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author | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2012-08-13T05·53-0400 |
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committer | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2012-08-13T05·53-0400 |
commit | 198d0338be7c105b6dbd707f98e0c223a8358240 (patch) | |
tree | 60653ffc15a4579bd21fa1057abe7cdefaa94d89 /src/nix-setuid-helper/nix-setuid-helper.cc | |
parent | b9e5b908ed29bfb6cd82837f9f57293c1f63e999 (diff) |
Add a primop ‘concatLists’
This can serve as a generic efficient list builder. For instance, the function ‘catAttrs’ in Nixpkgs can be rewritten from attr: l: fold (s: l: if hasAttr attr s then [(getAttr attr s)] ++ l else l) [] l to attr: l: builtins.concatLists (map (s: if hasAttr attr s then [(getAttr attr s)] else []) l) Statistics before: time elapsed: 1.08683 size of a value: 24 environments allocated: 1384376 (35809568 bytes) list elements: 6946783 (55574264 bytes) list concatenations: 37434 values allocated: 1760440 (42250560 bytes) attribute sets allocated: 392040 right-biased unions: 186334 values copied in right-biased unions: 591137 symbols in symbol table: 18273 number of thunks: 1297673 number of thunks avoided: 1380759 number of attr lookups: 430802 number of primop calls: 628912 number of function calls: 1333544 Statistics after (including new catAttrs): time elapsed: 0.959854 size of a value: 24 environments allocated: 1010198 (26829296 bytes) list elements: 1984878 (15879024 bytes) list concatenations: 30488 values allocated: 1589760 (38154240 bytes) attribute sets allocated: 392040 right-biased unions: 186334 values copied in right-biased unions: 591137 symbols in symbol table: 18274 number of thunks: 1040925 number of thunks avoided: 1038428 number of attr lookups: 438419 number of primop calls: 474844 number of function calls: 959366
Diffstat (limited to 'src/nix-setuid-helper/nix-setuid-helper.cc')
0 files changed, 0 insertions, 0 deletions