diff options
Diffstat (limited to 'doc')
-rw-r--r-- | doc/manual/rl-next/env-size-reduction.md | 7 | ||||
-rw-r--r-- | doc/manual/rl-next/with-error-reporting.md | 31 |
2 files changed, 38 insertions, 0 deletions
diff --git a/doc/manual/rl-next/env-size-reduction.md b/doc/manual/rl-next/env-size-reduction.md new file mode 100644 index 000000000..40a58bc28 --- /dev/null +++ b/doc/manual/rl-next/env-size-reduction.md @@ -0,0 +1,7 @@ +--- +synopsis: Reduce eval memory usage and wall time +prs: 9658 +--- + +Reduce the size of the `Env` struct used in the evaluator by a pointer, or 8 bytes on most modern machines. +This reduces memory usage during eval by around 2% and wall time by around 3%. diff --git a/doc/manual/rl-next/with-error-reporting.md b/doc/manual/rl-next/with-error-reporting.md new file mode 100644 index 000000000..10b020956 --- /dev/null +++ b/doc/manual/rl-next/with-error-reporting.md @@ -0,0 +1,31 @@ +--- +synopsis: Better error reporting for `with` expressions +prs: 9658 +--- + +`with` expressions using non-attrset values to resolve variables are now reported with proper positions. + +Previously an incorrect `with` expression would report no position at all, making it hard to determine where the error originated: + +``` +nix-repl> with 1; a +error: + … <borked> + + at «none»:0: (source not available) + + error: value is an integer while a set was expected +``` + +Now position information is preserved and reported as with most other errors: + +``` +nix-repl> with 1; a +error: + … while evaluating the first subexpression of a with expression + at «string»:1:1: + 1| with 1; a + | ^ + + error: value is an integer while a set was expected +``` |