diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 53 |
1 files changed, 47 insertions, 6 deletions
@@ -9086,7 +9086,10 @@ is also the empty list, which terminates nonempty lists. similarly to Common Lisp, including the convention that .code defvar marks symbols for dynamic binding in local scopes. Lexical closures -are supported. Functions are lexically scoped in \*(TL; they can be +are supported. \*(TL also supports global lexical variables via +.codn defvarl . + +Functions are lexically scoped in \*(TL; they can be defined in pervasive global environment using .code defun or in local scopes using @@ -10429,14 +10432,12 @@ a form are fully expanded prior to the evaluation of a form, therefore evaluation does not consider the possibility of a symbol being a symbol macro. -.coNP Operators @ defvar and @ defparm +.coNP Operator @ defvar and macro @ defparm .synb .mets (defvar < sym <> [ value ]) .mets (defparm < sym << value ) .syne - .desc - The .code defvar operator binds a name in the variable namespace of the global environment. @@ -10488,7 +10489,7 @@ above. The .code defparm -operator behaves like +macro behaves like .code defvar when a variable named .meta sym @@ -10512,9 +10513,49 @@ The .code defvar and .code defparm -operators return +forms return .metn sym . +.coNP Macros @ defvarl and @ defparml +.synb +.mets (defvarl < sym <> [ value ]) +.mets (defparml < sym << value ) +.syne +.desc +The +.code defvarl +and +.code defparml +macros behave, respectively, almost exactly like +.code defvar +and +.codn defparm . + +The difference is that these operators do not mark +.meta sym +as special. + +If a global variable +.meta sym +does not previously exist, then after the evaluation of +either of these forms +.cblk +.meti (boundp << sym ) +.cble +is true, but +.cblk +.meti (special-var-p << sym ) +.cble +isn't. + +If +.meta sym +had been already introduced as a special variable, it stays that way +after the evaluation of +.code defvarl +or +.codn defparml . + .coNP Operators @ let and @ let* .synb .mets (let >> ({ sym | >> ( sym << init-form )}*) << body-form *) |