diff --git a/src/formatter.rs b/src/formatter.rs index 5270124..1b504dd 100644 --- a/src/formatter.rs +++ b/src/formatter.rs @@ -4,19 +4,52 @@ use log::debug; use crate::{extensions::FindFrom, types::LineType}; -#[derive(Debug, Clone, Copy, PartialEq, Eq)] +#[derive(Debug, Clone, Copy, Eq)] /// Represents a snippet from a page of a specific highlighting class. -pub enum PageSnippet<'a> { - CommandName(&'a str), - Variable(&'a str), - NormalCode(&'a str), - Description(&'a str), - Text(&'a str), - Title(&'a str), +pub enum PageSnippet { + CommandName(T), + Variable(T), + NormalCode(T), + Description(T), + Text(T), + Title(T), Linebreak, } -impl PageSnippet<'_> { +#[cfg_attr(not(test), allow(dead_code))] +impl PageSnippet { + pub fn map(self, f: F) -> PageSnippet + where + F: FnOnce(T) -> U, + { + match self { + PageSnippet::CommandName(s) => PageSnippet::CommandName(f(s)), + PageSnippet::Variable(s) => PageSnippet::Variable(f(s)), + PageSnippet::NormalCode(s) => PageSnippet::NormalCode(f(s)), + PageSnippet::Description(s) => PageSnippet::Description(f(s)), + PageSnippet::Text(s) => PageSnippet::Text(f(s)), + PageSnippet::Title(s) => PageSnippet::Title(f(s)), + PageSnippet::Linebreak => PageSnippet::Linebreak, + } + } +} + +impl, U> PartialEq> for PageSnippet { + fn eq(&self, other: &PageSnippet) -> bool { + match (self, other) { + (PageSnippet::CommandName(s), PageSnippet::CommandName(t)) + | (PageSnippet::Variable(s), PageSnippet::Variable(t)) + | (PageSnippet::NormalCode(s), PageSnippet::NormalCode(t)) + | (PageSnippet::Description(s), PageSnippet::Description(t)) + | (PageSnippet::Text(s), PageSnippet::Text(t)) + | (PageSnippet::Title(s), PageSnippet::Title(t)) => s == t, + (PageSnippet::Linebreak, PageSnippet::Linebreak) => true, + _ => false, + } + } +} + +impl PageSnippet<&str> { pub fn is_empty(&self) -> bool { use PageSnippet::*; @@ -38,7 +71,7 @@ pub fn highlight_lines( ) -> Result<(), E> where L: Iterator, - F: for<'snip> FnMut(PageSnippet<'snip>) -> Result<(), E>, + F: for<'snip> FnMut(PageSnippet<&'snip str>) -> Result<(), E>, { let mut command = String::new(); for line in lines { @@ -75,29 +108,82 @@ where Ok(()) } -/// Highlight code examples including user variables in {{ curly braces }}. -fn highlight_code<'a, E>( - command: &'a str, - text: &'a str, - process_snippet: &mut impl FnMut(PageSnippet<'a>) -> Result<(), E>, +/// Highlight code examples. +/// - parse placeholders (`{{ curly braces }}`) +/// - replace escaped placeholder markers (`\{\{` and `\}\}`) +fn highlight_code( + command: &str, + mut text: &str, + process_snippet: &mut impl FnMut(PageSnippet<&str>) -> Result<(), E>, ) -> Result<(), E> { - let variable_splits = text - .split("}}") - .map(|s| s.split_once("{{").unwrap_or((s, ""))); - for (code_segment, variable) in variable_splits { - highlight_code_segment(command, code_segment, process_snippet)?; - process_snippet(PageSnippet::Variable(variable))?; + // We replace escaped placeholder markers at the end so that our replacing does not interfere + // with finding the actual markers. + // NOTE: This is not optimal, as it allocates one String for each `replace` + let replace_escaped = |s: &str| s.replace(r"\{\{", "{{").replace(r"\}\}", "}}"); + + loop { + // Find placeholder markers and split into code and placeholder accordingly + + let Some(start_marker) = find_marker(text, "{{", r"\{\{") else { + break; + }; + let Some(mut end_marker) = find_marker(&text[start_marker + 2..], "}}", r"\}\}") else { + break; + }; + end_marker += start_marker + 2; + + // Greedily extend matched range + while end_marker + 2 < text.len() && text.as_bytes()[end_marker + 2] == b'}' { + end_marker += 1; + } + + let placeholder_content = &text[start_marker + 2..end_marker]; + + if start_marker > 0 { + highlight_code_segment( + command, + &replace_escaped(&text[..start_marker]), + process_snippet, + )?; + } + process_snippet(PageSnippet::Variable(&replace_escaped(placeholder_content)))?; + + text = &text[end_marker + 2..]; } + + if !text.is_empty() { + highlight_code_segment(command, &replace_escaped(text), process_snippet)?; + } + Ok(()) } +/// Find a "{{" (or "}}") substring that does not overlap with a preceding "\{\{" (or "\}\}"). +fn find_marker(s: &str, marker: &str, forbidden_prefix: &str) -> Option { + let mut search_start = 0; + loop { + let marker_index = s.find_from(marker, search_start)?; + + let overlaps_with_prefix = (forbidden_prefix.len() <= marker_index + 1) && { + let prefix_start = marker_index + 1 - forbidden_prefix.len(); + &s[prefix_start..=marker_index] == forbidden_prefix + }; + if !overlaps_with_prefix { + return Some(marker_index); + } + + // The next valid marker cannot include the first character of the current match + search_start = marker_index + 1; + } +} + /// Yields `NormalCode` and `CommandName` in alternating order according to the occurrences of /// `command_name` in `segment`. Variables are not detected here, see `highlight_code` /// instead. fn highlight_code_segment<'a, E>( command_name: &'a str, mut segment: &'a str, - process_snippet: &mut impl FnMut(PageSnippet<'a>) -> Result<(), E>, + process_snippet: &mut impl FnMut(PageSnippet<&'a str>) -> Result<(), E>, ) -> Result<(), E> { if !command_name.is_empty() { let mut search_start = 0; @@ -140,7 +226,6 @@ fn is_freestanding_substring(surrounding: &str, substring: (usize, usize)) -> bo #[cfg(test)] mod tests { use super::*; - use PageSnippet::*; #[test] fn test_is_freestanding_substring() { @@ -167,80 +252,186 @@ mod tests { )); } - fn run<'a>(cmd: &'a str, segment: &'a str) -> Vec> { + fn run<'a>(cmd: &'a str, segment: &'a str) -> Vec> { let mut yielded = Vec::new(); - let mut process_snippet = |snip: PageSnippet<'a>| { + let mut process_snippet = |snip: PageSnippet<&str>| { if !snip.is_empty() { - yielded.push(snip); + yielded.push(snip.map(str::to_string)); } Ok::<(), ()>(()) }; - highlight_code_segment(cmd, segment, &mut process_snippet) - .expect("highlight code segment failed"); + highlight_code(cmd, segment, &mut process_snippet).expect("highlight code segment failed"); yielded } - #[test] - fn test_highlight_code_segment() { - assert!(run("make", "").is_empty()); - assert_eq!( - &run("make", "make all CC=clang -q"), - &[CommandName("make"), NormalCode(" all CC=clang -q")] - ); - assert_eq!( - &run("make", " make money --always-make"), - &[ - NormalCode(" "), - CommandName("make"), - NormalCode(" money --always-make") - ] - ); - assert_eq!( - &run("git commit", "git commit -m 'git commit'"), - &[CommandName("git commit"), NormalCode(" -m 'git commit'"),] - ); + mod highlight_code_segment { + use super::*; + use PageSnippet::*; + + #[test] + fn test_highlight_code_segment() { + assert!(run("make", "").is_empty()); + assert_eq!( + &run("make", "make all CC=clang -q"), + &[CommandName("make"), NormalCode(" all CC=clang -q")] + ); + assert_eq!( + &run("make", " make money --always-make"), + &[ + NormalCode(" "), + CommandName("make"), + NormalCode(" money --always-make") + ] + ); + assert_eq!( + &run("git commit", "git commit -m 'git commit'"), + &[CommandName("git commit"), NormalCode(" -m 'git commit'"),] + ); + } + + #[test] + fn test_i18n() { + assert_eq!( + &run("mäke", "mäke höhlenrätselbücher"), + &[CommandName("mäke"), NormalCode(" höhlenrätselbücher")] + ); + assert_eq!( + &run( + "Müll", + "1000 Gründe warum Müll heute größer ist als Müll früher, ärgerlich" + ), + &[ + NormalCode("1000 Gründe warum "), + CommandName("Müll"), + NormalCode(" heute größer ist als "), + CommandName("Müll"), + NormalCode(" früher, ärgerlich") + ] + ); + assert_eq!( + &run( + "übergang", + "die Zustandsübergangsfunktion übergang Änderungen", + ), + &[ + NormalCode("die Zustandsübergangsfunktion "), + CommandName("übergang"), + NormalCode(" Änderungen") + ], + ); + } + + #[test] + fn test_empty_command() { + let segment = "some code"; + let snippets = [NormalCode(segment)]; + + assert_eq!(run("", segment), snippets); + assert_eq!(run(" ", segment), snippets); + assert_eq!(run(" \t ", segment), snippets); + } } - #[test] - fn test_i18n() { - assert_eq!( - &run("mäke", "mäke höhlenrätselbücher"), - &[CommandName("mäke"), NormalCode(" höhlenrätselbücher")] - ); - assert_eq!( - &run( - "Müll", - "1000 Gründe warum Müll heute größer ist als Müll früher, ärgerlich" - ), - &[ - NormalCode("1000 Gründe warum "), - CommandName("Müll"), - NormalCode(" heute größer ist als "), - CommandName("Müll"), - NormalCode(" früher, ärgerlich") - ] - ); - assert_eq!( - &run( - "übergang", - "die Zustandsübergangsfunktion übergang Änderungen", - ), - &[ - NormalCode("die Zustandsübergangsfunktion "), - CommandName("übergang"), - NormalCode(" Änderungen") - ], - ); - } + mod placeholders { + use super::*; + use PageSnippet::*; - #[test] - fn test_empty_command() { - let segment = "some code"; - let snippets = [NormalCode(segment)]; + #[test] + fn variable_vs_escaped() { + assert_eq!( + run("ping", "ping {{example.com}}"), + [ + CommandName("ping"), + NormalCode(" "), + Variable("example.com"), + ], + ); + assert_eq!( + run( + "docker inspect", + r"docker inspect --format '\{\{range.NetworkSettings.Networks\}\}\{\{.IPAddress\}\}\{\{end\}\}' {{container}}" + ), + [ + CommandName("docker inspect"), + NormalCode( + " --format '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' " + ), + Variable("container"), + ], + ); + assert_eq!( + run("mount", r"mount \\{{computer_name}}\{{share_name}} Z:"), + [ + CommandName("mount"), + NormalCode(r" \\"), + Variable("computer_name"), + NormalCode(r"\"), + Variable("share_name"), + NormalCode(" Z:"), + ], + ); - assert_eq!(run("", segment), snippets); - assert_eq!(run(" ", segment), snippets); - assert_eq!(run(" \t ", segment), snippets); + assert_eq!(run("", r"\{"), [NormalCode(r"\{")]); + assert_eq!(run("", r"\{{a"), [NormalCode(r"\{{a")]); + assert_eq!(run("", r"\{{a}}"), [NormalCode(r"\"), Variable("a")]); + + // Placeholder has begin marker, but no end marker + assert_eq!(run("", r"{{\}\}}"), [NormalCode("{{}}}")]); + } + + #[test] + fn outer_precedence() { + assert_eq!( + run("git stash", "git stash show --patch {{stash@{0}}}"), + [ + CommandName("git stash"), + NormalCode(" show --patch "), + Variable("stash@{0}"), + ], + ); + + // The following is not listed in the specification, but this is the highlighting I would expect. + assert_eq!( + run("rg", "rg {{}}}"), + [CommandName("rg"), NormalCode(" "), Variable("}")] + ); + + // And these are just to document the current behavior + assert_eq!(run("", "{{{}}}"), [Variable("{}")]); + assert_eq!(run("", "{{{{}}}"), [Variable("{{}")]); + assert_eq!(run("", "{{{}}}}"), [Variable("{}}")]); + } + + #[test] + fn escaped_inside_placeholder() { + assert_eq!( + run( + "playerctl", + r#"playerctl metadata {{[-f|--format]}} "{{Now playing: \{\{artist\}\} - \{\{album\}\} - \{\{title\}\}}}""# + ), + [ + CommandName("playerctl"), + NormalCode(" metadata "), + Variable("[-f|--format]"), + NormalCode(" \""), + Variable("Now playing: {{artist}} - {{album}} - {{title}}"), + NormalCode("\""), + ], + ); + } + + #[test] + fn placeholder_inside_escaped() { + assert_eq!( + run("test", r#"test \{\{{{var}} normal\}\}"#), + [ + CommandName("test"), + NormalCode(" {{"), + Variable("var"), + NormalCode(" normal}}"), + ], + ); + } } } diff --git a/src/output.rs b/src/output.rs index 5f1aeae..927d20e 100644 --- a/src/output.rs +++ b/src/output.rs @@ -56,7 +56,7 @@ pub fn print_page( } } else { // Closure that processes a page snippet and writes it to stdout - let mut process_snippet = |snip: PageSnippet<'_>| { + let mut process_snippet = |snip: PageSnippet<&str>| { if snip.is_empty() { Ok(()) } else { @@ -82,7 +82,7 @@ pub fn print_page( fn print_snippet( writer: &mut impl Write, - snip: PageSnippet<'_>, + snip: PageSnippet<&str>, style: &StyleConfig, ) -> io::Result<()> { use PageSnippet::*;