Struct NixCExternalValueDesc

#[repr(C)]
pub struct NixCExternalValueDesc {
    pub print: Option<unsafe extern "C" fn(self_: *mut c_void, printer: *mut nix_printer)>,
    pub showType: Option<unsafe extern "C" fn(self_: *mut c_void, res: *mut nix_string_return)>,
    pub typeOf: Option<unsafe extern "C" fn(self_: *mut c_void, res: *mut nix_string_return)>,
    pub coerceToString: Option<unsafe extern "C" fn(self_: *mut c_void, c: *mut nix_string_context, coerceMore: c_int, copyToStore: c_int, res: *mut nix_string_return)>,
    pub equal: Option<unsafe extern "C" fn(self_: *mut c_void, other: *mut c_void) -> c_int>,
    pub printValueAsJSON: Option<unsafe extern "C" fn(self_: *mut c_void, state: *mut EvalState, strict: bool, c: *mut nix_string_context, copyToStore: bool, res: *mut nix_string_return)>,
    pub printValueAsXML: Option<unsafe extern "C" fn(self_: *mut c_void, state: *mut EvalState, strict: c_int, location: c_int, doc: *mut c_void, c: *mut nix_string_context, drvsSeen: *mut c_void, pos: c_int)>,
}

Definition for a class of external values Create and implement one of these, then pass it to nix_create_external_value Make sure to keep it alive while the external value lives. Optional functions can be set to NULL

See also

nix_create_external_value

Fields

print: Option<unsafe extern "C" fn(self_: *mut c_void, printer: *mut nix_printer)>

Called when printing the external value

Arguments

• self [in] - the void* passed to nix_create_external_value
• printer [out] - The printer to print to, pass to nix_external_print

showType: Option<unsafe extern "C" fn(self_: *mut c_void, res: *mut nix_string_return)>

Called on :t

Arguments

• self [in] - the void* passed to nix_create_external_value
• res [out] - the return value

typeOf: Option<unsafe extern "C" fn(self_: *mut c_void, res: *mut nix_string_return)>

Called on builtins.typeOf

Arguments

• self - the void* passed to nix_create_external_value
• res [out] - the return value

coerceToString: Option<unsafe extern "C" fn(self_: *mut c_void, c: *mut nix_string_context, coerceMore: c_int, copyToStore: c_int, res: *mut nix_string_return)>

Called on “${str}” and builtins.toString. The latter with coerceMore=true Optional, the default is to throw an error.

Arguments

• self [in] - the void* passed to nix_create_external_value
• c [out] - writable string context for the resulting string
• coerceMore [in] - boolean, try to coerce to strings in more cases instead of throwing an error
• copyToStore [in] - boolean, whether to copy referenced paths to store or keep them as-is
• res [out] - the return value. Not touching this, or setting it to the empty string, will make the conversion throw an error.

equal: Option<unsafe extern "C" fn(self_: *mut c_void, other: *mut c_void) -> c_int>

Try to compare two external values Optional, the default is always false. If the other object was not a Nix C external value, this comparison will also return false

Arguments

• self [in] - the void* passed to nix_create_external_value
• other [in] - the void* passed to the other object’s nix_create_external_value

Returns

true if the objects are deemed to be equal

printValueAsJSON: Option<unsafe extern "C" fn(self_: *mut c_void, state: *mut EvalState, strict: bool, c: *mut nix_string_context, copyToStore: bool, res: *mut nix_string_return)>

Convert the external value to json Optional, the default is to throw an error

Arguments

• self [in] - the void* passed to nix_create_external_value
• state [in] - The evaluator state
• strict [in] - boolean Whether to force the value before printing
• c [out] - writable string context for the resulting string
• copyToStore [in] - whether to copy referenced paths to store or keep them as-is
• res [out] - the return value. Gets parsed as JSON. Not touching this, or setting it to the empty string, will make the conversion throw an error.

printValueAsXML: Option<unsafe extern "C" fn(self_: *mut c_void, state: *mut EvalState, strict: c_int, location: c_int, doc: *mut c_void, c: *mut nix_string_context, drvsSeen: *mut c_void, pos: c_int)>

Convert the external value to XML Optional, the default is to throw an error @todo The mechanisms for this call are incomplete. There are no C bindings to work with XML, pathsets and positions.

Arguments

• self [in] - the void* passed to nix_create_external_value
• state [in] - The evaluator state
• strict [in] - boolean Whether to force the value before printing
• location [in] - boolean Whether to include position information in the xml
• doc [out] - XML document to output to
• c [out] - writable string context for the resulting string
• drvsSeen [in,out] - a path set to avoid duplicating derivations
• pos [in] - The position of the call.

Trait Implementations

impl Clone for NixCExternalValueDesc

fn clone(&self) -> NixCExternalValueDesc

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NixCExternalValueDesc

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for NixCExternalValueDesc