diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 35 |
1 files changed, 29 insertions, 6 deletions
@@ -5858,25 +5858,48 @@ Dialect Note: A lambda expression is not a function name in TXR Lisp. The syntax (fun (lambda ...)) is invalid. -.SS Function symbol-function +.SS Functions symbol-function and symbol-value .TP Syntax: (symbol-function <symbol>) + (symbol-value <symbol>) .TP Description: -The symbol-function retrieves the toplevel function binding of the given -symbol if it has one. If the symbol has no toplevel function binding, -the value nil is returned. +The symbol-function retrieves the value of the toplevel function binding of the +given symbol if it has one: that is, the function object tied to the symbol. If +the symbol has no toplevel function binding, the value nil is returned. + +The symbol-value retrives the value of a toplevel variable, if it exists, +otherwise nil. .TP Dialect note: -The symbol-function form is currently not an assignable place. Only -the defun operator defines functions. +Forms which call symbol-function or symbol-value are currently not an +assignable place. Only the defun operator defines functions, and the set +operator modifies variables. There is no way to modify a toplevel variable that +is shadowed by a lexical variable. + +.SS Functions boundp and fboundp + +.TP +Syntax: + + (boundp <symbol>) + (fboundp <symbol>) + +.TP +Description: + +boundp returns t if the symbol has a variable binding in the toplevel +environment, otherwise nil. + +Foundp returns t if the symbol has a function binding in the toplevel +environment, or if it is an operator, otherwise nil. .SS Function func-get-form |