Implement Script and Extension matching

Author: Azoy

Sources/_CUnicode/Common/ScriptData.h

@@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "Common/ScriptData.h"
+#include "include/UnicodeData.h"
+
+SWIFT_CC
+uint8_t _swift_stdlib_getScript(uint32_t scalar) {
+  int lowerBoundIndex = 0;
+  int endIndex = SCRIPTS_COUNT;
+  int upperBoundIndex = endIndex - 1;
+  
+  while (upperBoundIndex >= lowerBoundIndex) {
+    int index = lowerBoundIndex + (upperBoundIndex - lowerBoundIndex) / 2;
+    
+    const uint32_t entry = _swift_stdlib_scripts[index];
+    
+    // Shift the enum value out of the scalar.
+    uint32_t lowerBoundScalar = (entry << 11) >> 11;
+    
+    uint32_t upperBoundScalar = 0;
+    
+    // If we're not at the end of the array, the range count is simply the
+    // distance to the next element.
+    if (index != endIndex - 1) {
+      const uint32_t nextEntry = _swift_stdlib_scripts[index + 1];
+      
+      uint32_t nextLower = (nextEntry << 11) >> 11;
+      
+      upperBoundScalar = nextLower - 1;
+    } else {
+      // Otherwise, the range count is the distance to 0x10FFFF
+      upperBoundScalar = 0x10FFFF;
+    }
+    
+    // Shift the scalar out and get the enum value.
+    uint8_t script = entry >> 21;
+    
+    if (scalar >= lowerBoundScalar && scalar <= upperBoundScalar) {
+      return script;
+    }
+    
+    if (scalar > upperBoundScalar) {
+      lowerBoundIndex = index + 1;
+      continue;
+    }
+    
+    if (scalar < lowerBoundScalar) {
+      upperBoundIndex = index - 1;
+      continue;
+    }
+  }
+  
+  // If we make it out of this loop, then it means the scalar was not found at
+  // all in the array. This should never happen because the array represents all
+  // scalars from 0x0 to 0x10FFFF, but if somehow this branch gets reached,
+  // return 255 to indicate a failure.
+  return UINT8_MAX;
+}
+
+SWIFT_CC
+const uint8_t * const _swift_stdlib_getScriptExtensions(uint32_t scalar,
+                                                        uint8_t *count) {
+  intptr_t dataIdx = _swift_stdlib_getScalarBitArrayIdx(scalar,
+                                                _swift_stdlib_script_extensions,
+                                         _swift_stdlib_script_extensions_ranks);
+  
+  // If we don't have an index into the data indices, then this scalar has no
+  // script extensions
+  if (dataIdx == INTPTR_MAX) {
+    return 0;
+  }
+  
+  uint16_t scalarDataIdx = _swift_stdlib_script_extensions_data_indices[dataIdx];
+  *count = scalarDataIdx >> 11;
+  
+  return _swift_stdlib_script_extensions_data + (scalarDataIdx & 0x7FF);
+}

Sources/_CUnicode/UnicodeScalarProps.c

@@ -58,5 +58,14 @@ uint8_t _swift_stdlib_getGraphemeBreakProperty(uint32_t scalar);
 SWIFT_CC
 _Bool _swift_stdlib_isLinkingConsonant(uint32_t scalar);
 
+//===----------------------------------------------------------------------===//
+// Scalar Props
+//===----------------------------------------------------------------------===//
+
+SWIFT_CC
+uint8_t _swift_stdlib_getScript(uint32_t scalar);
+
+SWIFT_CC
+const uint8_t * const _swift_stdlib_getScriptExtensions(uint32_t scalar, uint8_t *count);
 
 #endif // SWIFT_STDLIB_SHIMS_UNICODEDATA_H

Sources/_CUnicode/include/UnicodeData.h

@@ -395,6 +395,21 @@ extension AST.CustomCharacterClass {
 }
 
 // NOTE: Conveniences, though not most performant
+private func consumeScalarScript(
+  _ s: Unicode.Script
+) -> MEProgram<String>.ConsumeFunction {
+  consumeScalar {
+    Unicode.Script($0) == s
+  }
+}
+private func consumeScalarScriptExtension(
+  _ s: Unicode.Script
+) -> MEProgram<String>.ConsumeFunction {
+  consumeScalar {
+    let extensions = Unicode.Script.extensions(for: $0)
+    return extensions.contains(s)
+  }
+}
 private func consumeScalarGC(
   _ gc: Unicode.GeneralCategory
 ) -> MEProgram<String>.ConsumeFunction {
@@ -469,10 +484,10 @@ extension AST.Atom.CharacterProperty {
         return value ? cons : invert(cons)
 
       case .script(let s):
-        throw Unsupported("TODO: Map script: \(s)")
+        return consumeScalarScript(s)
 
       case .scriptExtension(let s):
-        throw Unsupported("TODO: Map script: \(s)")
+        return consumeScalarScriptExtension(s)
 
       case .posix(let p):
         return p.generateConsumer(opts)

Sources/_StringProcessing/ConsumerInterface.swift

@@ -9,6 +9,40 @@
 //
 //===----------------------------------------------------------------------===//
 
+@_silgen_name("_swift_stdlib_getScript")
+func _swift_stdlib_getScript(_: UInt32) -> UInt8
 
-// TODO
+@_silgen_name("_swift_stdlib_getScriptExtensions")
+func _swift_stdlib_getScriptExtensions(
+  _: UInt32,
+  _: UnsafeMutablePointer<UInt8>
+) -> UnsafePointer<UInt8>?
 
+extension Unicode.Script {
+  init(_ scalar: Unicode.Scalar) {
+    let rawValue = _swift_stdlib_getScript(scalar.value)
+    
+    _internalInvariant(rawValue != .max, "Unknown script rawValue: \(rawValue)")
+    
+    self = unsafeBitCast(rawValue, to: Self.self)
+  }
+  
+  static func extensions(for scalar: Unicode.Scalar) -> [Unicode.Script] {
+    var count: UInt8 = 0
+    let pointer = _swift_stdlib_getScriptExtensions(scalar.value, &count)
+    
+    guard let pointer = pointer else {
+      return [Unicode.Script(scalar)]
+    }
+    
+    var result: [Unicode.Script] = []
+    
+    for i in 0 ..< count {
+      let script = pointer[Int(i)]
+      
+      result.append(unsafeBitCast(script, to: Unicode.Script.self))
+    }
+    
+    return result
+  }
+}

Sources/_StringProcessing/Unicode/ScalarProps.swift

@@ -677,34 +677,17 @@ extension RegexTests {
     firstMatchTest(#"\p{ascii}"#, input: "123abcXYZ", match: "1")
     firstMatchTest(#"\p{isAny}"#, input: "123abcXYZ", match: "1")
 
-    // Unfortunately, scripts are not part of stdlib...
-    firstMatchTest(
-      #"\p{sc=grek}"#, input: "123αβγxyz", match: "α",
-      xfail: true)
-    firstMatchTest(
-      #"\p{sc=isGreek}"#, input: "123αβγxyz", match: "α",
-      xfail: true)
-    firstMatchTest(
-      #"\p{Greek}"#, input: "123αβγxyz", match: "α",
-      xfail: true)
-    firstMatchTest(
-      #"\p{isGreek}"#, input: "123αβγxyz", match: "α",
-      xfail: true)
-    firstMatchTest(
-      #"\P{Script=Latn}"#, input: "abcαβγxyz", match: "α",
-      xfail: true)
-    firstMatchTest(
-      #"\p{script=Greek}"#, input: "123αβγxyz", match: "α",
-      xfail: true)
-    firstMatchTest(
-      #"\p{ISscript=isGreek}"#, input: "123αβγxyz", match: "α",
-      xfail: true)
-    firstMatchTest(
-      #"\p{scx=bamum}"#, input: "123ꚠꚡꚢxyz", match: "ꚠ",
-      xfail: true)
-    firstMatchTest(
-      #"\p{ISBAMUM}"#, input: "123ꚠꚡꚢxyz", match: "ꚠ",
-      xfail: true)
+    firstMatchTest(#"\p{sc=grek}"#, input: "123αβγxyz", match: "α")
+    firstMatchTest(#"\p{sc=isGreek}"#, input: "123αβγxyz", match: "α")
+    firstMatchTest(#"\p{Greek}"#, input: "123αβγxyz", match: "α")
+    firstMatchTest(#"\p{isGreek}"#, input: "123αβγxyz", match: "α")
+    firstMatchTest(#"\P{Script=Latn}"#, input: "abcαβγxyz", match: "α")
+    firstMatchTest(#"\p{script=Greek}"#, input: "123αβγxyz", match: "α")
+    firstMatchTest(#"\p{ISscript=isGreek}"#, input: "123αβγxyz", match: "α")
+    firstMatchTest(#"\p{scx=bamum}"#, input: "123ꚠꚡꚢxyz", match: "ꚠ")
+    firstMatchTest(#"\p{ISBAMUM}"#, input: "123ꚠꚡꚢxyz", match: "ꚠ")
+    firstMatchTest(#"\p{Script=Unknown}"#, input: "\u{10FFFF}", match: "\u{10FFFF}")
+    firstMatchTest(#"\p{scx=Gujr}"#, input: "\u{a839}", match: "\u{a839}")
 
     firstMatchTest(#"\p{alpha}"#, input: "123abcXYZ", match: "a")
     firstMatchTest(#"\P{alpha}"#, input: "123abcXYZ", match: "1")