diff options
| -rw-r--r-- | lisplib.c | 2 | ||||
| -rw-r--r-- | share/txr/stdlib/ffi.tl | 3 | ||||
| -rw-r--r-- | txr.1 | 18 |
3 files changed, 21 insertions, 2 deletions
@@ -620,7 +620,7 @@ static val ffi_set_entries(val dlt, val fun) lit("deffi-sym"), lit("deffi-var"), lit("typedef"), lit("sizeof"), lit("alignof"), lit("offsetof"), lit("arraysize"), lit("elemsize"), lit("elemtype"), lit("ffi"), lit("carray-ref"), lit("carray-sub"), - lit("znew"), + lit("sub-buf"), lit("znew"), nil }; set_dlt_entries(dlt, name, fun); diff --git a/share/txr/stdlib/ffi.tl b/share/txr/stdlib/ffi.tl index 6bbd43a9..0bf111c0 100644 --- a/share/txr/stdlib/ffi.tl +++ b/share/txr/stdlib/ffi.tl @@ -148,6 +148,9 @@ (defset carray-sub (carray : (from 0) (to t)) items ^(progn (carray-replace ,carray ,items ,from ,to) ,items)) +(defset sub-buf (buf : (from 0) (to t)) items + ^(progn (replace-buf ,buf ,items ,from ,to) ,items)) + (defmacro znew (type . pairs) (if (oddp (length pairs)) (throwf 'eval-error "~s: slot initform arguments must occur pairwise" @@ -59655,9 +59655,10 @@ which has the same length and contents, and compares to .metn buf . -.coNP Function @ sub-buf +.coNP Accessor @ sub-buf .synb .mets (sub-buf < buf >> [ from <> [ to ]]) +.mets (set (sub-buf < buf >> [ from <> [ to ]]) << new-val ) .syne .desc The @@ -59668,6 +59669,21 @@ function, except that the first argument must be a buffer. The extracted sub-range of a buffer is itself a buffer object. +If +.code sub-buf +is used as a syntactic place, the argument expressions +.metn buf , +.metn from , +.meta to +and +.meta new-val +are evaluated just once. The prior value, if required, is accessed by calling +.code buf-sub +and +.meta new-val +is then stored via +.codn replace-buf . + .coNP Function @ replace-buf .synb .mets (replace-buf < buf < item-sequence >> [ from <> [ to ]]) |