gestionar errores en funciones, como añadir información contextual a los errores. use anyhow::{bail, Context, Result}; use std::fs; use std::io::Read; use thiserror::Error; struct EmptyUsernameError(String); String::with_capacity(100); fs::File::open(path) .with_context(|| format!("No se ha podido abrir {path}"))? .read_to_string(&mut username) .context("No se ha podido leer")?; if username.is_empty() { bail error) de Go. • anyhow::Context es un trait implementado para los tipos estándar Result y Option. Se necesita use anyhow::Context para habilitar .context() y .with_context() en esos tipos. 29.7 Ejercicio:

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant mensajes. @startuml autonumber Bob -> Alice : Authentication Request Bob <- Alice : Authentication Response @enduml Guía de Referencia del Lenguaje PlantUML (1.2019.1) 4 / 146 1.7 Numeración de la secuencia

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible have a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant mensajes. @startuml autonumber Bob -> Alice : Authentication Request Bob <- Alice : Authentication Response @enduml Guía de Referencia del Lenguaje PlantUML (1.2019.4) 4 / 165 1.7 Numeración de la secuencia

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible have a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant mensajes. @startuml autonumber Bob -> Alice : Authentication Request Bob <- Alice : Authentication Response @enduml Guía de Referencia del Lenguaje PlantUML (1.2019.3) 4 / 157 1.7 Numeración de la secuencia

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible have a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant mensajes. @startuml autonumber Bob -> Alice : Authentication Request Bob <- Alice : Authentication Response @enduml Guía de Referencia del Lenguaje PlantUML (1.2019.2) 4 / 157 1.7 Numeración de la secuencia

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible have a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant mensajes. @startuml autonumber Bob -> Alice : Authentication Request Bob <- Alice : Authentication Response @enduml Guía de Referencia del Lenguaje PlantUML (1.2019.6) 4 / 171 1.7 Numeración de la secuencia

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible have a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant mensajes. @startuml autonumber Bob -> Alice : Authentication Request Bob <- Alice : Authentication Response @enduml Guía de Referencia del Lenguaje PlantUML (1.2019.9) 4 / 171 1.7 Numeración de la secuencia

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible have a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant demonstrates\nmultiline \ntext @enduml 1.5 Text alignment 1.5.1 Text of response message below the arrow You can put the text of the response message below the arrow, with the skinparam responseMessageBelowArrow

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible have a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant demonstrates\nmultiline \ntext @enduml 1.5 Text alignment 1.5.1 Text of response message below the arrow You can put the text of the response message below the arrow, with the skinparam responseMessageBelowArrow

Authentication Request Bob --> Alice: Authentication Response Alice -> Bob: Another authentication Request Alice <-- Bob: another authentication Response @enduml 1.2 Declarando participantes Es posible have a really\nlong name" #99FF99 '/ Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml You can use the orderkeyword to custom the print order of participant demonstrates\nmultiline \ntext @enduml 1.5 Text alignment 1.5.1 Text of response message below the arrow You can put the text of the response message below the arrow, with the skinparam responseMessageBelowArrow