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author | Alan Mackenzie <acm@muc.de> | 2016-03-20 13:19:48 +0000 |
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committer | Alan Mackenzie <acm@muc.de> | 2016-03-20 13:19:48 +0000 |
commit | 9dcf5998935c8aaa846d7585b81f0dcfe1935b3d (patch) | |
tree | 371e627342a753acc111fa1c774cef559407e18f /doc/lispref/syntax.texi | |
parent | 565df7265dd73b4812fcb02cd1663fce4dc40be7 (diff) | |
download | emacs-9dcf5998935c8aaa846d7585b81f0dcfe1935b3d.tar.gz |
Amend parse-partial-sexp correctly to handle two character comment delimiters
Do this by adding a new field to the parser state: the syntax of the last
character scanned, should that be the first char of a (potential) two char
construct, nil otherwise.
This should make the parser state complete.
Also document element 9 of the parser state. Also refactor the code a bit.
* src/syntax.c (struct lisp_parse_state): Add a new field.
(SYNTAX_FLAGS_COMSTARTEND_FIRST): New function.
(internalize_parse_state): New function, extracted from scan_sexps_forward.
(back_comment): Call internalize_parse_state.
(forw_comment): Return the syntax of the last character scanned to the caller
when that character might be the first of a two character construct.
(Fforward_comment, scan_lists): New dummy variables, passed to forw_comment.
(scan_sexps_forward): Remove a redundant state parameter. Access all `state'
information via the address parameter `state'. Remove the code which converts
from external to internal form of `state'. Access buffer contents only from
`from' onwards. Reformulate code at the top of the main loop correctly to
recognize comment openers when starting in the middle of one. Call
forw_comment with extra argument (for return of syntax value of possible first
char of a two char construct).
(Fparse_partial_sexp): Document elements 9, 10 of the parser state in the
doc string. Clarify the doc string in general. Call
internalize_parse_state. Take account of the new elements when consing up the
output parser state.
* doc/lispref/syntax.texi: (Parser State): Document element 9 and the new
element 10. Minor wording corrections (remove reference to "trivial
cases").
(Low Level Parsing): Minor corrections.
* etc/NEWS: Note new element 10, and documentation of element 9 of parser
state.
Diffstat (limited to 'doc/lispref/syntax.texi')
-rw-r--r-- | doc/lispref/syntax.texi | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/doc/lispref/syntax.texi b/doc/lispref/syntax.texi index d5a7eba13fe..f81c1643c21 100644 --- a/doc/lispref/syntax.texi +++ b/doc/lispref/syntax.texi @@ -791,10 +791,10 @@ Hooks}). @subsection Parser State @cindex parser state - A @dfn{parser state} is a list of ten elements describing the state -of the syntactic parser, after it parses the text between a specified -starting point and a specified end point in the buffer. Parsing -functions such as @code{syntax-ppss} + A @dfn{parser state} is a list of (currently) eleven elements +describing the state of the syntactic parser, after it parses the text +between a specified starting point and a specified end point in the +buffer. Parsing functions such as @code{syntax-ppss} @ifnottex (@pxref{Position Parse}) @end ifnottex @@ -851,15 +851,20 @@ position where the string began. When outside of strings and comments, this element is @code{nil}. @item -Internal data for continuing the parsing. The meaning of this -data is subject to change; it is used if you pass this list -as the @var{state} argument to another call. +The list of the positions of the currently open parentheses, starting +with the outermost. + +@item +When the last buffer position scanned was the (potential) first +character of a two character construct (comment delimiter or +escaped/char-quoted character pair), the @var{syntax-code} +(@pxref{Syntax Table Internals}) of that position. Otherwise +@code{nil}. @end enumerate Elements 1, 2, and 6 are ignored in a state which you pass as an -argument to continue parsing, and elements 8 and 9 are used only in -trivial cases. Those elements are mainly used internally by the -parser code. +argument to continue parsing. Elements 9 and 10 are mainly used +internally by the parser code. One additional piece of useful information is available from a parser state using this function: @@ -898,11 +903,11 @@ The depth starts at 0, or at whatever is given in @var{state}. If the fourth argument @var{stop-before} is non-@code{nil}, parsing stops when it comes to any character that starts a sexp. If -@var{stop-comment} is non-@code{nil}, parsing stops when it comes to the -start of an unnested comment. If @var{stop-comment} is the symbol +@var{stop-comment} is non-@code{nil}, parsing stops after the start of +an unnested comment. If @var{stop-comment} is the symbol @code{syntax-table}, parsing stops after the start of an unnested -comment or a string, or the end of an unnested comment or a string, -whichever comes first. +comment or a string, or after the end of an unnested comment or a +string, whichever comes first. If @var{state} is @code{nil}, @var{start} is assumed to be at the top level of parenthesis structure, such as the beginning of a function |