diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 37 |
1 files changed, 36 insertions, 1 deletions
@@ -17747,6 +17747,24 @@ are enclosed in an implicit anonymous block. If the forms terminate by returning from the anonymous block then these macros terminate with the specified value. +When +.code sum-each* +and +.code sum-each +are specified with variables whose values specify zero iterations, +or with no variables at all, the form terminates with a value of +.codn 0 . +In this situation, +.code mul-each +and +.code mul-each* +terminate with +.codn 1 . +Note that this behavior differs from +.codn each , +and its closely-related operators, which loop infinitely when no variables are +specified. + .coNP Macros @, each-prod @ collect-each-prod and @ append-each-prod .synb .mets (each-prod >> ({( sym << init-form )}*) << body-form *) @@ -17782,6 +17800,14 @@ operator family, the are surrounded by an anonymous block. If these forms execute a return from this block, then these macros terminate with the specified return value. +When no iterations are performed, including in the case when an empty +list of variables is specified, all these macro forms terminate and return +.codn nil . +Note that this behavior differs from +.codn each , +and its closely-related operators, which loop infinitely when no variables are +specified. + With one caveat noted below, these macros can be understood as providing syntactic sugar according to the pattern established by the following equivalences: @@ -17799,7 +17825,6 @@ equivalences: body) body) #:gx #:gy)) - (append-each-prod (block nil ((x xinit) (let ((#:gx xinit) (#:gy yinit)) (y yinit)) <--> (maprend (lambda (x y) @@ -17914,6 +17939,16 @@ The are surrounded by an implicit anonymous block. If these forms execute a return from this block, then these macros terminate with the specified return value. +When no iterations are specified, including in the case when an empty +list of variables is specified, the summing macros terminate, yielding +.codn 0 , +and the multiplicative macros terminate with +.codn 1 . +Note that this behavior differs from +.codn each , +and its closely-related operators, which loop infinitely when no variables are +specified. + .TP* Examples: .verb |