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diff --git a/nocopy-doc.diff b/nocopy-doc.diff deleted file mode 100644 index bc63cff3..00000000 --- a/nocopy-doc.diff +++ /dev/null @@ -1,238 +0,0 @@ -diff --git a/doc/gawktexi.in b/doc/gawktexi.in -index efca7b6..76c3a9b 100644 ---- a/doc/gawktexi.in -+++ b/doc/gawktexi.in -@@ -11527,17 +11527,93 @@ compares variables. - @node Variable Typing - @subsubsection String Type versus Numeric Type - -+Scalar objects in @command{awk} (variables, array elements, and fields) -+are @emph{dynamically} typed. This means their type can change as the -+program runs, from @dfn{untyped} before any use,@footnote{@command{gawk} -+calls this @dfn{unassigned}, as the following example shows.} to string -+or number, and then from string to number or number to string, as the -+program progresses. -+ -+You can't do much with untyped variables, other than tell that they -+are untyped. The following program tests @code{a} against @code{""} -+and @code{0}; the test succeeds when @code{a} has never been assigned -+a value. It also uses the built-in @code{typeof()} function -+(not presented yet; @pxref{Type Functions}) to show @code{a}'s type: -+ -+@example -+$ @kbd{gawk 'BEGIN @{ print (a == "" && a == 0 ?} -+> @kbd{"a is untyped" : "a has a type!") ; print typeof(a) @}'} -+@print{} a is untyped -+@print{} unassigned -+@end example -+ -+A scalar has numeric type when assigned a numeric value, -+such as from a numeric constant, or from another scalar -+with numeric type: -+ -+@example -+$ @kbd{gawk 'BEGIN @{ a = 42 ; print typeof(a)} -+> @kbd{b = a ; print typeof(b) @}'} -+number -+number -+@end example -+ -+Similarly, a scalar has string type when assigned a string -+value, such as from a string constant, or from another scalar -+with string type: -+ -+@example -+$ @kbd{gawk 'BEGIN @{ a = "forty two" ; print typeof(a)} -+> @kbd{b = a ; print typeof(b) @}'} -+string -+string -+@end example -+ -+So far, this is all simple and straightforward. What happens, though, -+when @command{awk} has to process data from a user? Let's start with -+field data. What should the following command produce as output? -+ -+@example -+echo hello | awk '@{ printf("%s %s < 42\n", $1, -+ ($1 < 42 ? "is" : "is not")) @}' -+@end example -+ -+@noindent -+Since @samp{hello} is alphabetic data, @command{awk} can only do a string -+comparison. Internally, it converts @code{42} into @code{"42"} and compares -+the two string values @code{"hello"} and @code{"42"}. Here's the result: -+ -+@example -+$ @kbd{echo hello | awk '@{ printf("%s %s < 42\n", $1,} -+> @kbd{ ($1 < 42 ? "is" : "is not")) @}'} -+@print{} hello is not < 42 -+@end example -+ -+However, what happens when data from a user @emph{looks like} a number? -+On the one hand, in reality, the input data consists of characters, not -+binary numeric -+values. But, on the other hand, the data looks numeric, and @command{awk} -+really ought to treat it as such. And indeed, it does: -+ -+@example -+$ @kbd{echo 37 | awk '@{ printf("%s %s < 42\n", $1,} -+> @kbd{ ($1 < 42 ? "is" : "is not")) @}'} -+@print{} 37 is < 42 -+@end example -+ -+Here are the rules for when @command{awk} -+treats data as a number, and for when it treats data as a string. -+ - @cindex numeric, strings - @cindex strings, numeric - @cindex POSIX @command{awk}, numeric strings and --The POSIX standard introduced --the concept of a @dfn{numeric string}, which is simply a string that looks --like a number---for example, @code{@w{" +2"}}. This concept is used --for determining the type of a variable. --The type of the variable is important because the types of two variables --determine how they are compared. --Variable typing follows these rules: -+The POSIX standard uses the term @dfn{numeric string} for input data that -+looks numeric. The @samp{37} in the previous example is a numeric string. -+So what is the type of a numeric string? Answer: numeric. - -+The type of a variable is important because the types of two variables -+determine how they are compared. -+Variable typing follows these definitions and rules: - - @itemize @value{BULLET} - @item -@@ -11552,7 +11628,9 @@ attribute. - Fields, @code{getline} input, @code{FILENAME}, @code{ARGV} elements, - @code{ENVIRON} elements, and the elements of an array created by - @code{match()}, @code{split()}, and @code{patsplit()} that are numeric --strings have the @dfn{strnum} attribute. Otherwise, they have -+strings have the @dfn{strnum} attribute.@footnote{Thus, a POSIX -+numeric string and @command{gawk}'s strnum are the same thing.} -+Otherwise, they have - the @dfn{string} attribute. Uninitialized variables also have the - @dfn{strnum} attribute. - -@@ -11626,7 +11704,7 @@ STRNUM &&string &numeric &numeric\cr - @end tex - @ifnottex - @ifnotdocbook --@display -+@verbatim - +---------------------------------------------- - | STRING NUMERIC STRNUM - --------+---------------------------------------------- -@@ -11637,7 +11715,7 @@ NUMERIC | string numeric numeric - | - STRNUM | string numeric numeric - --------+---------------------------------------------- --@end display -+@end verbatim - @end ifnotdocbook - @end ifnottex - @docbook -@@ -11696,10 +11774,14 @@ purposes. - In short, when one operand is a ``pure'' string, such as a string - constant, then a string comparison is performed. Otherwise, a - numeric comparison is performed. -+(The primary difference between a number and a strnum is that -+for strnums @command{gawk} preserves the original string value that -+the scalar had when it came in.) -+ -+This point bears additional emphasis: -+Input that looks numeric @emph{is} numeric. -+All other input is treated as strings. - --This point bears additional emphasis: All user input is made of characters, --and so is first and foremost of string type; input strings --that look numeric are additionally given the strnum attribute. - Thus, the six-character input string @w{@samp{ +3.14}} receives the - strnum attribute. In contrast, the eight characters - @w{@code{" +3.14"}} appearing in program text comprise a string constant. -@@ -11726,6 +11808,14 @@ $ @kbd{echo ' +3.14' | awk '@{ print($1 == 3.14) @}'} @ii{True} - @print{} 1 - @end example - -+You can see the type of an input field (or other user input) -+using @code{typeof()}: -+ -+@example -+$ @kbd{echo hello 37 | gawk '@{ print typeof($1), typeof($2) @}'} -+@print{} string strnum -+@end example -+ - @node Comparison Operators - @subsubsection Comparison Operators - -@@ -18688,8 +18778,8 @@ Return one of the following strings, depending upon the type of @var{x}: - @var{x} is a string. - - @item "strnum" --@var{x} is a string that might be a number, such as a field or --the result of calling @code{split()}. (I.e., @var{x} has the STRNUM -+@var{x} is a number that started life as user input, such as a field or -+the result of calling @code{split()}. (I.e., @var{x} has the strnum - attribute; @pxref{Variable Typing}.) - - @item "unassigned" -@@ -18698,8 +18788,9 @@ For example: - - @example - BEGIN @{ -- a[1] # creates a[1] but it has no assigned value -- print typeof(a[1]) # scalar_u -+ # creates a[1] but it has no assigned value -+ a[1] -+ print typeof(a[1]) # unassigned - @} - @end example - -@@ -29721,6 +29812,8 @@ executing, short programs. - The @command{gawk} debugger only accepts source code supplied with the @option{-f} option. - @end itemize - -+@ignore -+@c 11/2016: This no longer applies after all the type cleanup work that's been done. - One other point is worth discussing. Conventional debuggers run in a - separate process (and thus address space) from the programs that they - debug (the @dfn{debuggee}, if you will). -@@ -29779,6 +29872,7 @@ is indeed a number, and this is reflected in the result of - Cases like this where the debugger is not transparent to the program's - execution should be rare. If you encounter one, please report it - (@pxref{Bugs}). -+@end ignore - - @ignore - Look forward to a future release when these and other missing features may -@@ -31285,14 +31379,26 @@ and is managed by @command{gawk} from then on. - The API defines several simple @code{struct}s that map values as seen - from @command{awk}. A value can be a @code{double}, a string, or an - array (as in multidimensional arrays, or when creating a new array). -+ - String values maintain both pointer and length, because embedded @sc{nul} - characters are allowed. - - @quotation NOTE --By intent, strings are maintained using the current multibyte encoding (as --defined by @env{LC_@var{xxx}} environment variables) and not using wide --characters. This matches how @command{gawk} stores strings internally --and also how characters are likely to be input into and output from files. -+By intent, @command{gawk} maintains strings using the current multibyte -+encoding (as defined by @env{LC_@var{xxx}} environment variables) -+and not using wide characters. This matches how @command{gawk} stores -+strings internally and also how characters are likely to be input into -+and output from files. -+@end quotation -+ -+@quotation NOTE -+String values passed to an extension by @command{gawk} are always -+@sc{NUL}-terminated. Thus it is safe to pass such string values to -+standard library and system routines. However, because -+@command{gawk} allows embedded @sc{NUL} characters in string data, -+you should check that @samp{strlen(@var{some_string})} matches -+the length for that string passed to the extension before using -+it as a regular C string. - @end quotation - - @item |