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| 1 | namespace Semantic.Types is | |
| 2 | use IO.Std; | |
| 3 | ||
| 4 | use Logging; | |
| 5 | ||
| 6 | class NAMED: Type is | |
| 7 | _compare_count: int static; | |
| 8 | _same_count: int static; | |
| 9 | _named_count: int static; | |
| 10 | _hit_count: int static; | |
| 11 | _miss_count: int static; | |
| 12 | ||
| 13 | _cache: Collections.MutableMap[(int,int), Types.MATCH] static; | |
| 14 | ||
| 15 | name: string => symbol.name; | |
| 16 | scope: Scope => symbol; | |
| 17 | ||
| 18 | _symbol: Symbols.Symbol; | |
| 19 | ||
| 20 | // Set when this reference type was written with a `?` | |
| 21 | // nullability annotation. Directional: a `T?` slot accepts a | |
| 22 | // `T` value (widening); a `T` slot does not accept a `T?` | |
| 23 | // value (would lose the discriminator). | |
| 24 | _is_optional: bool; | |
| 25 | ||
| 26 | symbol: Symbols.Symbol => _symbol; | |
| 27 | ||
| 28 | is_optional: bool => _is_optional; | |
| 29 | ||
| 30 | optional_inner_type: Type? => | |
| 31 | if _is_optional then as_non_optional() else null fi; | |
| 32 | ||
| 33 | short_description: string => | |
| 34 | if _is_optional then | |
| 35 | "{symbol.name}?"; | |
| 36 | else | |
| 37 | symbol.name; | |
| 38 | fi; | |
| 39 | ||
| 40 | is_type_variable: bool => | |
| 41 | symbol.is_type_variable; | |
| 42 | ||
| 43 | is_named: bool => true; | |
| 44 | ||
| 45 | is_value_type: bool => symbol.is_value_type; | |
| 46 | is_trait: bool => symbol.is_trait; | |
| 47 | is_inheritable: bool => symbol.is_inheritable; | |
| 48 | is_class: bool => symbol.is_class; | |
| 49 | is_object: bool => symbol.is_object; | |
| 50 | is_root_value_type: bool => symbol.is_root_value_type; | |
| 51 | is_void: bool => symbol.is_void; | |
| 52 | ||
| 53 | init(symbol: Symbols.Symbol) is | |
| 54 | super.init(); | |
| 55 | ||
| 56 | _symbol = symbol; | |
| 57 | si | |
| 58 | ||
| 59 | matches(other: Type) -> bool => | |
| 60 | if other.is_sentinel then | |
| 61 | true; | |
| 62 | elif isa ONE_OF(other) /\ !isa ONE_OF(self) then | |
| 63 | // ONE_OF carries the underlying union's symbol but | |
| 64 | // narrows to a proper variant subset — never matches | |
| 65 | // the plain union it was built over. ONE_OF's own `matches` | |
| 66 | // override handles the ONE_OF-against-ONE_OF case. | |
| 67 | false; | |
| 68 | elif isa INTERSECTION(other) /\ !isa INTERSECTION(self) then | |
| 69 | // INTERSECTION inherits NAMED with members[0].symbol | |
| 70 | // as its "primary" symbol, but the intersection is | |
| 71 | // not the same type as a plain NAMED holding that | |
| 72 | // symbol — `Symbol` does not match `Symbol & Trait`. | |
| 73 | // INTERSECTION's own `matches` override handles the | |
| 74 | // INTERSECTION-against-INTERSECTION case. | |
| 75 | false; | |
| 76 | elif isa NAMED(other) then | |
| 77 | let other_symbol = other; | |
| 78 | symbol == other_symbol.symbol; | |
| 79 | else | |
| 80 | false; | |
| 81 | fi; | |
| 82 | ||
| 83 | is_equivalent_to(other: Type) -> bool => | |
| 84 | self.matches(other) /\ (other.is_sentinel \/ is_optional == other.is_optional); | |
| 85 | ||
| 86 | specialize(type_map: Collections.Map[string,Type]) -> Type => | |
| 87 | if type_map.contains_key(name) then | |
| 88 | // A flagged `T?` keeps its nullability when `T` is | |
| 89 | // substituted — `T?` with `T := Foo` is `Foo?`. | |
| 90 | if _is_optional then | |
| 91 | type_map[name].as_optional(); | |
| 92 | else | |
| 93 | type_map[name]; | |
| 94 | fi; | |
| 95 | else | |
| 96 | self; | |
| 97 | fi; | |
| 98 | ||
| 99 | _cache_result(other: Type, result: Types.MATCH) -> Types.MATCH is | |
| 100 | _cache[(self.symbol.get_hash_code(), other.symbol.get_hash_code())] = result; | |
| 101 | ||
| 102 | return result; | |
| 103 | si | |
| 104 | ||
| 105 | dump_stats() static is | |
| 106 | debug_always("cache size: {_cache.count} named ratio: {cast double(_hit_count) / cast double(_named_count)}"); | |
| 107 | ||
| 108 | debug_always("total: {_compare_count} named: {_named_count} same: {_same_count} misses: {_miss_count} hits: {_hit_count}"); | |
| 109 | si | |
| 110 | ||
| 111 | clear_cache() static is | |
| 112 | if _cache == null then | |
| 113 | _cache = Collections.MAP[(int,int), Types.MATCH](); | |
| 114 | fi | |
| 115 | ||
| 116 | _cache.clear(); | |
| 117 | si | |
| 118 | ||
| 119 | compare(other: Type) -> Types.MATCH is | |
| 120 | _compare_count = _compare_count + 1; | |
| 121 | if other.is_sentinel then | |
| 122 | return Types.MATCH.ASSIGNABLE; | |
| 123 | fi | |
| 124 | ||
| 125 | // `null` is assignable to any reference type, and to a | |
| 126 | // type written `T?` — including a `class`-constrained | |
| 127 | // type variable, which otherwise reports is_value_type. | |
| 128 | if other.is_null /\ (!is_value_type \/ _is_optional) then | |
| 129 | return Types.MATCH.ASSIGNABLE; | |
| 130 | fi | |
| 131 | ||
| 132 | // Ghul.MAYBE[T] → reference-T? widening. The carrier's | |
| 133 | // `value` field already holds the reference (null when | |
| 134 | // absent, the user's reference when present), so a single | |
| 135 | // property load at the slot boundary is the whole coercion. | |
| 136 | if _is_optional /\ !is_value_type /\ other.is_maybe then | |
| 137 | let other_inner = other.optional_inner_type; | |
| 138 | ||
| 139 | if other_inner? /\ self.as_non_optional().is_assignable_from(other_inner) then | |
| 140 | return Types.MATCH.ASSIGNABLE; | |
| 141 | fi | |
| 142 | fi | |
| 143 | ||
| 144 | if symbol == null then | |
| 145 | return Types.MATCH.DIFFERENT; | |
| 146 | elif other.is_named then | |
| 147 | _named_count = _named_count + 1; | |
| 148 | ||
| 149 | // Strict non-nullable-by-default: a `T` slot never | |
| 150 | // accepts a `T?` value. The caller must narrow first | |
| 151 | // (`x!`, `if let`, `if x?`). This applies uniformly | |
| 152 | // — symbol equality and subtype relationships below | |
| 153 | // don't loosen it. Without this check, the ancestor | |
| 154 | // walk below silently drops the optional flag because | |
| 155 | // ancestor types are bare (see `Symbol.ancestors`). | |
| 156 | // | |
| 157 | // Wild placeholders (unbound type variables) skip | |
| 158 | // this — a wild `T` matches anything during overload | |
| 159 | // resolution's first pass, and binding picks up the | |
| 160 | // optional flag from the actual. | |
| 161 | if !is_wild /\ !_is_optional /\ other.is_optional then | |
| 162 | return Types.MATCH.DIFFERENT; | |
| 163 | fi | |
| 164 | ||
| 165 | if symbol == other.symbol then | |
| 166 | if _is_optional == other.is_optional then | |
| 167 | _same_count = _same_count + 1; | |
| 168 | return Types.MATCH.SAME; | |
| 169 | else | |
| 170 | // `T?` slot accepts `T` value via the implicit | |
| 171 | // widening — null becomes the absent marker, a | |
| 172 | // non-null reference flows through unchanged. | |
| 173 | // (The `T` slot accepting `T?` case is already | |
| 174 | // rejected by the strict check above.) | |
| 175 | return Types.MATCH.ASSIGNABLE; | |
| 176 | fi | |
| 177 | fi | |
| 178 | ||
| 179 | let result: Types.MATCH mut = _; | |
| 180 | ||
| 181 | if _cache == null then | |
| 182 | _cache = Collections.MAP[(int,int),Types.MATCH](); | |
| 183 | fi | |
| 184 | ||
| 185 | if _cache.try_get_value((self.symbol.get_hash_code(), other.symbol.get_hash_code()), result ref) then | |
| 186 | _hit_count = _hit_count + 1; | |
| 187 | return result; | |
| 188 | fi | |
| 189 | ||
| 190 | _miss_count = _miss_count + 1; | |
| 191 | ||
| 192 | for a in other.symbol.ancestors do | |
| 193 | let match = self.compare(a); | |
| 194 | ||
| 195 | if cast int(match) <= cast int(Types.MATCH.ASSIGNABLE) then | |
| 196 | return _cache_result(other, Types.MATCH.ASSIGNABLE); | |
| 197 | elif match == Types.MATCH.CONVERTABLE then | |
| 198 | return _cache_result(other, Types.MATCH.CONVERTABLE); | |
| 199 | fi | |
| 200 | od | |
| 201 | ||
| 202 | if is_wild \/ other.is_wild then | |
| 203 | return _cache_result(other, Types.MATCH.WILD); | |
| 204 | fi | |
| 205 | ||
| 206 | return _cache_result(other, Types.MATCH.DIFFERENT); | |
| 207 | fi | |
| 208 | ||
| 209 | // FIXME: should we be caching this result? | |
| 210 | return Types.MATCH.DIFFERENT; | |
| 211 | si | |
| 212 | ||
| 213 | find_member(name: string) -> Symbols.Symbol? => symbol.find_member(name); | |
| 214 | ||
| 215 | get_destructure_member_name(index: int) -> string? => symbol.get_destructure_member_name(index); | |
| 216 | ||
| 217 | find_ancestor(type: Type) -> Type? => symbol.find_ancestor(type); | |
| 218 | ||
| 219 | freeze() -> Type? => | |
| 220 | let result = symbol.freeze() in | |
| 221 | if result? then result.type else null fi; | |
| 222 | ||
| 223 | gen_class_name(buffer: System.Text.StringBuilder) is | |
| 224 | symbol.gen_class_name(buffer); | |
| 225 | si | |
| 226 | ||
| 227 | gen_type(buffer: System.Text.StringBuilder) is | |
| 228 | symbol.gen_type(buffer); | |
| 229 | si | |
| 230 | ||
| 231 | walk(action: (Type) -> void) is | |
| 232 | action(self); | |
| 233 | si | |
| 234 | ||
| 235 | as_optional() -> Type is | |
| 236 | // A genuine value type carries optionality as NULLABLE[T], | |
| 237 | // never the reference flag. A type variable reports | |
| 238 | // is_value_type spuriously (every GenericArgument does), | |
| 239 | // so exclude it — a `class`-constrained `T?` is flagged. | |
| 240 | if _is_optional \/ (is_value_type /\ !is_type_variable) then | |
| 241 | return self; | |
| 242 | fi | |
| 243 | ||
| 244 | return as_optional_unchecked(); | |
| 245 | si | |
| 246 | ||
| 247 | // Reflected-import variant of `as_optional` that skips the | |
| 248 | // is_value_type / is_type_variable guards. Those guards are | |
| 249 | // about preventing source-side `as_optional()` from flagging a | |
| 250 | // value type as a reference optional. At reflection time the | |
| 251 | // caller already knows the slot was marked by the emitter, | |
| 252 | // which only emits NullableAttribute on reference-`?` slots | |
| 253 | // (Semantic.DotNet.NULLABILITY.needs_attribute filters value | |
| 254 | // types out). Skipping the guards avoids forcing materialization | |
| 255 | // of a lazy TYPE_WRAPPER's symbol during bootstrap — the | |
| 256 | // re-entrant `get_array_type` lookups it triggers would crash | |
| 257 | // before the innate-symbol table is populated. | |
| 258 | as_optional_unchecked() -> Type is | |
| 259 | let result = cast NAMED?(memberwise_clone())!; | |
| 260 | ||
| 261 | result._is_optional = true; | |
| 262 | ||
| 263 | return result; | |
| 264 | si | |
| 265 | ||
| 266 | as_non_optional() -> Type is | |
| 267 | if !_is_optional then | |
| 268 | return self; | |
| 269 | fi | |
| 270 | ||
| 271 | let result = cast NAMED?(memberwise_clone())!; | |
| 272 | ||
| 273 | result._is_optional = false; | |
| 274 | ||
| 275 | return result; | |
| 276 | si | |
| 277 | ||
| 278 | to_string() -> string => | |
| 279 | if _is_optional then | |
| 280 | "{IoC.CONTAINER.instance.name_display.name_for(symbol)}?"; | |
| 281 | else | |
| 282 | IoC.CONTAINER.instance.name_display.name_for(symbol); | |
| 283 | fi; | |
| 284 | si | |
| 285 | si |