tiny.chant.ast.types.numeric

1const std = @import("std");2const types = @import("types.zig");34const Kind = types.Kind;5const Type = types.Type;67pub fn isInteger(c_type: *const Type) bool {8    return switch (c_type.kind) {9        .char_type, .short_type, .int_type, .long_type, .bitint_type, .enum_type => true,10        else => false,11    };12}1314pub fn isFloat(c_type: *const Type) bool {15    return switch (c_type.kind) {16        .float_type, .double_type, .decimal32_type, .decimal64_type, .decimal128_type => true,17        else => false,18    };19}2021pub fn isArithmetic(c_type: *const Type) bool {22    return isInteger(c_type) or isFloat(c_type);23}2425pub fn integerRank(c_type: *const Type) u32 {26    return switch (c_type.kind) {27        .char_type => standardRank(8),28        .short_type => standardRank(16),29        .int_type => standardRank(32),30        .long_type => standardRank(64),31        .bitint_type => bitintRank(c_type.bit_width),32        .enum_type => integerRank(c_type.child orelse &types.int_type),33        else => 0,34    };35}3637fn standardRank(width: u16) u32 {38    return @as(u32, width) * 2 + 1;39}4041fn bitintRank(width: u16) u32 {42    return @as(u32, width) * 2;43}4445pub fn commonArithmetic(lhs: *const Type, rhs: *const Type) *const Type {46    const lhs_promoted = promoteInteger(arithmeticIntegerType(lhs));47    const rhs_promoted = promoteInteger(arithmeticIntegerType(rhs));48    if (lhs_promoted != lhs or rhs_promoted != rhs) return commonArithmetic(lhs_promoted, rhs_promoted);49    if (lhs.kind == .decimal128_type or rhs.kind == .decimal128_type) return &types.decimal128_type;50    if (lhs.kind == .decimal64_type or rhs.kind == .decimal64_type) return &types.decimal64_type;51    if (lhs.kind == .decimal32_type or rhs.kind == .decimal32_type) return &types.decimal32_type;52    if (lhs.kind == .double_type or rhs.kind == .double_type) return &types.double_type;53    if (lhs.kind == .float_type or rhs.kind == .float_type) return &types.float_type;54    const lhs_rank = integerRank(lhs);55    const rhs_rank = integerRank(rhs);56    const wider = if (lhs_rank >= rhs_rank) lhs else rhs;57    if (wider.kind != .bitint_type and integerRank(wider) < integerRank(&types.int_type)) {58        return &types.int_type;59    }60    if (integerRank(lhs) == integerRank(rhs) and (lhs.is_unsigned or rhs.is_unsigned)) {61        return if (lhs.is_unsigned) lhs else rhs;62    }63    return wider;64}6566fn promoteInteger(c_type: *const Type) *const Type {67    if (c_type.kind == .bitint_type) return c_type;68    if (isInteger(c_type) and integerRank(c_type) < integerRank(&types.int_type)) return &types.int_type;69    return c_type;70}7172fn arithmeticIntegerType(c_type: *const Type) *const Type {73    if (c_type.kind == .enum_type) return c_type.child orelse &types.int_type;74    return c_type;75}7677test "usual arithmetic conversions prefer floats then rank" {78    try std.testing.expectEqual(Kind.double_type, commonArithmetic(&types.int_type, &types.double_type).kind);79    try std.testing.expectEqual(Kind.float_type, commonArithmetic(&types.float_type, &types.long_type).kind);80    try std.testing.expectEqual(Kind.decimal64_type, commonArithmetic(&types.decimal32_type, &types.decimal64_type).kind);81    try std.testing.expectEqual(Kind.decimal32_type, commonArithmetic(&types.double_type, &types.decimal32_type).kind);82    try std.testing.expectEqual(Kind.long_type, commonArithmetic(&types.int_type, &types.long_type).kind);83    try std.testing.expectEqual(Kind.int_type, commonArithmetic(&types.char_type, &types.short_type).kind);84    try std.testing.expect(commonArithmetic(&types.uint_type, &types.int_type).is_unsigned);8586    const bitint17 = Type{ .kind = .bitint_type, .bit_width = 17 };87    const bitint33 = Type{ .kind = .bitint_type, .bit_width = 33 };88    const fixed_enum = Type{ .kind = .enum_type, .child = &types.uchar_type };89    const wide_enum = Type{ .kind = .enum_type, .child = &types.uint_type };90    try std.testing.expectEqual(Kind.bitint_type, commonArithmetic(&bitint17, &bitint33).kind);91    try std.testing.expectEqual(@as(u16, 33), commonArithmetic(&bitint17, &bitint33).bit_width);92    try std.testing.expectEqual(Kind.int_type, commonArithmetic(&bitint17, &types.int_type).kind);93    try std.testing.expectEqual(Kind.int_type, commonArithmetic(&bitint17, &types.short_type).kind);94    try std.testing.expectEqual(Kind.bitint_type, commonArithmetic(&bitint33, &types.int_type).kind);95    try std.testing.expectEqual(Kind.int_type, commonArithmetic(&fixed_enum, &types.int_type).kind);96    try std.testing.expectEqual(Kind.int_type, commonArithmetic(&wide_enum, &types.int_type).kind);97    try std.testing.expect(commonArithmetic(&wide_enum, &types.int_type).is_unsigned);98}

1pub const numeric = numeric_mod;