complex number, however:"
-{ $example "USING: math prettyprint ;" "C{ 0.0 2.0 } C{ 0.0 1.0 } * ." "C{ 2.0 0.0 }" }
+{ $example "USING: math prettyprint ;" "C{ 0.0 2.0 } C{ 0.0 1.0 } * ." "C{ -2.0 0.0 }" }
 "Unlike math, where all real numbers are also complex numbers, Factor only considers a number to be a complex number if its imaginary part is non-zero. However, complex number operations are fully supported for real numbers; they are treated as having an imaginary part of zero." ;
 
 ARTICLE: "complex-numbers" "Complex numbers"

basis/math/libm/libm-docs.factor

@@ -5,8 +5,8 @@ ARTICLE: "math.libm" "C standard library math functions"
 "The words in the " { $vocab-link "math.libm" } " vocabulary call C standard library math functions. They are used to implement words in the " { $vocab-link "math.functions" } " vocabulary."
 $nl
 "They can be called directly, however there is little reason to do so, since they only implement real-valued functions, and in some cases place restrictions on the domain:"
-{ $example "2 acos ." "C{ 0.0 1.316957896924817 }" }
-{ $example "2 facos ." "0.0/0.0" }
+{ $example "USE: math.functions" "2 acos ." "C{ 0.0 1.316957896924817 }" }
+{ $example "USE: math.libm" "2 facos ." "0.0/0.0" }
 "Trigonometric functions:"
 { $subsection fcos }
 { $subsection fsin }

basis/stack-checker/stack-checker-docs.factor

@@ -21,7 +21,7 @@ $nl
 
 ARTICLE: "inference-combinators" "Combinator stack effects"
 "Without further information, one cannot say what the stack effect of " { $link call } " is; it depends on the given quotation. If the inferencer encounters a " { $link call } " without further information, a " { $link literal-expected } " error is raised."
-{ $example "[ dup call ] infer." "... an error ..." }
+{ $example "[ dup call ] infer." "Literal value expected\n\nType :help for debugging help." }
 "On the other hand, the stack effect of applying " { $link call } " to a literal quotation or a " { $link curry } " of a literal quotation is easy to compute; it behaves as if the quotation was substituted at that point:"
 { $example "[ [ 2 + ] call ] infer." "( object -- object )" }
 "Consider a combinator such as " { $link keep } ". The combinator itself does not have a stack effect, because it applies " { $link call } " to a potentially arbitrary quotation. However, since the combinator is declared " { $link POSTPONE: inline } ", a given usage of it can have a stack effect:"
@@ -35,7 +35,15 @@ $nl
 "Here is an example where the stack effect cannot be inferred:"
 { $code ": foo 0 [ + ] ;" "[ foo reduce ] infer." }
 "However if " { $snippet "foo" } " was declared " { $link POSTPONE: inline } ", everything would work, since the " { $link reduce } " combinator is also " { $link POSTPONE: inline } ", and the inferencer can see the literal quotation value at the point it is passed to " { $link call } ":"
-{ $example ": foo 0 [ + ] ; inline" "[ foo reduce ] infer." "( object -- object )" } ;
+{ $example ": foo 0 [ + ] ; inline" "[ foo reduce ] infer." "( object -- object )" }
+"Passing a literal quotation on the data stack through an inlined recursive combinator nullifies its literal status. For example, the following will not infer:"
+{ $example
+  "[ [ reverse ] swap [ reverse ] map swap call ] infer." "Literal value expected\n\nType :help for debugging help."
+}
+"To make this work, pass the quotation on the retain stack instead:"
+{ $example
+  "[ [ reverse ] [ [ reverse ] map ] dip call ] infer." "( object -- object )"
+} ;
 
 ARTICLE: "inference-branches" "Branch stack effects"
 "Conditionals such as " { $link if } " and combinators built on " { $link if } " present a problem, in that if the two branches leave the stack at a different height, it is not clear what the stack effect should be. In this case, inference throws a " { $link unbalanced-branches-error } "."
@@ -58,12 +66,14 @@ $nl
 $nl
 "If a recursive word takes quotation parameters from the stack and calls them, it must be declared " { $link POSTPONE: inline } " (as documented in " { $link "inference-combinators" } ") as well as " { $link POSTPONE: recursive } "."
 $nl
-"Furthermore, the input parameters which are quotations must be annotated in the stack effect. For example,"
-{ $see loop }
-"An inline recursive word cannot pass a quotation through the recursive call. For example, the following will not infer:"
-{ $code ": foo ( a b c -- d e f ) [ f foo drop ] when 2dup call ; inline" "[ 1 [ 1+ ] foo ] infer." }
+"Furthermore, the input parameters which are quotations must be annotated in the stack effect. For example, the following will not infer:"
+{ $example ": bad ( quot -- ) [ call ] keep foo ; inline recursive" "[ [ ] bad ] infer." "Literal value expected\n\nType :help for debugging help." }
+"The following is correct:"
+{ $example ": good ( quot: ( -- ) -- ) [ call ] keep good ; inline recursive" "[ [ ] good ] infer." "( -- )" }
+"An inline recursive word cannot pass a quotation on the data stack through the recursive call. For example, the following will not infer:"
+{ $example ": bad ( ? quot: ( ? -- ) -- ) 2dup [ not ] dip bad call ; inline recursive" "[ [ drop ] bad ] infer." "Literal value expected\n\nType :help for debugging help." }
 "However a small change can be made:"
-{ $example ": foo ( a b c -- d ) [ 2dup f foo drop ] when call ; inline" "[ 1 [ 1+ ] t foo ] infer." "( -- object )" }
+{ $example ": good ( ? quot: ( ? -- ) -- ) [ good ] 2keep [ not ] dip call ; inline recursive" "[ [ drop ] good ] infer." "( object -- )" }
 "An inline recursive word must have a fixed stack effect in its base case. The following will not infer:"
 { $code
     ": foo ( quot ? -- ) [ f foo ] [ call ] if ; inline"

core/assocs/assocs-docs.factor

@@ -21,7 +21,7 @@ ARTICLE: "enums" "Enumerations"
 { $subsection enum }
 { $subsection <enum> }
 "Inverting a permutation using enumerations:"
-{ $example "USING: assocs sorting prettyprint ;" ": invert <enum> >alist sort-values keys ;" "{ 2 0 4 1 3 } invert ." "{ 1 3 0 4 2 }" } ;
+{ $example "USING: assocs sorting prettyprint ;" "IN: scratchpad" ": invert ( perm -- perm' )" "    <enum> >alist sort-values keys ;" "{ 2 0 4 1 3 } invert ." "{ 1 3 0 4 2 }" } ;
 
 HELP: enum
 { $class-description "An associative structure which wraps a sequence and maps integers to the corresponding elements of the sequence."

core/classes/singleton/singleton-docs.factor

@@ -10,18 +10,6 @@ ARTICLE: "singletons" "Singleton classes"
 { $subsection singleton-class? }
 { $subsection singleton-class } ;
 
-HELP: SINGLETON:
-{ $syntax "SINGLETON: class" }
-{ $values
-    { "class" "a new singleton to define" }
-}
-{ $description
-    "Defines a new singleton class. The class word itself is the sole instance of the singleton class."
-}
-{ $examples
-    { $example "USING: classes.singleton kernel io ;" "IN: scratchpad" "SINGLETON: foo\nGENERIC: bar ( obj -- )\nM: foo bar drop \"a foo!\" print ;\nfoo bar" "a foo!" }
-} ;
-
 HELP: define-singleton-class
 { $values { "word" "a new word" } }
 { $description

core/kernel/kernel-docs.factor

@@ -888,9 +888,9 @@ $nl
 "Here is an array containing the " { $link f } " class:"
 { $example "{ POSTPONE: f } ." "{ POSTPONE: f }" }
 "The " { $link f } " object is an instance of the " { $link f } " class:"
-{ $example "f class ." "POSTPONE: f" }
+{ $example "USE: classes" "f class ." "POSTPONE: f" }
 "The " { $link f } " class is an instance of " { $link word } ":"
-{ $example "\\ f class ." "word" }
+{ $example "USE: classes" "\\ f class ." "word" }
 "On the other hand, " { $link t } " is just a word, and there is no class which it is a unique instance of."
 { $example "t \\ t eq? ." "t" }
 "Many words which search collections confuse the case of no element being present with an element being found equal to " { $link f } ". If this distinction is imporant, there is usually an alternative word which can be used; for example, compare " { $link at } " with " { $link at* } "." ;

core/math/integers/integers-docs.factor

@@ -4,10 +4,10 @@ IN: math.integers
 ARTICLE: "integers" "Integers"
 { $subsection integer }
 "Integers come in two varieties -- fixnums and bignums. Fixnums fit in a machine word and are faster to manipulate; if the result of a fixnum operation is too large to fit in a fixnum, the result is upgraded to a bignum. Here is an example where two fixnums are multiplied yielding a bignum:"
-{ $example "134217728 class ." "fixnum" }
-{ $example "128 class ." "fixnum" }
+{ $example "USE: classes" "134217728 class ." "fixnum" }
+{ $example "USE: classes" "128 class ." "fixnum" }
 { $example "134217728 128 * ." "17179869184" }
-{ $example "134217728 128 * class ." "bignum" }
+{ $example "USE: classes" "1 128 shift class ." "bignum" }
 "Integers can be entered using a different base; see " { $link "syntax-numbers" } "."
 $nl
 "Integers can be tested for, and real numbers can be converted to integers:"

core/math/math-docs.factor

@@ -321,8 +321,8 @@ ARTICLE: "number-protocol" "Number protocol"
 "Math operations obey certain numerical upgrade rules. If one of the inputs is a bignum and the other is a fixnum, the latter is first coerced to a bignum; if one of the inputs is a float, the other is coerced to a float."
 $nl
 "Two examples where you should note the types of the inputs and outputs:"
-{ $example "3 >fixnum 6 >bignum * class ." "bignum" }
-{ $example "1/2 2.0 + ." "4.5" }
+{ $example "USE: classes" "3 >fixnum 6 >bignum * class ." "bignum" }
+{ $example "1/2 2.0 + ." "2.5" }
 "The following usual operations are supported by all numbers."
 { $subsection + }
 { $subsection - }

core/syntax/syntax-docs.factor

@@ -352,6 +352,18 @@ HELP: SYMBOLS:
 { $description "Creates a new symbol for every token until the " { $snippet ";" } "." }
 { $examples { $example "USING: prettyprint ;" "IN: scratchpad" "SYMBOLS: foo bar baz ;\nfoo . bar . baz ." "foo\nbar\nbaz" } } ;
 
+HELP: SINGLETON:
+{ $syntax "SINGLETON: class" }
+{ $values
+    { "class" "a new singleton to define" }
+}
+{ $description
+    "Defines a new singleton class. The class word itself is the sole instance of the singleton class."
+}
+{ $examples
+    { $example "USING: classes.singleton kernel io ;" "IN: singleton-demo" "USE: prettyprint SINGLETON: foo\nGENERIC: bar ( obj -- )\nM: foo bar drop \"a foo!\" print ;\nfoo bar" "a foo!" }
+} ;
+    
 HELP: SINGLETONS:
 { $syntax "SINGLETONS: words... ;" }
 { $values { "words" "a sequence of new words to define" } }