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authorFrancesco Potortì <pot@gnu.org>2002-07-02 11:54:32 +0000
committerFrancesco Potortì <pot@gnu.org>2002-07-02 11:54:32 +0000
commit1038941db1cf4c2345a7b2e5e1f6a182615bfa1a (patch)
tree69684192984fd5d40a38bce579ed7212708faa84 /etc/ETAGS.EBNF
parent005e1610198130bdca78577a3e9608716a4aac06 (diff)
downloademacs-1038941db1cf4c2345a7b2e5e1f6a182615bfa1a.tar.gz
Back to the old explanation, which was more concise, with just the first
two lines changed.
Diffstat (limited to 'etc/ETAGS.EBNF')
-rw-r--r--etc/ETAGS.EBNF24
1 files changed, 12 insertions, 12 deletions
diff --git a/etc/ETAGS.EBNF b/etc/ETAGS.EBNF
index d2f8b68297e..195eba67325 100644
--- a/etc/ETAGS.EBNF
+++ b/etc/ETAGS.EBNF
@@ -1,7 +1,9 @@
+-*- indented-text -*-
+
This file contains two sections:
1) An EBNF (Extended Backus Normal Form) description of the format of
- the tags file created by etags.c and interpreted by etags.el
+ the tags file created by etags.c and interpreted by etags.el
2) A discussion of tag names and implicit tag names
======================= EBNF tag file description =======================
@@ -56,7 +58,7 @@ realposition ::= "," unsint | unsint "," | unsint "," unsint
-======================== discussion on tag names =========================
+======================== discussion of tag names =========================
- What are tag names
Tag lines in a tags file are usually made from the above defined pattern
@@ -72,16 +74,14 @@ Emacs can find a tag faster and more accurately. These tag names are
part of tag lines in the tags file, so we call them "explicit".
- Why implicit tag names are even better
-Often tag names are redundant; this happens when the name of a tag is an
-easily guessable substring of the tag pattern. We define a set of rules
-to decide whether it is possible to deduce the tag name from the pattern,
-and make an unnamed tag in those cases. The name deduced from the
-pattern of an unnamed tag is the implicit name of that tag. The use of
-implicit tag names reduces the size of the tags file. When the user
-looks for a tag, and Emacs founds no explicit tag names that match it,
-Emacs then tries to match the tag with an implicit tag name. Such a
-match occurs when the tag matches a pattern, subject to the satisfaction
-of all the following four rules:
+When a tag line has no name, but a name can be deduced from the pattern,
+we say that the tag line has an implicit tag name. etags.c uses
+implicit tag names when possible, in order to reduce the number of
+explicit tag names in a tags file, thus reducing the size of the tags
+file. When the user looks for a tag, and Emacs founds no explicit tag
+names that match it, Emacs then tries to match the tag with an implicit
+tag name. Such a match occurs when the tag matches a pattern, subject
+to the satisfaction of all the following four rules:
NONAM=" \f\t\n\r()=,;";
1. the tag does not contain any of the characters in NONAM;