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/// Get line and column from offset and source text. |
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/// |
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/// Line number starts at 1. |
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/// Column number is in UTF-16 characters, and starts at 1. |
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/// |
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/// This matches Babel's output. |
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pub fn get_line_column(offset: u32, source_text: &str) -> (usize, usize) { |
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let offset = offset as usize; |
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let rope = Rope::from_str(source_text); |
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// Get line number and byte offset of start of line |
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let line_index = rope.byte_to_line(offset); |
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let line_offset = rope.line_to_byte(line_index); |
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// Get column number |
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let column_index = source_text[line_offset..offset].encode_utf16().count(); |
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// line and column are zero-indexed, but we want 1-indexed |
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(line_index + 1, column_index + 1) |
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} |
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fn offset_to_position(offset: usize, source_text: &str) -> Option<Position> { |
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let rope = Rope::from_str(source_text); |
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let line = rope.try_byte_to_line(offset).ok()?; |
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let first_char_of_line = rope.try_line_to_char(line).ok()?; |
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// Original offset is byte, but Rope uses char offset |
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let offset = rope.try_byte_to_char(offset).ok()?; |
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let column = offset - first_char_of_line; |
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Some(Position::new(line as u32, column as u32)) |
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} |
Rope::from_str(source_text) is too expensive.
