instructionerrors.rs

use parity_wasm::elements::Instruction;
use std::error;
use std::fmt;

#[derive(Debug)]
pub enum InstructionError {
    GlobalNotFound,
    LocalNotFound,
    UnmatchedInstruction,
    InvalidOperation(Instruction),
}

impl fmt::Display for InstructionError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            InstructionError::GlobalNotFound => write!(f, "Global not found"),
            InstructionError::LocalNotFound => write!(f, "Local not found"),
            InstructionError::UnmatchedInstruction => write!(f, "Unmatched instruction"),
            InstructionError::InvalidOperation(i) => {
                write!(f, "{}", format!("Invalid operation: {:?}", i).as_str())
            }
        }
    }
}

impl error::Error for InstructionError {
    fn description(&self) -> &str {
        match self {
            InstructionError::GlobalNotFound => "Global not found",
            InstructionError::LocalNotFound => "Local not found",
            InstructionError::UnmatchedInstruction => "Unmatched instruction",
            InstructionError::InvalidOperation(_) => "Invalid operation",
        }
    }

    fn cause(&self) -> Option<&error::Error> {
        None
    }
}