u8.fz
# This file is part of the Fuzion language implementation. # # The Fuzion language implementation is free software: you can redistribute it # and/or modify it under the terms of the GNU General Public License as published # by the Free Software Foundation, version 3 of the License. # # The Fuzion language implementation is distributed in the hope that it will be # useful, but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public # License for more details. # # You should have received a copy of the GNU General Public License along with The # Fuzion language implementation. If not, see <https://www.gnu.org/licenses/>. # ----------------------------------------------------------------------- # # Tokiwa Software GmbH, Germany # # Source code of Fuzion standard library feature u8 # # Author: Fridtjof Siebert (siebert@tokiwa.software) # # ----------------------------------------------------------------------- # u8 -- 8-bit unsigned integer values # public u8(public val u8) : num.wrap_around, has_interval is public thiz => u8.this.val # overflow checking # would negation -thiz cause an overflow? redef wrapped_on_neg => !is_zero # would addition thiz + other cause an overflow or underflow? public fixed overflow_on_add (other u8) => u8.max -° thiz < other public fixed underflow_on_add(other u8) => false # would subtraction thiz - other cause an overflow or underflow? public fixed overflow_on_sub (other u8) => false public fixed underflow_on_sub(other u8) => thiz < other # would multiplication thiz * other cause an overflow or underflow? public fixed overflow_on_mul (other u8) => as_i32 *° other.as_i32 > u8.max.as_i32 public fixed underflow_on_mul(other u8) => false # neg, add, sub, mul with wrap-around semantics public fixed prefix -° u8 => intrinsic public fixed infix +° (other u8) u8 => intrinsic public fixed infix -° (other u8) u8 => intrinsic public fixed infix *° (other u8) u8 => intrinsic # division and remainder with check for div-by-zero public fixed infix / (other u8) pre safety: other != 0 => div other public fixed infix % (other u8) pre safety: other != 0 => mod other # private division and remainder with crash in case of div-by-zero private div (other u8) u8 => intrinsic private mod (other u8) u8 => intrinsic # bitwise and, or and xor operations public fixed infix & (other u8) u8 => intrinsic public fixed infix | (other u8) u8 => intrinsic public fixed infix ^ (other u8) u8 => intrinsic # shift operations (unsigned) public fixed infix >> (other u8) u8 => intrinsic public fixed infix << (other u8) u8 => intrinsic public as_i8 i8 pre debug: thiz ≤ i8.max.as_u8 => cast_to_i8 public as_i16 => as_i32.as_i16 public as_i32 i32 => intrinsic public as_i64 => as_i32.as_i64 # as_i128 => as_i32.as_i128 public as_u8 => val public as_u16 => as_i32.as_u16 public as_u32 => as_i32.as_u32 public as_u64 => as_i32.as_u64 public as_u128 => as_i32.as_u128 public as_int => int as_i64 public cast_to_i8 i8 => intrinsic # create hash code from this number public type.hash_code(a u8.this) u64 => hash a.as_u64 # find the highest 1 bit in this integer and return integer with # this single bit set or 0 if this is 0. # public highest_one_bit u8 => // NYI: should be possible to reuse v, s names (v0, s0) := (val, u8 0) (v1, s1) := if (v0 < u8 0x10) (v0, s0) else (v0 >> 4, s0 + 4) (v2, s2) := if (v1 < u8 4) (v1, s1) else (v1 >> 2, s1 + 2) (v3, s3) := if (v2 < u8 2) (v2, s2) else (v2 >> 1, s2 + 1) v3 << s3 # count the number of trailing zeros in this integer. # public trailing_zeros i32 => // NYI: should be possible to reuse v, s names (v0, s0) := (val, 0) (v1, s1) := if (v0 & 0xf) != u8 0 then (v0, s0) else (v0 >> 4, s0 + 4) (v2, s2) := if (v1 & 3) != u8 0 then (v1, s1) else (v1 >> 2, s1 + 2) (v3, s3) := if (v2 & 1) != u8 0 then (v2, s2) else (v2 >> 1, s2 + 1) s4 := if (v3 & 1) != u8 0 then s3 else 8 s4 # count the number of 1 bits in the binary representation of this # integer. # public ones_count i32 => v := val.as_i32 m := v & 0xaa; v := v - m + (m >> 1) m := v & 0xcc; v := v - m + (m >> 2) m := v & 0xf0; v := v - m + (m >> 4) v # the least significant byte of this integer public low8bits u8 => val # is this u8 an ASCII white-space character? # public is_ascii_white_space => (val = (u8 9) || // HT val = (u8 10) || // LF val = (u8 11) || // VT val = (u8 12) || // FF val = (u8 13) || // CR val = (u8 32) // SPACE ) # ----------------------------------------------------------------------- # # type features: # identity element for 'infix +' # fixed type.zero u8 => 0 # identity element for 'infix *' # fixed type.one u8 => 1 # equality # fixed type.equality(a, b u8) bool => intrinsic_constructor # total order # fixed type.lteq(a, b u8) bool => intrinsic_constructor # returns the number in whose bit representation all bits are ones fixed type.all_bits_set => u8 0xff # minimum # public fixed type.min => u8 0 # maximum # public fixed type.max => u8 0xff