numberLiteral

fn numberLiteral(zg: *ZonGen, num_node: Ast.Node.Index, src_node: Ast.Node.Index, dest_node: Zoir.Node.Index, sign: enum

File

Code

fn numberLiteral(zg: *ZonGen, num_node: Ast.Node.Index, src_node: Ast.Node.Index, dest_node: Zoir.Node.Index, sign: enum { negative, positive }) !void {
    const tree = zg.tree;
    const num_token = tree.nodeMainToken(num_node);
    const num_bytes = tree.tokenSlice(num_token);

    switch (std.zig.parseNumberLiteral(num_bytes)) {
        .int => |unsigned_num| {
            if (unsigned_num == 0 and sign == .negative) {
                try zg.addErrorTokNotes(num_token, "integer literal '-0' is ambiguous", .{}, &.{
                    try zg.errNoteTok(num_token, "use '0' for an integer zero", .{}),
                    try zg.errNoteTok(num_token, "use '-0.0' for a floating-point signed zero", .{}),
                });
                return;
            }
            const num: i65 = switch (sign) {
                .positive => unsigned_num,
                .negative => -@as(i65, unsigned_num),
            };
            if (std.math.cast(i32, num)) |x| {
                zg.setNode(dest_node, .{
                    .tag = .int_literal_small,
                    .data = @bitCast(x),
                    .ast_node = src_node,
                });
                return;
            }
            const max_limbs = comptime std.math.big.int.calcTwosCompLimbCount(@bitSizeOf(@TypeOf(num)));
            var limbs: [max_limbs]std.math.big.Limb = undefined;
            var big_int: std.math.big.int.Mutable = .init(&limbs, num);
            try zg.setBigIntLiteralNode(dest_node, src_node, big_int.toConst());
        },
        .big_int => |base| {
            const gpa = zg.gpa;
            const num_without_prefix = switch (base) {
                .decimal => num_bytes,
                .hex, .binary, .octal => num_bytes[2..],
            };
            var big_int: std.math.big.int.Managed = try .init(gpa);
            defer big_int.deinit();
            big_int.setString(@backingInt(base), num_without_prefix) catch |err| switch (err) {
                error.InvalidCharacter => unreachable, // caught in `parseNumberLiteral`
                error.InvalidBase => unreachable, // we only pass 16, 8, 2, see above
                error.OutOfMemory => |e| return e,
            };
            switch (sign) {
                .positive => {},
                .negative => big_int.negate(),
            }
            try zg.setBigIntLiteralNode(dest_node, src_node, big_int.toConst());
        },
        .float => {
            const unsigned_num = std.fmt.parseFloat(f128, num_bytes) catch |err| switch (err) {
                error.InvalidCharacter => unreachable, // validated by tokenizer
            };
            const num: f128 = switch (sign) {
                .positive => unsigned_num,
                .negative => -unsigned_num,
            };

            {
                // If the value fits into an f32 without losing any precision, store it that way.
                @setFloatMode(.strict);
                const smaller_float: f32 = @floatCast(num);
                const bigger_again: f128 = smaller_float;
                if (bigger_again == num) {
                    zg.setNode(dest_node, .{
                        .tag = .float_literal_small,
                        .data = @bitCast(smaller_float),
                        .ast_node = src_node,
                    });
                    return;
                }
            }

            const elems: [4]u32 = @bitCast(num);
            const extra_index: u32 = @intCast(zg.extra.items.len);
            try zg.extra.appendSlice(zg.gpa, &elems);
            zg.setNode(dest_node, .{
                .tag = .float_literal,
                .data = extra_index,
                .ast_node = src_node,
            });
        },
        .failure => |err| try zg.lowerNumberError(err, num_token, num_bytes),
    }
}