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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /gfx/wr/wrench/src/parse_function.rs | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | gfx/wr/wrench/src/parse_function.rs | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/gfx/wr/wrench/src/parse_function.rs b/gfx/wr/wrench/src/parse_function.rs new file mode 100644 index 0000000000..92040b7680 --- /dev/null +++ b/gfx/wr/wrench/src/parse_function.rs @@ -0,0 +1,134 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +use std::str::CharIndices; + +// support arguments like '4', 'ab', '4.0', '>=10.14', '*123' +fn acceptable_arg_character(c: char) -> bool { + c.is_alphanumeric() || c == '.' || c == '-' || c == '<' || c == '>' || c == '=' || c == '*' +} + +// A crappy parser for parsing strings like "translate(1, 3) blahblah" +// Returns a tuple with three components: +// - First component is the function name (e.g. "translate") +// - Second component is the list of arguments (e.g. vec!["1", "3"]) +// - Third component is the rest of the string "blahblah" +pub fn parse_function(s: &str) -> (&str, Vec<&str>, &str) { + // XXX: This is not particularly easy to read. Sorry. + struct Parser<'a> { + itr: CharIndices<'a>, + start: usize, + o: Option<(usize, char)>, + } + impl<'a> Parser<'a> { + fn skip_whitespace(&mut self) { + while let Some(k) = self.o { + if !k.1.is_whitespace() { + break; + } + self.start = k.0 + k.1.len_utf8(); + self.o = self.itr.next(); + } + } + } + let mut c = s.char_indices(); + let o = c.next(); + let mut p = Parser { + itr: c, + start: 0, + o, + }; + + p.skip_whitespace(); + + let mut end = p.start; + while let Some(k) = p.o { + if !k.1.is_alphabetic() && k.1 != '_' && k.1 != '-' { + break; + } + end = k.0 + k.1.len_utf8(); + p.o = p.itr.next(); + } + + let name = &s[p.start .. end]; + let mut args = Vec::new(); + + p.skip_whitespace(); + + if let Some(k) = p.o { + if k.1 != '(' { + return (name, args, &s[p.start ..]); + } + p.start = k.0 + k.1.len_utf8(); + p.o = p.itr.next(); + } + + loop { + p.skip_whitespace(); + + let mut end = p.start; + let mut brackets: Vec<char> = Vec::new(); + while let Some(k) = p.o { + let prev_bracket_count = brackets.len(); + match k.1 { + '[' | '(' => brackets.push(k.1), + ']' | ')' => { + let open_bracket = match k.1 { + ']' => '[', + ')' => '(', + _ => panic!(), + }; + match brackets.pop() { + // Allow final closing ) for command invocation after args + None if k.1 == ')' => break, + Some(bracket) if bracket == open_bracket => {} + _ => panic!("Unexpected closing bracket {}", k.1), + } + } + _ => {} + } + + let not_in_bracket = brackets.is_empty() && prev_bracket_count == 0; + if !acceptable_arg_character(k.1) && not_in_bracket { + break; + } + end = k.0 + k.1.len_utf8(); + p.o = p.itr.next(); + } + + args.push(&s[p.start .. end]); + + p.skip_whitespace(); + + if let Some(k) = p.o { + p.start = k.0 + k.1.len_utf8(); + p.o = p.itr.next(); + // unless we find a comma we're done + if k.1 != ',' { + if k.1 != ')' { + panic!("Unexpected closing character: {}", k.1); + } + break; + } + } else { + break; + } + } + (name, args, &s[p.start ..]) +} + +#[test] +fn test() { + assert_eq!(parse_function("rotate(40)").0, "rotate"); + assert_eq!(parse_function(" rotate(40)").0, "rotate"); + assert_eq!(parse_function(" rotate (40)").0, "rotate"); + assert_eq!(parse_function(" rotate ( 40 )").1[0], "40"); + assert_eq!(parse_function("rotate(-40.0)").1[0], "-40.0"); + assert_eq!(parse_function("drop-shadow(0, [1, 2, 3, 4], 5)").1[0], "0"); + assert_eq!(parse_function("drop-shadow(0, [1, 2, 3, 4], 5)").1[1], "[1, 2, 3, 4]"); + assert_eq!(parse_function("drop-shadow(0, [1, 2, 3, 4], 5)").1[2], "5"); + assert_eq!(parse_function("drop-shadow(0, [1, 2, [3, 4]], 5)").1[1], "[1, 2, [3, 4]]"); + assert_eq!(parse_function("func(nest([1, 2]), [3, 4])").1[0], "nest([1, 2])"); + assert_eq!(parse_function("func(nest([1, 2]), [nest(3), nest(4)])").1[1], "[nest(3), nest(4)]"); +} |