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use crate::parse::ParseErr; pub fn split(expr: &str) -> Result<Vec<&str>, ParseErr> { let mut begin = 0; let mut len = 0; let mut items = Vec::new(); let mut string = false; let mut escape = false; let mut line_comment = false; let mut comment = 0; while begin + len < expr.len() { let c = expr[begin + len..begin + len + 1].chars().next().unwrap(); if line_comment { if c == '\n' { line_comment = false; } begin += 1; } else if comment > 0 { if begin + len + 1 < expr.len() && &expr[begin + len..begin + len + 2] == "|#" { comment -= 1; begin += 1; } else if begin + len + 1 < expr.len() && &expr[begin + len..begin + len + 2] == "#|" { comment += 1; begin += 1; } begin += 1; } else if escape { len += 1; escape = false; } else if c == '\\' { escape = true; len += 1; } else if string { if c == '"' { string = false; } len += 1; } else if c == '"' && !string { string = true; len += 1; } else if c == ';' { if len > 0 { items.push(&expr[begin..begin + len]); } line_comment = true; begin += len + 1; len = 0; } else if begin + len + 1 < expr.len() && &expr[begin + len..begin + len + 2] == "#|" { if len > 0 { items.push(&expr[begin..begin + len]); } comment = 1; begin += len + 2; len = 0; } else if begin + len + 1 < expr.len() && &expr[begin + len..begin + len + 2] == "|#" { return Err(ParseErr::NoCommentStart); } else if "()[] \t\n".contains(c) { if len > 0 { items.push(&expr[begin..begin + len]); } begin += len; if "()[]".contains(c) { items.push(&expr[begin..begin + 1]); } len = 0; begin += 1; } else if c == '\'' { begin += 1; items.push("'"); } else if c == ',' { begin += 1; items.push(","); } else if c == '`' { begin += 1; items.push("`"); } else { len += 1; } } if string { if &expr[begin..begin + 1] == "\"" { Err(ParseErr::UnterminatedString(begin)) } else { Err(ParseErr::IncorrectSpacing(begin)) } } else if comment > 0 { Err(ParseErr::UnterminatedComment) } else { if expr.len() > begin && !line_comment { items.push(&expr[begin..begin + len]); } Ok(items) } } #[cfg(test)] mod test { macro_rules! test { ( $input:tt -> $( $output:tt )* ) => { assert_eq!(split($input).ok().unwrap(), vec![ $( $output ),* ] as Vec<&str>); } } use super::*; #[test] pub fn simple_splits() { test!("(f a b)" -> "(" "f" "a" "b" ")"); test!("()()()" -> "(" ")" "(" ")" "(" ")"); test!("((())" -> "(" "(" "(" ")" ")"); test!(") abc(" -> ")" "abc" "("); test!("abc de (a cfg (b d)) )" -> "abc" "de" "(" "a" "cfg" "(" "b" "d" ")" ")" ")"); test!("+-123 // <e> (%1 11>1) ?~" -> "+-123" "//" "<e>" "(" "%1" "11>1" ")" "?~"); test!("(f args ...)" -> "(" "f" "args" "..." ")"); } #[test] pub fn string_split() { test!("\"\"" -> "\"\""); test!("\"abcdef\"" -> "\"abcdef\""); test!("(abc \"def\" ghi)" -> "(" "abc" "\"def\"" "ghi" ")"); test!("(\"(\")" -> "(" "\"(\"" ")"); } #[test] pub fn char_escape_and_literals() { test!("(\\a" -> "(" "\\a"); test!("\\'" -> "\\'"); test!("\\\"" -> "\\\""); test!("(abc de (f #\\\\) #\\\") (gh #\\) (#\\i ())" -> "(" "abc" "de" "(" "f" "#\\\\" ")" "#\\\"" ")" "(" "gh" "#\\)" "(" "#\\i" "(" ")" ")"); test!("#true #f #\\t #\\em #\\tab" -> "#true" "#f" "#\\t" "#\\em" "#\\tab"); } #[test] pub fn comments() { test!(";abc\ndef;a" -> "def"); test!(";;; x y z \n a b c \n ;e" -> "a" "b" "c"); test!("this is an#|~~ inline |#comment" -> "this" "is" "an" "comment"); test!("[.(.#|.|#.].)" -> "[" "." "(" "." "." "]" "." ")"); test!("#|comment|#" -> ); test!("a#| #| c|# d|# f" -> "a" "f"); } #[test] pub fn quotes() { test!("'a" -> "'" "a"); test!("`(ab ,c d)" -> "`" "(" "ab" "," "c" "d" ")"); test!("ab `c" -> "ab" "`" "c"); } }