From eb39d82930d4e68ca570a8d27df9498a4c1f65fb Mon Sep 17 00:00:00 2001 From: iximeow Date: Wed, 20 Mar 2019 03:05:22 -0700 Subject: add traits for syntax highlighting and contextualized display these traits are not ideal but are what i can do in rust right now the initial attempt to add these traits involved a trait providing a `colorize` function that returned a struct (or tuple) that impl'd Display but bundled all useful data together. this would be nice because use would be like: ``` println!("the next instruction is: {}", instr.colorize(settings)); ``` but this runs into the same kind of lifetime issues as mentioned in the ContextRead commit. additionally complicating is contextualization, which involves a larger structure than just a copyable color setting - a similar builder-and-display style use would be nice but involves a third lifetime (the content, the colors, the contexts) and is not workable. references could be Rc pointers and this all might work. why not do that? moral opposition to cloning Rc pointers when doing any instruction rendering. might be worth revisiting later if i'm convinced this is too annoying - it's already close. meanwhile, it turns out implementing traits on tuples is currently not possible anyway - tuples are not #[fundamental]. in the future i need to investigate if i can use macros to tie into `derive`, so that a ShowContextual impl can #[derive(Colorize, Display)]. those implementations would really just call ShowContextual.colorize with fewer and fewer parameters non-None. the blanket impl ``` impl Colorize for T where T: ShowContextual ``` is entirely just a relic of one attempt, and can be ignored. this idea conflicted with coherence rules because someone else could impl Colorize for some type covered under this blanket impl. --- src/lib.rs | 43 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/lib.rs b/src/lib.rs index f1671b3..96c4144 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -2,7 +2,7 @@ extern crate num_traits; use std::str::FromStr; -use std::fmt::{Debug, Display}; +use std::fmt::{Debug, Display, Formatter}; use std::ops::{Add, Sub, AddAssign, SubAssign}; @@ -89,3 +89,44 @@ pub trait LengthedInstruction { fn len(&self) -> Self::Unit; fn min_size() -> Self::Unit; } + +pub struct ColorSettings { +} + +/* + * can this be a derivable trait or something? + */ +/* +impl Display for T { + fn fmt(&self, fmt: &mut Formatter) -> std::fmt::Result { + self.colorize(None, fmt) + } +} +*/ + +pub trait Colorize { + fn colorize(&self, colors: Option<&ColorSettings>, out: &mut T) -> std::fmt::Result; +} + +/* + * and make this auto-derive from a ShowContextual impl? + */ +/* +impl Colorize for T where T: ShowContextual { + fn colorize(&self, colors: Option<&ColorSettings>, fmt: &mut Formatter) -> std::fmt::Result { + self.contextualize(colors, None, fmt) + } +} +*/ + +pub trait ShowContextual { + fn contextualize(&self, colors: Option<&ColorSettings>, address: Addr, context: Option<&Ctx>, out: &mut T) -> std::fmt::Result; +} + +/* +impl > ShowContextual for U { + fn contextualize(&self, colors: Option<&ColorSettings>, context: Option<&C>, out: &mut T) -> std::fmt::Result { + self.colorize(colors, out) + } +} +*/ -- cgit v1.1