Add support to libcore for encoded-in-rust unicode character properties, at least. Add script to compute them from unicode.org.

1 files changed, 172 insertions, 0 deletions

diff --git a/src/etc/unicode.py b/src/etc/unicode.py
new file mode 100755
index 00000000000..f52335a9cab
--- /dev/null
+++ b/src/etc/unicode.py
@@ -0,0 +1,172 @@
+#!/usr/bin/env python
+
+# This digests UnicodeData.txt and DerivedCoreProperties.txt and emits rust
+# code covering the core properties. Since this is a pretty rare event we
+# just store this out-of-line and check the unicode.rs file into git.
+#
+# The emitted code is "the minimum we think is necessary for libcore", that
+# is, to support basic operations of the compiler and "most nontrivial rust
+# programs". It is not meant to be a complete implementation of unicode.
+# For that we recommend you use a proper binding to libicu.
+
+import fileinput, re, os, sys
+
+
+def fetch(f):
+    if not os.path.exists(f):
+        os.system("curl -O http://www.unicode.org/Public/UNIDATA/%s"
+                  % f)
+
+    if not os.path.exists(f):
+        sys.stderr.write("cannot load %s" % f)
+        exit(1)
+
+
+def load_general_categories(f):
+    fetch(f)
+    gencats = {}
+    curr_cat = ""
+    c_lo = 0
+    c_hi = 0
+    for line in fileinput.input(f):
+        fields = line.split(";")
+        if len(fields) != 15:
+            continue
+        [code, name, gencat, combine, bidi,
+         decomp, deci, digit, num, mirror,
+         old, iso, upcase, lowcsae, titlecase ] = fields
+
+        code = int(code, 16)
+
+        if curr_cat == "":
+            curr_cat = gencat
+            c_lo = code
+            c_hi = code
+
+        if curr_cat == gencat:
+            c_hi = code
+        else:
+            if curr_cat not in gencats:
+                gencats[curr_cat] = []
+
+            gencats[curr_cat].append((c_lo, c_hi))
+            curr_cat = gencat
+            c_lo = code
+            c_hi = code
+    return gencats
+
+
+def load_derived_core_properties(f):
+    fetch(f)
+    derivedprops = {}
+    interestingprops = ["XID_Start", "XID_Continue", "Alphabetic"]
+    re1 = re.compile("^([0-9A-F]+) +; (\w+)")
+    re2 = re.compile("^([0-9A-F]+)\.\.([0-9A-F]+) +; (\w+)")
+
+    for line in fileinput.input(f):
+        prop = None
+        d_lo = 0
+        d_hi = 0
+        m = re1.match(line)
+        if m:
+            d_lo = m.group(1)
+            d_hi = m.group(1)
+            prop = m.group(2)
+        else:
+            m = re2.match(line)
+            if m:
+                d_lo = m.group(1)
+                d_hi = m.group(2)
+                prop = m.group(3)
+            else:
+                continue
+        if prop not in interestingprops:
+            continue
+        d_lo = int(d_lo, 16)
+        d_hi = int(d_hi, 16)
+        if prop not in derivedprops:
+            derivedprops[prop] = []
+        derivedprops[prop].append((d_lo, d_hi))
+    return derivedprops
+
+def escape_char(c):
+    if c <= 0xff:
+        return "'\\x%2.2x'" % c
+    if c <= 0xffff:
+        return "'\\u%4.4x'" % c
+    return "'\\U%8.8x'" % c
+
+def emit_rust_module(f, mod, tbl):
+    f.write("mod %s {\n" % mod)
+    keys = tbl.keys()
+    keys.sort()
+    for cat in keys:
+        f.write("    pure fn %s(c: char) -> bool {\n" % cat)
+        f.write("        ret alt c {\n")
+        prefix = ' '
+        for pair in tbl[cat]:
+            if pair[0] == pair[1]:
+                f.write("            %c %s\n" %
+                        (prefix, escape_char(pair[0])))
+            else:
+                f.write("            %c %s to %s\n" %
+                        (prefix,
+                         escape_char(pair[0]),
+                         escape_char(pair[1])))
+            prefix = '|'
+        f.write("              { true }\n")
+        f.write("            _ { false }\n")
+        f.write("        };\n")
+        f.write("    }\n\n")
+    f.write("}\n")
+
+
+def emit_cpp_module(f, mod, tbl):
+    keys = tbl.keys()
+    keys.sort()
+
+    for cat in keys:
+
+        singles = []
+        ranges = []
+
+        for pair in tbl[cat]:
+            if pair[0] == pair[1]:
+                singles.append(pair[0])
+            else:
+                ranges.append(pair)
+
+        f.write("bool %s_%s(unsigned c) {\n" % (mod, cat))
+        for pair in ranges:
+            f.write("    if (0x%x <= c && c <= 0x%x) { return true; }\n"
+                    % pair)
+        if len(singles) > 0:
+            f.write("    switch (c) {\n");
+            for single in singles:
+                f.write("      case 0x%x:\n" % single)
+            f.write("        return true;\n");
+            f.write("      default:\n");
+            f.write("        return false;\n");
+            f.write("    }\n")
+        f.write("return false;\n")
+        f.write("}\n\n")
+
+
+def emit_module(rf, cf, mod, tbl):
+    emit_rust_module(rf, mod, tbl)
+    emit_cpp_module(cf, mod, tbl)
+
+r = "unicode.rs"
+c = "unicode.cpp"
+for i in [r, c]:
+    if os.path.exists(i):
+        os.remove(i);
+
+rf = open(r, "w")
+cf = open(c, "w")
+
+emit_module(rf, cf, "general_category",
+            load_general_categories("UnicodeData.txt"))
+
+emit_module(rf, cf, "derived_property",
+            load_derived_core_properties("DerivedCoreProperties.txt"))