Attachment "Tcl.n.patch" to
ticket [827119ffff]
added by
msofer
2003-10-26 06:21:00.
Index: doc/Tcl.n
===================================================================
RCS file: /cvsroot/tcl/tcl/doc/Tcl.n,v
retrieving revision 1.9
diff -u -r1.9 Tcl.n
--- doc/Tcl.n 1 Feb 2003 19:48:23 -0000 1.9
+++ doc/Tcl.n 25 Oct 2003 23:16:46 -0000
@@ -49,8 +49,17 @@
Command substitution, variable substitution, and backslash substitution
are performed on the characters between the quotes as described below.
The double-quotes are not retained as part of the word.
-.IP "[5] \fBBraces.\fR"
-If the first character of a word is an open brace (``{'') then
+.IP "[5] \fBArgument expansion.\fR"
+If a word starts with the string ``{expand}'' followed by a
+non-whitespace character, then the leading ``{expand}'' is removed
+and the rest of the word is parsed and substituted as any other other
+word. After substitution, the word is parsed again without
+substitutions, and its words are added to the command being
+substituted. For instance, ``cmd a {expand}{b c} d {expand}{e f}'' is
+equivalent to ``cmd a b c d e f''.
+.IP "[6] \fBBraces.\fR"
+If the first character of a word is an open brace (``{'') and
+rule [5] does not apply, then
the word is terminated by the matching close brace (``}'').
Braces nest within the word: for each additional open
brace there must be an additional close brace (however,
@@ -63,7 +72,7 @@
or white space receive any special interpretation.
The word will consist of exactly the characters between the
outer braces, not including the braces themselves.
-.IP "[6] \fBCommand substitution.\fR"
+.IP "[7] \fBCommand substitution.\fR"
If a word contains an open bracket (``['') then Tcl performs
\fIcommand substitution\fR.
To do this it invokes the Tcl interpreter recursively to process
@@ -75,7 +84,7 @@
characters between them.
There may be any number of command substitutions in a single word.
Command substitution is not performed on words enclosed in braces.
-.IP "[7] \fBVariable substitution.\fR"
+.IP "[8] \fBVariable substitution.\fR"
If a word contains a dollar-sign (``$'') then Tcl performs \fIvariable
substitution\fR: the dollar-sign and the following characters are
replaced in the word by the value of a variable.
@@ -102,7 +111,7 @@
There may be any number of variable substitutions in a single word.
Variable substitution is not performed on words enclosed in braces.
.RE
-.IP "[8] \fBBackslash substitution.\fR"
+.IP "[9] \fBBackslash substitution.\fR"
If a backslash (``\e'') appears within a word then
\fIbackslash substitution\fR occurs.
In all cases but those described below the backslash is dropped and
@@ -173,14 +182,14 @@
Backslash substitution is not performed on words enclosed in braces,
except for backslash-newline as described above.
.RE
-.IP "[9] \fBComments.\fR"
+.IP "[10] \fBComments.\fR"
If a hash character (``#'') appears at a point where Tcl is
expecting the first character of the first word of a command,
then the hash character and the characters that follow it, up
through the next newline, are treated as a comment and ignored.
The comment character only has significance when it appears
at the beginning of a command.
-.IP "[10] \fBOrder of substitution.\fR"
+.IP "[11] \fBOrder of substitution.\fR"
Each character is processed exactly once by the Tcl interpreter
as part of creating the words of a command.
For example, if variable substitution occurs then no further
@@ -201,8 +210,9 @@
.CE
will always set the variable \fIy\fR to the value, \fI012\fR.
.RE
-.IP "[11] \fBSubstitution and word boundaries.\fR"
-Substitutions do not affect the word boundaries of a command.
+.IP "[12] \fBSubstitution and word boundaries.\fR"
+Substitutions do not affect the word boundaries of a command,
+except for argument expansion as specified in rule [5].
For example, during variable substitution the entire value of
the variable becomes part of a single word, even if the variable's
value contains spaces.
