color_print_proc_macro/
ansi.rs

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1//! This module is only used when the feature `terminfo` is not activated.
2
3use proc_macro::TokenStream;
4use proc_macro2::TokenStream as TokenStream2;
5use quote::{quote, ToTokens};
6
7use crate::color_context::Context;
8use crate::error::{SpanError, Error};
9use crate::format_args::{
10    parse_args, get_format_string, get_args_and_format_string, parse_format_string, Node
11};
12
13/// Common code shared between the public macros, ANSI implementation.
14pub fn get_format_args(input: TokenStream) -> Result<TokenStream2, SpanError> {
15    let (format_string_token, args) = get_args_and_format_string(input)?;
16    let format_string = format_string_token.value();
17
18    // Split the format string into a list of nodes; each node is either a string literal (text), a
19    // placeholder for a `format!`-like macro, or a color code:
20    let format_nodes = parse_format_string(&format_string, &format_string_token)?;
21
22    let final_format_string = get_format_string_from_nodes(format_nodes)?;
23
24    // Group all the final arguments into a single iterator:
25    let args = args.iter()
26        .map(|arg| arg.to_token_stream())
27        .skip(1); // Skip the original format string
28    let final_args = std::iter::once(final_format_string).chain(args);
29
30    Ok(quote! { #(#final_args),* })
31}
32
33/// Transforms a string literal by parsing its color tags.
34pub fn get_cstr(input: TokenStream) -> Result<TokenStream2, SpanError> {
35    let args = parse_args(input)?;
36    let format_string_token = get_format_string(args.first())?;
37    let format_string = format_string_token.value();
38
39    if args.len() > 1 {
40        return Err(SpanError::new(Error::TooManyArgs, None));
41    }
42
43    // Split the format string into a list of nodes; each node is either a string literal (text),
44    // or a color code; `format!`-like placeholders will be parsed indenpendently, but as they are
45    // put back unchanged into the format string, it's not a problem:
46    let format_nodes = parse_format_string(&format_string, &format_string_token)?;
47    get_format_string_from_nodes(format_nodes)
48}
49
50/// Generates a new format string with the color tags replaced by the right ANSI codes.
51fn get_format_string_from_nodes(nodes: Vec<Node>) -> Result<TokenStream2, SpanError> {
52    // The final, modified format string which will be given to the `format!`-like macro:
53    let mut format_string = String::new();
54    // Stores which colors and attributes are set while processing the format string:
55    let mut color_context = Context::new();
56
57    // Generate the final format string:
58    for node in nodes {
59        match node {
60            Node::Text(s) | Node::Placeholder(s) => {
61                format_string.push_str(s);
62            }
63            Node::ColorTagGroup(tag_group) => {
64                let ansi_string = color_context.ansi_apply_tags(tag_group)?;
65                format_string.push_str(&ansi_string);
66            }
67        }
68    }
69
70    Ok(quote! { #format_string })
71}
color_print_proc_macro/ansi.rs

color_print_proc_macro/
ansi.rs
