diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 33 |
1 files changed, 28 insertions, 5 deletions
@@ -15077,7 +15077,7 @@ The entire lexical environment is copied; the copy and original function do not share any portion of the environment at any level of nesting. .SS* Sequencing, Selection and Iteration -.coNP Operators @ progn and @ prog1 +.coNP Operators/functions @ progn and @ prog1 .synb .mets (progn << form *) .mets (prog1 << form *) @@ -15110,12 +15110,26 @@ of a body of forms, the value of the last of which is returned. These operators are said to feature an implicit .codn progn . -.TP* "Dialect Note:" +These special operators are also functions. The +.code progn +function accepts zero or more arguments. It returns its last argument, or +.code nil +if called with no arguments. The +.code prog1 +function likewise accepts zero or more arguments. It returns its first argument, or +.code nil +if called with no arguments. + +.TP* "Dialect Notes:" In ANSI Common Lisp, .code prog1 -requires at least one argument. +requires at least one argument. Neither +.code prog +nor +.code prog1 +exist as functions. -.coNP Macro @ prog2 +.coNP Macro/function @ prog2 .synb .mets (prog2 << form *) .syne @@ -15142,10 +15156,19 @@ and yield .codn nil . -.TP* "Dialect Note:" +The +.code prog2 +symbol also has a function binding. The +.code prog2 +function accepts any number of arguments. If invoked with at least two arguments, +it returns the second one. Otherwise it returns +.codn nil . + +.TP* "Dialect Notes:" In ANSI Common Lisp, .code prog2 requires at least two arguments. +It does not exist as a function. .coNP Operator @ cond .synb |