sequences: define ?first and ?second.

[factor.git] / core / sequences / sequences-docs.factor

diff --git a/core/sequences/sequences-docs.factor b/core/sequences/sequences-docs.factor
index f9c390ee4964a89710b02cb111dc7379db60bb30..05365baf453461d43f876fa21a1868eeb0428a3c 100644 (file)
--- a/core/sequences/sequences-docs.factor
+++ b/core/sequences/sequences-docs.factor
@@ -179,6 +179,14 @@ HELP: ?nth
 { $values { "n" "an integer" } { "seq" sequence } { "elt/f" "an object or " { $link f } } }
 { $description "A forgiving version of " { $link nth } ". If the index is out of bounds, or if the sequence is " { $link f } ", simply outputs " { $link f } "." } ;
 
+HELP: ?first
+{ $values { "seq" sequence } { "elt/f" "an object or " { $link f } } }
+{ $description "A forgiving version of " { $link first } ". If the sequence is empty, or if the sequence is " { $link f } ", simply outputs " { $link f } "." } ;
+
+HELP: ?second
+{ $values { "seq" sequence } { "elt/f" "an object or " { $link f } } }
+{ $description "A forgiving version of " { $link second } ". If the sequence has less than two elements, or if the sequence is " { $link f } ", simply outputs " { $link f } "." } ;
+
 HELP: nth-unsafe
 { $values { "n" "an integer" } { "seq" sequence } { "elt" object } }
 { $contract "Unsafe variant of " { $link nth } " that does not perform bounds checks." } ;