Struct Matcher 

pub struct Matcher<'a, Call> { /* private fields */ }

Struct created from calling fn matcher() on a mutable slice of Instructions.

Implements MatchXcm to allow an iterator-like API to match against each Instruction contained within the slice, which facilitates the building of XCM barriers.

Trait Implementations

impl<'a, Call> MatchXcm for Matcher<'a, Call>

type Error = ProcessMessageError

The error type to throw when errors happen during matching.

type Inst = Instruction<Call>

The concrete instruction type. Necessary to specify as it changes between XCM versions.

type Loc = Location

The Location type. Necessary to specify as it changes between XCM versions.

fn assert_remaining_insts(self, n: usize) -> Result<Self, Self::Error>

where Self: Sized,

Returns success if the number of instructions that still have not been iterated over equals n, otherwise returns an error.

fn match_next_inst<F>(self, f: F) -> Result<Self, Self::Error>

where Self: Sized, F: FnMut(&mut Self::Inst) -> Result<(), Self::Error>,

Accepts a closure f that contains an argument signifying the next instruction to be iterated over. The closure can then be used to check whether the instruction matches a given condition, and can also be used to mutate the fields of an instruction.

fn match_next_inst_while<C, F>(self, cond: C, f: F) -> Result<Self, Self::Error>

where Self: Sized, C: Fn(&Self::Inst) -> bool, F: FnMut(&mut Self::Inst) -> Result<ControlFlow<()>, Self::Error>,

Attempts to continuously iterate through the instructions while applying f to each of them, until either the last instruction or cond returns false.

fn skip_inst_while<C>(self, cond: C) -> Result<Self, Self::Error>

where Self: Sized, C: Fn(&Self::Inst) -> bool,

Iterate instructions forward until cond returns false. When there are no more instructions to be read, an error is returned.