diff options
Diffstat (limited to 'src/buffer.c')
| -rw-r--r-- | src/buffer.c | 75 |
1 files changed, 48 insertions, 27 deletions
diff --git a/src/buffer.c b/src/buffer.c index 20260d5a5d8..386d9a78153 100644 --- a/src/buffer.c +++ b/src/buffer.c @@ -933,6 +933,21 @@ If VARIABLE does not have a buffer-local binding in BUFFER, the value is the default binding of the variable. */) (register Lisp_Object variable, register Lisp_Object buffer) { + register Lisp_Object result = buffer_local_value_1 (variable, buffer); + + if (EQ (result, Qunbound)) + xsignal1 (Qvoid_variable, variable); + + return result; +} + + +/* Like Fbuffer_local_value, but return Qunbound if the variable is + locally unbound. */ + +Lisp_Object +buffer_local_value_1 (Lisp_Object variable, Lisp_Object buffer) +{ register struct buffer *buf; register Lisp_Object result; struct Lisp_Symbol *sym; @@ -985,10 +1000,7 @@ is the default binding of the variable. */) default: abort (); } - if (!EQ (result, Qunbound)) - return result; - - xsignal1 (Qvoid_variable, variable); + return result; } /* Return an alist of the Lisp-level buffer-local bindings of @@ -5329,31 +5341,40 @@ the mode line appears at the bottom. */); DEFVAR_PER_BUFFER ("mode-line-format", &BVAR (current_buffer, mode_line_format), Qnil, doc: /* Template for displaying mode line for current buffer. -Each buffer has its own value of this variable. -Value may be nil, a string, a symbol or a list or cons cell. + +The value may be nil, a string, a symbol or a list. + A value of nil means don't display a mode line. -For a symbol, its value is used (but it is ignored if t or nil). - A string appearing directly as the value of a symbol is processed verbatim - in that the %-constructs below are not recognized. - Note that unless the symbol is marked as a `risky-local-variable', all - properties in any strings, as well as all :eval and :propertize forms - in the value of that symbol will be ignored. -For a list of the form `(:eval FORM)', FORM is evaluated and the result - is used as a mode line element. Be careful--FORM should not load any files, - because that can cause an infinite recursion. -For a list of the form `(:propertize ELT PROPS...)', ELT is displayed - with the specified properties PROPS applied. -For a list whose car is a symbol, the symbol's value is taken, - and if that is non-nil, the cadr of the list is processed recursively. - Otherwise, the caddr of the list (if there is one) is processed. -For a list whose car is a string or list, each element is processed - recursively and the results are effectively concatenated. -For a list whose car is an integer, the cdr of the list is processed - and padded (if the number is positive) or truncated (if negative) - to the width specified by that number. + +For any symbol other than t or nil, the symbol's value is processed as + a mode line construct. As a special exception, if that value is a + string, the string is processed verbatim, without handling any + %-constructs (see below). Also, unless the symbol has a non-nil + `risky-local-variable' property, all properties in any strings, as + well as all :eval and :propertize forms in the value, are ignored. + +A list whose car is a string or list is processed by processing each + of the list elements recursively, as separate mode line constructs, + and concatenating the results. + +A list of the form `(:eval FORM)' is processed by evaluating FORM and + using the result as a mode line construct. Be careful--FORM should + not load any files, because that can cause an infinite recursion. + +A list of the form `(:propertize ELT PROPS...)' is processed by + processing ELT as the mode line construct, and adding the text + properties PROPS to the result. + +A list whose car is a symbol is processed by examining the symbol's + value, and, if that value is non-nil, processing the cadr of the list + recursively; and if that value is nil, processing the caddr of the + list recursively. + +A list whose car is an integer is processed by processing the cadr of + the list, and padding (if the number is positive) or truncating (if + negative) to the width specified by that number. + A string is printed verbatim in the mode line except for %-constructs: - (%-constructs are allowed when the string is the entire mode-line-format - or when it is found in a cons-cell or a list) %b -- print buffer name. %f -- print visited file name. %F -- print frame name. %* -- print %, * or hyphen. %+ -- print *, % or hyphen. |