idna: combine two tables

idna/src/make_uts46_mapping_table.py

@@ -150,27 +150,22 @@ def merge_single_char_ranges(ranges):
 
 optimized_ranges = list(merge_single_char_ranges(optimized_ranges))
 
-
-print("static TABLE: &[char] = &[")
-
-for ranges in optimized_ranges:
-    print("    '%s'," % escape_char(char(ranges[0][0])))
-
-print("];\n")
-
-print("static INDEX_TABLE: &[u16] = &[")
-
 SINGLE_MARKER = 1 << 15
 
+print("static TABLE: &[(char, u16)] = &[")
+
 offset = 0
 for ranges in optimized_ranges:
     assert offset < SINGLE_MARKER
 
     block_len = len(ranges)
     single = SINGLE_MARKER if block_len == 1 else 0
-    print("    %s," % (offset | single))
+    index = offset | single
     offset += block_len
 
+    start = escape_char(char(ranges[0][0]))
+    print("    ('%s', %s)," % (start, index))
+
 print("];\n")
 
 print("static MAPPING_TABLE: &[Mapping] = &[")

idna/src/uts46.rs

@@ -51,21 +51,21 @@ enum Mapping {
 }
 
 fn find_char(codepoint: char) -> &'static Mapping {
-    let idx = match TABLE.binary_search(&codepoint) {
+    let idx = match TABLE.binary_search_by_key(&codepoint, |&val| val.0) {
         Ok(idx) => idx,
         Err(idx) => idx - 1,
     };
 
     const SINGLE_MARKER: u16 = 1 << 15;
 
-    let x = INDEX_TABLE[idx];
+    let (base, x) = TABLE[idx];
     let single = (x & SINGLE_MARKER) != 0;
     let offset = !SINGLE_MARKER & x;
 
     if single {
         &MAPPING_TABLE[offset as usize]
     } else {
-        &MAPPING_TABLE[(offset + (codepoint as u16 - TABLE[idx] as u16)) as usize]
+        &MAPPING_TABLE[(offset + (codepoint as u16 - base as u16)) as usize]
     }
 }