expectStatement

fn expectStatement(p: *Parse, is_block_level: bool) Error!Node.Index {
    if (p.eatToken(.keyword_comptime)) |comptime_token| {
        const opt_block_expr = try p.parseBlockExpr();
        if (opt_block_expr) |block_expr| {
            return p.addNode(.{
                .tag = .@"comptime",
                .main_token = comptime_token,
                .data = .{ .node = block_expr },
            });
        }

        if (is_block_level) {
            return p.expectVarAssignStatement(comptime_token);
        } else {
            const assign = try p.expectAssignExpr();
            try p.expectSemicolon(.expected_semi_after_stmt, true);
            if (p.nodeTag(assign) != .assign_destructure) {
                return p.addNode(.{
                    .tag = .@"comptime",
                    .main_token = comptime_token,
                    .data = .{ .node = assign },
                });
            } else {
                return assign;
            }
        }
    }

    switch (p.tokenTag(p.tok_i)) {
        .keyword_nosuspend => {
            return p.addNode(.{
                .tag = .@"nosuspend",
                .main_token = p.nextToken(),
                .data = .{ .node = try p.expectBlockExprStatement() },
            });
        },
        .keyword_suspend => {
            const token = p.nextToken();
            const block_expr = try p.expectBlockExprStatement();
            return p.addNode(.{
                .tag = .@"suspend",
                .main_token = token,
                .data = .{ .node = block_expr },
            });
        },
        .keyword_defer => if (is_block_level) return p.addNode(.{
            .tag = .@"defer",
            .main_token = p.nextToken(),
            .data = .{ .node = try p.expectBlockExprStatement() },
        }),
        .keyword_errdefer => if (is_block_level) return p.addNode(.{
            .tag = .@"errdefer",
            .main_token = p.nextToken(),
            .data = .{ .node = try p.expectBlockExprStatement() },
        }),
        .keyword_if => return p.expectIfStatement(),
        .keyword_enum, .keyword_struct, .keyword_union => {
            const identifier = p.tok_i + 1;
            if (try p.parseCStyleContainer()) {
                // Return something so that `expectStatement` is happy.
                return p.addNode(.{
                    .tag = .identifier,
                    .main_token = identifier,
                    .data = undefined,
                });
            }
        },
        else => {},
    }

    if (try p.parseLabeledStatement()) |labeled_statement| return labeled_statement;

    if (is_block_level) {
        return p.expectVarAssignStatement(null);
    } else {
        const assign = try p.expectAssignExpr();
        try p.expectSemicolon(.expected_semi_after_stmt, true);
        return assign;
    }
}