Zig 0.17.0-dev (Split by item)

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expectIfStatement

Parse.expectIfStatement

fn expectIfStatement(p: *Parse) !Node.Index

File

lib/std/zig/Parse.zig:1151

Code

fn expectIfStatement(p: *Parse) !Node.Index {
    const if_token = p.assertToken(.keyword_if);
    _ = try p.expectToken(.l_paren);
    const condition = try p.expectExpr();
    _ = try p.expectToken(.r_paren);
    _ = try p.parsePtrPayload();

    // TODO propose to change the syntax so that semicolons are always required
    // inside if statements, even if there is an `else`.
    var else_required = false;
    const then_expr = blk: {
        const block_expr = try p.parseBlockExpr();
        if (block_expr) |block| break :blk block;
        const assign_expr = try p.parseAssignExpr() orelse {
            return p.fail(.expected_block_or_assignment);
        };
        if (p.eatToken(.semicolon)) |_| {
            return p.addNode(.{
                .tag = .if_simple,
                .main_token = if_token,
                .data = .{ .node_and_node = .{
                    condition,
                    assign_expr,
                } },
            });
        }
        else_required = true;
        break :blk assign_expr;
    };
    _ = p.eatToken(.keyword_else) orelse {
        if (else_required) {
            try p.warn(.expected_semi_or_else);
        }
        return p.addNode(.{
            .tag = .if_simple,
            .main_token = if_token,
            .data = .{ .node_and_node = .{
                condition,
                then_expr,
            } },
        });
    };
    _ = try p.parsePayload();
    const else_expr = try p.expectStatement(false);
    return p.addNode(.{
        .tag = .@"if",
        .main_token = if_token,
        .data = .{ .node_and_extra = .{
            condition,
            try p.addExtra(Node.If{
                .then_expr = then_expr,
                .else_expr = else_expr,
            }),
        } },
    });
}