feedLine

pub fn feedLine(p: *Parser, line: []const u8) Allocator.Error!void

File

Code

pub fn feedLine(p: *Parser, line: []const u8) Allocator.Error!void {
    var rest_line = line;
    const first_unmatched = for (p.pending_blocks.items, 0..) |b, i| {
        if (b.match(rest_line)) |rest| {
            rest_line = rest;
        } else {
            break i;
        }
    } else p.pending_blocks.items.len;

    const in_code_block = p.pending_blocks.items.len > 0 and
        p.pending_blocks.getLast().?.tag == .code_block;
    const code_block_end = in_code_block and
        first_unmatched + 1 == p.pending_blocks.items.len;
    // New blocks cannot be started if we are actively inside a code block or
    // are just closing one (to avoid interpreting the closing ``` as a new code
    // block start).
    var maybe_block_start = if (!in_code_block or first_unmatched + 2 <= p.pending_blocks.items.len)
        try p.startBlock(rest_line)
    else
        null;

    // This is a lazy continuation line if there are no new blocks to open and
    // the last open block is a paragraph.
    if (maybe_block_start == null and
        !isBlank(rest_line) and
        p.pending_blocks.items.len > 0 and
        p.pending_blocks.getLast().?.tag == .paragraph)
    {
        try p.addScratchStringLine(mem.trimStart(u8, rest_line, " \t"));
        return;
    }

    // If a new block needs to be started, any paragraph needs to be closed,
    // even though this isn't detected as part of the closing condition for
    // paragraphs.
    if (maybe_block_start != null and
        p.pending_blocks.items.len > 0 and
        p.pending_blocks.getLast().?.tag == .paragraph)
    {
        try p.closeLastBlock();
    }

    while (p.pending_blocks.items.len > first_unmatched) {
        try p.closeLastBlock();
    }

    while (maybe_block_start) |block_start| : (maybe_block_start = try p.startBlock(rest_line)) {
        try p.appendBlockStart(block_start);
        // There may be more blocks to start within the same line.
        rest_line = block_start.rest;
        // Headings may only contain inline content.
        if (block_start.tag == .heading) break;
        // An opening code fence does not contain any additional block or inline
        // content to process.
        if (block_start.tag == .code_block) return;
    }

    // Do not append the end of a code block (```) as textual content.
    if (code_block_end) return;

    const can_accept = if (p.pending_blocks.getLast()) |last_pending_block|
        last_pending_block.canAccept()
    else
        .blocks;
    const rest_line_trimmed = mem.trimStart(u8, rest_line, " \t");
    switch (can_accept) {
        .blocks => {
            // If we're inside a list item and the rest of the line is blank, it
            // means that any subsequent child of the list item (or subsequent
            // item in the list) will cause the containing list to be considered
            // loose. However, we can't immediately declare that the list is
            // loose, since we might just be looking at a blank line after the
            // end of the last item in the list. The final determination will be
            // made when appending the next child of the list or list item.
            const maybe_containing_list_index = if (p.pending_blocks.items.len > 0 and p.pending_blocks.getLast().?.tag == .list_item)
                p.pending_blocks.items.len - 2
            else
                null;

            if (rest_line_trimmed.len > 0) {
                try p.appendBlockStart(.{
                    .tag = .paragraph,
                    .data = .{ .none = {} },
                    .rest = undefined,
                });
                try p.addScratchStringLine(rest_line_trimmed);
            }

            if (maybe_containing_list_index) |containing_list_index| {
                p.pending_blocks.items[containing_list_index].data.list.last_line_blank = rest_line_trimmed.len == 0;
            }
        },
        .inlines => try p.addScratchStringLine(rest_line_trimmed),
        .raw_inlines => try p.addScratchStringLine(rest_line),
        .nothing => {},
    }
}