Vendor things

third-party/vendor/unicode-normalization/src/lookups.rs

@@ -0,0 +1,138 @@
+// Copyright 2019 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Lookups of unicode properties using minimal perfect hashing.
+
+use crate::perfect_hash::mph_lookup;
+use crate::tables::*;
+
+/// Look up the canonical combining class for a codepoint.
+///
+/// The value returned is as defined in the Unicode Character Database.
+pub fn canonical_combining_class(c: char) -> u8 {
+    mph_lookup(
+        c.into(),
+        CANONICAL_COMBINING_CLASS_SALT,
+        CANONICAL_COMBINING_CLASS_KV,
+        u8_lookup_fk,
+        u8_lookup_fv,
+        0,
+    )
+}
+
+pub(crate) fn composition_table(c1: char, c2: char) -> Option<char> {
+    if c1 < '\u{10000}' && c2 < '\u{10000}' {
+        mph_lookup(
+            (c1 as u32) << 16 | (c2 as u32),
+            COMPOSITION_TABLE_SALT,
+            COMPOSITION_TABLE_KV,
+            pair_lookup_fk,
+            pair_lookup_fv_opt,
+            None,
+        )
+    } else {
+        composition_table_astral(c1, c2)
+    }
+}
+
+pub(crate) fn canonical_fully_decomposed(c: char) -> Option<&'static [char]> {
+    mph_lookup(
+        c.into(),
+        CANONICAL_DECOMPOSED_SALT,
+        CANONICAL_DECOMPOSED_KV,
+        pair_lookup_fk,
+        pair_lookup_fv_opt,
+        None,
+    )
+    .map(|(start, len)| &CANONICAL_DECOMPOSED_CHARS[start as usize..][..len as usize])
+}
+
+pub(crate) fn compatibility_fully_decomposed(c: char) -> Option<&'static [char]> {
+    mph_lookup(
+        c.into(),
+        COMPATIBILITY_DECOMPOSED_SALT,
+        COMPATIBILITY_DECOMPOSED_KV,
+        pair_lookup_fk,
+        pair_lookup_fv_opt,
+        None,
+    )
+    .map(|(start, len)| &COMPATIBILITY_DECOMPOSED_CHARS[start as usize..][..len as usize])
+}
+
+pub(crate) fn cjk_compat_variants_fully_decomposed(c: char) -> Option<&'static [char]> {
+    mph_lookup(
+        c.into(),
+        CJK_COMPAT_VARIANTS_DECOMPOSED_SALT,
+        CJK_COMPAT_VARIANTS_DECOMPOSED_KV,
+        pair_lookup_fk,
+        pair_lookup_fv_opt,
+        None,
+    )
+    .map(|(start, len)| &CJK_COMPAT_VARIANTS_DECOMPOSED_CHARS[start as usize..][..len as usize])
+}
+
+/// Return whether the given character is a combining mark (`General_Category=Mark`)
+pub fn is_combining_mark(c: char) -> bool {
+    mph_lookup(
+        c.into(),
+        COMBINING_MARK_SALT,
+        COMBINING_MARK_KV,
+        bool_lookup_fk,
+        bool_lookup_fv,
+        false,
+    )
+}
+
+pub fn stream_safe_trailing_nonstarters(c: char) -> usize {
+    mph_lookup(
+        c.into(),
+        TRAILING_NONSTARTERS_SALT,
+        TRAILING_NONSTARTERS_KV,
+        u8_lookup_fk,
+        u8_lookup_fv,
+        0,
+    ) as usize
+}
+
+/// Extract the key in a 24 bit key and 8 bit value packed in a u32.
+#[inline]
+fn u8_lookup_fk(kv: u32) -> u32 {
+    kv >> 8
+}
+
+/// Extract the value in a 24 bit key and 8 bit value packed in a u32.
+#[inline]
+fn u8_lookup_fv(kv: u32) -> u8 {
+    (kv & 0xff) as u8
+}
+
+/// Extract the key for a boolean lookup.
+#[inline]
+fn bool_lookup_fk(kv: u32) -> u32 {
+    kv
+}
+
+/// Extract the value for a boolean lookup.
+#[inline]
+fn bool_lookup_fv(_kv: u32) -> bool {
+    true
+}
+
+/// Extract the key in a pair.
+#[inline]
+fn pair_lookup_fk<T>(kv: (u32, T)) -> u32 {
+    kv.0
+}
+
+/// Extract the value in a pair, returning an option.
+#[inline]
+fn pair_lookup_fv_opt<T>(kv: (u32, T)) -> Option<T> {
+    Some(kv.1)
+}