Defaults the else clause to the identity filter "." if an else clause is
missing.
The following two jq programs are considered equivalent:
```
if .foo then
.foo = "bar"
else
.
end
```
```
if .foo then
.foo = "bar"
end
```
Attempting to use the existing FORK_OPT opcode resulted in difficulty
knowing when to pop an error message off the stack and when not to. This
commit makes DESTRUCTURE_ALT a real opcode that is identical to
FORK_OPT, except for never pushing the error message onto the stack when
continuing from an error backtrack.
Some small changes were necessary to the DUP/POP behavior surrounding
destructuring to accomodate this.
This reverts commit e24af3c78e.
While the semantics are desirable, there is no way to implement them
efficiently. The reason is that in order to handle backtracking (empty)
from the state update expression, we have to retain a reference to the
reduction state value in order to restore it upon backtracking.
Retaining a reference to the reduction state kills performance by
causing lots of additional memory allocations and garbage because the
input to the update expression will always have at least two references,
thus no changes to it can be done in-place, and all changes end up being
CoW changes.
Avoiding this is the very reason for the LOADVN instruction (leaving
`null` in the variable loaded from).
The conditional expression in if-then-elif-else-end cannot contribute to
path expressions because it doesn't change the input to any of the then/
elif/else expressions. These must be generated via gen_subexp().
See also #1366.
It needs to be possible to do something like
getpath($paths[]) += 1
meaning: increment all the paths in . that are listed in $paths[].
In order to do this getpath() needs to update the jq->path and
jq->value_at_path as necessary.
first(g) was extracting two values, which, if g is slow, made first(g)
slow. And if the second extraction were to throw an error, then
first(g) would throw that error, which is clearly not the right thing to
do. Besides that, first(g) was allocating garbage, which it no longer
does.
Use %%FAIL IGNORE MSG for error messages that differ on Windows, and
move the sort_by/group_by tests that fail qhen qsort() is not stable.
Now only tests/sorttest and tests/shtest are disabled on Windows.
This was an important conflict. In the following expression:
def a: 0; . | a
Bison needs to decide between these two equally valid
parses:
(def a: 0; .) | a
def a: 0; (. | a)
For jq we want the second one, because the first results in
"a/0 is not defined". In the current parser the first parse
is a reduce and the second parse is a shift. Since Bison
prefers to shift in shift/reduce conflicts, we accidentally
got the correct behavior.
This commit adds a precedence level FUNCDEF which is lower
precedence than '|', meaning we explicitly choose the
correct parse.
Of course many unit tests already cover this case, but I
added one specifically for it.
Muh Muhten
Chance Zibolski
Nicolas Williams
David Haguenauer
William Langford
pkoppstein
Shaun Guth
David Tolnay
Joel Nothman
Santiago Lapresta