mirror of
https://github.com/NixOS/nix.git
synced 2024-11-26 00:32:28 +00:00
Document some primops
This commit is contained in:
Eelco Dolstra
parent
24b1c2c66b
commit
b8416779e3
@ -1053,7 +1053,7 @@ static RegisterPrimOp primop_toPath({
|
||||
.name = "__toPath",
|
||||
.args = {"s"},
|
||||
.doc = R"(
|
||||
DEPRECATED. Use `/. + "/path"` to convert a string into an absolute
|
||||
**DEPRECATED.** Use `/. + "/path"` to convert a string into an absolute
|
||||
path. For relative paths, use `./. + "/path"`.
|
||||
)",
|
||||
.fun = prim_toPath,
|
||||
@ -1090,6 +1090,23 @@ static void prim_storePath(EvalState & state, const Pos & pos, Value * * args, V
|
||||
mkString(v, path, context);
|
||||
}
|
||||
|
||||
static RegisterPrimOp primop_storePath({
|
||||
.name = "__storePath",
|
||||
.args = {"path"},
|
||||
.doc = R"(
|
||||
This function allows you to define a dependency on an already
|
||||
existing store path. For example, the derivation attribute `src
|
||||
= builtins.storePath /nix/store/f1d18v1y…-source` causes the
|
||||
derivation to depend on the specified path, which must exist or
|
||||
be substitutable. Note that this differs from a plain path
|
||||
(e.g. `src = /nix/store/f1d18v1y…-source`) in that the latter
|
||||
causes the path to be *copied* again to the Nix store, resulting
|
||||
in a new path (e.g. `/nix/store/ld01dnzc…-source-source`).
|
||||
|
||||
This function is not available in pure evaluation mode.
|
||||
)",
|
||||
.fun = prim_storePath,
|
||||
});
|
||||
|
||||
static void prim_pathExists(EvalState & state, const Pos & pos, Value * * args, Value & v)
|
||||
{
|
||||
@ -2022,9 +2039,6 @@ static RegisterPrimOp primop_listToAttrs({
|
||||
.fun = prim_listToAttrs,
|
||||
});
|
||||
|
||||
/* Return the right-biased intersection of two sets as1 and as2,
|
||||
i.e. a set that contains every attribute from as2 that is also a
|
||||
member of as1. */
|
||||
static void prim_intersectAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
|
||||
{
|
||||
state.forceAttrs(*args[0], pos);
|
||||
@ -2049,13 +2063,6 @@ static RegisterPrimOp primop_intersectAttrs({
|
||||
.fun = prim_intersectAttrs,
|
||||
});
|
||||
|
||||
/* Collect each attribute named `attr' from a list of attribute sets.
|
||||
Sets that don't contain the named attribute are ignored.
|
||||
|
||||
Example:
|
||||
catAttrs "a" [{a = 1;} {b = 0;} {a = 2;}]
|
||||
=> [1 2]
|
||||
*/
|
||||
static void prim_catAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
|
||||
{
|
||||
Symbol attrName = state.symbols.create(state.forceStringNoCtx(*args[0], pos));
|
||||
@ -2077,19 +2084,23 @@ static void prim_catAttrs(EvalState & state, const Pos & pos, Value * * args, Va
|
||||
v.listElems()[n] = res[n];
|
||||
}
|
||||
|
||||
/* Return a set containing the names of the formal arguments expected
|
||||
by the function `f'. The value of each attribute is a Boolean
|
||||
denoting whether the corresponding argument has a default value. For instance,
|
||||
static RegisterPrimOp primop_catAttrs({
|
||||
.name = "__catAttrs",
|
||||
.args = {"attr", "list"},
|
||||
.doc = R"(
|
||||
Collect each attribute named *attr* from a list of attribute
|
||||
sets. Attrsets that don't contain the named attribute are
|
||||
ignored. For example,
|
||||
|
||||
functionArgs ({ x, y ? 123}: ...)
|
||||
=> { x = false; y = true; }
|
||||
```nix
|
||||
builtins.catAttrs "a" [{a = 1;} {b = 0;} {a = 2;}]
|
||||
```
|
||||
|
||||
"Formal argument" here refers to the attributes pattern-matched by
|
||||
the function. Plain lambdas are not included, e.g.
|
||||
evaluates to `[1 2]`.
|
||||
)",
|
||||
.fun = prim_catAttrs,
|
||||
});
|
||||
|
||||
functionArgs (x: ...)
|
||||
=> { }
|
||||
*/
|
||||
static void prim_functionArgs(EvalState & state, const Pos & pos, Value * * args, Value & v)
|
||||
{
|
||||
state.forceValue(*args[0], pos);
|
||||
@ -2131,7 +2142,7 @@ static RegisterPrimOp primop_functionArgs({
|
||||
.fun = prim_functionArgs,
|
||||
});
|
||||
|
||||
/* Apply a function to every element of an attribute set. */
|
||||
/* */
|
||||
static void prim_mapAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
|
||||
{
|
||||
state.forceAttrs(*args[1], pos);
|
||||
@ -2147,6 +2158,21 @@ static void prim_mapAttrs(EvalState & state, const Pos & pos, Value * * args, Va
|
||||
}
|
||||
}
|
||||
|
||||
static RegisterPrimOp primop_mapAttrs({
|
||||
.name = "__mapAttrs",
|
||||
.args = {"f", "attrset"},
|
||||
.doc = R"(
|
||||
Apply function *f* to every element of *attrset*. For example,
|
||||
|
||||
```nix
|
||||
builtins.mapAttrs (name: value: value * 10) { a = 1; b = 2; }
|
||||
```
|
||||
|
||||
evaluates to `{ a = 10; b = 20; }`.
|
||||
)",
|
||||
.fun = prim_mapAttrs,
|
||||
});
|
||||
|
||||
|
||||
/*************************************************************
|
||||
* Lists
|
||||
@ -2582,9 +2608,29 @@ static void prim_partition(EvalState & state, const Pos & pos, Value * * args, V
|
||||
v.attrs->sort();
|
||||
}
|
||||
|
||||
static RegisterPrimOp primop_partition({
|
||||
.name = "__partition",
|
||||
.args = {"pred", "list"},
|
||||
.doc = R"(
|
||||
Given a predicate function *pred*, this function returns an
|
||||
attrset containing a list named `right`, containing the elements
|
||||
in *list* for which *pred* returned `true`, and a list named
|
||||
`wrong`, containing the elements for which it returned
|
||||
`false`. For example,
|
||||
|
||||
```nix
|
||||
builtins.partition (x: x > 10) [1 23 9 3 42]
|
||||
```
|
||||
|
||||
evaluates to
|
||||
|
||||
```nix
|
||||
{ right = [ 23 42 ]; wrong = [ 1 9 3 ]; }
|
||||
```
|
||||
)",
|
||||
.fun = prim_partition,
|
||||
});
|
||||
|
||||
/* concatMap = f: list: concatLists (map f list); */
|
||||
/* C++-version is to avoid allocating `mkApp', call `f' eagerly */
|
||||
static void prim_concatMap(EvalState & state, const Pos & pos, Value * * args, Value & v)
|
||||
{
|
||||
state.forceFunction(*args[0], pos);
|
||||
@ -2611,6 +2657,16 @@ static void prim_concatMap(EvalState & state, const Pos & pos, Value * * args, V
|
||||
}
|
||||
}
|
||||
|
||||
static RegisterPrimOp primop_concatMap({
|
||||
.name = "__concatMap",
|
||||
.args = {"f", "list"},
|
||||
.doc = R"(
|
||||
This function is equivalent to `builtins.concatLists (map f list)`
|
||||
but is more efficient.
|
||||
)",
|
||||
.fun = prim_concatMap,
|
||||
});
|
||||
|
||||
|
||||
/*************************************************************
|
||||
* Integer arithmetic
|
||||
@ -3361,17 +3417,10 @@ void EvalState::createBaseEnv()
|
||||
addPrimOp("__addErrorContext", 2, prim_addErrorContext);
|
||||
|
||||
// Paths
|
||||
addPrimOp("__storePath", 1, prim_storePath);
|
||||
addPrimOp("__findFile", 2, prim_findFile);
|
||||
|
||||
// Sets
|
||||
addPrimOp("__unsafeGetAttrPos", 2, prim_unsafeGetAttrPos);
|
||||
addPrimOp("__catAttrs", 2, prim_catAttrs);
|
||||
addPrimOp("__mapAttrs", 2, prim_mapAttrs);
|
||||
|
||||
// Lists
|
||||
addPrimOp("__partition", 2, prim_partition);
|
||||
addPrimOp("__concatMap", 2, prim_concatMap);
|
||||
|
||||
// Derivations
|
||||
addPrimOp("derivationStrict", 1, prim_derivationStrict);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user