Clean up unicode.py script

2 files changed, 270 insertions, 103 deletions

diff --git a/.gitignore b/.gitignore
index 67e0dd8e795..51f3e722ca7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -36,6 +36,7 @@ __pycache__/
 /src/libcore/unicode/Scripts.txt
 /src/libcore/unicode/SpecialCasing.txt
 /src/libcore/unicode/UnicodeData.txt
+/src/libcore/unicode/downloaded
 /stage[0-9]+/
 /target
 target/
diff --git a/src/libcore/unicode/unicode.py b/src/libcore/unicode/unicode.py
index ae356c3ff44..97c11fb795e 100755
--- a/src/libcore/unicode/unicode.py
+++ b/src/libcore/unicode/unicode.py
@@ -1,35 +1,71 @@
 #!/usr/bin/env python
 
-# This script uses the following Unicode tables:
-# - DerivedCoreProperties.txt
-# - DerivedNormalizationProps.txt
-# - EastAsianWidth.txt
-# - auxiliary/GraphemeBreakProperty.txt
-# - PropList.txt
-# - ReadMe.txt
-# - Scripts.txt
-# - UnicodeData.txt
-#
+"""
+Regenerate Unicode tables (tables.rs).
+"""
+
+# This script uses the Unicode tables as defined
+# in the UnicodeFiles class.
+
 # Since this should not require frequent updates, we just store this
 # out-of-line and check the tables.rs file into git.
 
-import fileinput, re, os, sys, operator, math, datetime
+# Note that the "curl" program is required for operation.
+# This script is compatible with Python 2.7 and 3.x.
+
+import argparse
+import datetime
+import fileinput
+import operator
+import os
+import re
+import textwrap
+import subprocess
+
+from collections import namedtuple
+
+
+# we don't use enum.Enum because of Python 2.7 compatibility
+class UnicodeFiles(object):
+    # ReadMe does not contain any unicode data, we
+    # use it to extract versions.
+    README = "ReadMe.txt"
+
+    DERIVED_CORE_PROPERTIES = "DerivedCoreProperties.txt"
+    DERIVED_NORMALIZATION_PROPS = "DerivedNormalizationProps.txt"
+    SPECIAL_CASING = "SpecialCasing.txt"
+    SCRIPTS = "Scripts.txt"
+    PROPS = "PropList.txt"
+    UNICODE_DATA = "UnicodeData.txt"
+
+
+UnicodeFiles.ALL_FILES = tuple(
+    getattr(UnicodeFiles, name) for name in dir(UnicodeFiles)
+    if not name.startswith("_")
+)
 
-# The directory in which this file resides.
-fdir = os.path.dirname(os.path.realpath(__file__)) + "/"
+# The directory this file is located in.
+THIS_DIR = os.path.dirname(os.path.realpath(__file__))
 
-preamble = '''
+# Where to download the Unicode data.  The downloaded files
+# will be placed in sub-directories named after Unicode version.
+FETCH_DIR = os.path.join(THIS_DIR, "downloaded")
+
+FETCH_URL_LATEST = "ftp://ftp.unicode.org/Public/UNIDATA/{filename}"
+FETCH_URL_VERSION = "ftp://ftp.unicode.org/Public/{version}/ucd/{filename}"
+
+PREAMBLE = """\
 // NOTE: The following code was generated by "./unicode.py", do not edit directly
 
 #![allow(missing_docs, non_upper_case_globals, non_snake_case)]
 
 use unicode::version::UnicodeVersion;
 use unicode::bool_trie::{{BoolTrie, SmallBoolTrie}};
-'''.format(year = datetime.datetime.now().year)
+""".format(year=datetime.datetime.now().year)
 
 # Mapping taken from Table 12 from:
 # http://www.unicode.org/reports/tr44/#General_Category_Values
-expanded_categories = {
+EXPANDED_CATEGORIES = {
     'Lu': ['LC', 'L'], 'Ll': ['LC', 'L'], 'Lt': ['LC', 'L'],
     'Lm': ['L'], 'Lo': ['L'],
     'Mn': ['M'], 'Mc': ['M'], 'Me': ['M'],
@@ -42,22 +78,101 @@ expanded_categories = {
 }
 
 # these are the surrogate codepoints, which are not valid rust characters
-surrogate_codepoints = (0xd800, 0xdfff)
+SURROGATE_CODEPOINTS = (0xd800, 0xdfff)
+
+UnicodeData = namedtuple(
+    "UnicodeData", ("canon_decomp", "compat_decomp", "gencats", "combines",
+                    "to_upper", "to_lower", "to_title", )
+)
+
+UnicodeVersion = namedtuple(
+    "UnicodeVersion", ("major", "minor", "micro", "as_str")
+)
+
+
+def fetch_files(version=None):
+    """
+    Fetch all the Unicode files from unicode.org
+
+    :param version: The desired Unicode version, as string.
+        (If None, defaults to latest final release available).
+    :return: The version downloaded (UnicodeVersion object).
+    """
+    have_version = should_skip_fetch(version)
+    if have_version:
+        return have_version
+
+    if version:
+        # check if the desired version exists on the server
+        get_fetch_url = lambda name: FETCH_URL_VERSION.format(version=version, filename=name)
+    else:
+        # extract the latest version
+        get_fetch_url = lambda name: FETCH_URL_LATEST.format(filename=name)
+
+    readme_url = get_fetch_url(UnicodeFiles.README)
+
+    print("Fetching: {}".format(readme_url))
+    readme_content = subprocess.check_output(("curl", readme_url))
+
+    unicode_version = parse_unicode_version(
+        str(readme_content, "utf8")
+    )
+
+    download_dir = os.path.join(FETCH_DIR, unicode_version.as_str)
+    if not os.path.exists(download_dir):
+        # for 2.7 compat, we don't use exist_ok=True
+        os.makedirs(download_dir)
+
+    for filename in UnicodeFiles.ALL_FILES:
+        file_path = os.path.join(download_dir, filename)
+
+        if filename == UnicodeFiles.README:
+            with open(file_path, "wb") as fd:
+                fd.write(readme_content)
+        elif not os.path.exists(file_path):
+            url = get_fetch_url(filename)
+            print("Fetching: {}".format(url))
+            subprocess.check_call(("curl", "-o", file_path, url))
+
+    return unicode_version
+
+
+def should_skip_fetch(version):
+    if not version:
+        # should always check latest version
+        return False
+
+    fetch_dir = os.path.join(FETCH_DIR, version)
+
+    for filename in UnicodeFiles.ALL_FILES:
+        file_path = os.path.join(fetch_dir, filename)
+
+        if not os.path.exists(file_path):
+            return False
+
+    with open(os.path.join(fetch_dir, UnicodeFiles.README)) as fd:
+        return parse_unicode_version(fd.read())
+
+
+def parse_unicode_version(readme_content):
+    # "raw string" is necessary for \d not being treated as escape char
+    # (for the sake of compat with future Python versions)
+    # see: https://docs.python.org/3.6/whatsnew/3.6.html#deprecated-python-behavior
+    pattern = r"for Version (\d+)\.(\d+)\.(\d+) of the Unicode"
+    groups = re.search(pattern, readme_content).groups()
+
+    return UnicodeVersion(*map(int, groups), as_str=".".join(groups))
+
 
-def fetch(f):
-    path = fdir + os.path.basename(f)
-    if not os.path.exists(path):
-        os.system("curl -o {0}{1} ftp://ftp.unicode.org/Public/UNIDATA/{1}".format(fdir, f))
+def get_unicode_file_path(unicode_version, filename):
+    return os.path.join(FETCH_DIR, unicode_version.as_str, filename)
 
-    if not os.path.exists(path):
-        sys.stderr.write("cannot load %s" % f)
-        exit(1)
 
 def is_surrogate(n):
-    return surrogate_codepoints[0] <= n <= surrogate_codepoints[1]
+    return SURROGATE_CODEPOINTS[0] <= n <= SURROGATE_CODEPOINTS[1]
 
-def load_unicode_data(f):
-    fetch(f)
+
+def load_unicode_data(file_path):
     gencats = {}
     to_lower = {}
     to_upper = {}
@@ -68,8 +183,8 @@ def load_unicode_data(f):
 
     udict = {}
     range_start = -1
-    for line in fileinput.input(fdir + f):
-        data = line.split(';')
+    for line in fileinput.input(file_path):
+        data = line.split(";")
         if len(data) != 15:
             continue
         cp = int(data[0], 16)
@@ -104,7 +219,7 @@ def load_unicode_data(f):
 
         # store decomposition, if given
         if decomp != "":
-            if decomp.startswith('<'):
+            if decomp.startswith("<"):
                 seq = []
                 for i in decomp.split()[1:]:
                     seq.append(int(i, 16))
@@ -116,7 +231,7 @@ def load_unicode_data(f):
                 canon_decomp[code] = seq
 
         # place letter in categories as appropriate
-        for cat in [gencat, "Assigned"] + expanded_categories.get(gencat, []):
+        for cat in [gencat, "Assigned"] + EXPANDED_CATEGORIES.get(gencat, []):
             if cat not in gencats:
                 gencats[cat] = []
             gencats[cat].append(code)
@@ -136,12 +251,15 @@ def load_unicode_data(f):
     gencats = group_cats(gencats)
     combines = to_combines(group_cats(combines))
 
-    return (canon_decomp, compat_decomp, gencats, combines, to_upper, to_lower, to_title)
+    return UnicodeData(
+        canon_decomp, compat_decomp, gencats, combines, to_upper,
+        to_lower, to_title,
+    )
+
 
-def load_special_casing(f, to_upper, to_lower, to_title):
-    fetch(f)
-    for line in fileinput.input(fdir + f):
-        data = line.split('#')[0].split(';')
+def load_special_casing(file_path, unicode_data):
+    for line in fileinput.input(file_path):
+        data = line.split("#")[0].split(";")
         if len(data) == 5:
             code, lower, title, upper, _comment = data
         elif len(data) == 6:
@@ -155,7 +273,9 @@ def load_special_casing(f, to_upper, to_lower, to_title):
         title = title.strip()
         upper = upper.strip()
         key = int(code, 16)
-        for (map_, values) in [(to_lower, lower), (to_upper, upper), (to_title, title)]:
+        for (map_, values) in ((unicode_data.to_lower, lower),
+                               (unicode_data.to_upper, upper),
+                               (unicode_data.to_title, title)):
             if values != code:
                 values = [int(i, 16) for i in values.split()]
                 for _ in range(len(values), 3):
@@ -163,12 +283,14 @@ def load_special_casing(f, to_upper, to_lower, to_title):
                 assert len(values) == 3
                 map_[key] = values
 
+
 def group_cats(cats):
     cats_out = {}
     for cat in cats:
         cats_out[cat] = group_cat(cats[cat])
     return cats_out
 
+
 def group_cat(cat):
     cat_out = []
     letters = sorted(set(cat))
@@ -185,6 +307,7 @@ def group_cat(cat):
     cat_out.append((cur_start, cur_end))
     return cat_out
 
+
 def ungroup_cat(cat):
     cat_out = []
     for (lo, hi) in cat:
@@ -193,21 +316,24 @@ def ungroup_cat(cat):
             lo += 1
     return cat_out
 
+
 def gen_unassigned(assigned):
     assigned = set(assigned)
     return ([i for i in range(0, 0xd800) if i not in assigned] +
             [i for i in range(0xe000, 0x110000) if i not in assigned])
 
+
 def to_combines(combs):
     combs_out = []
     for comb in combs:
         for (lo, hi) in combs[comb]:
             combs_out.append((lo, hi, comb))
-    combs_out.sort(key=lambda comb: comb[0])
+    combs_out.sort(key=lambda c: c[0])
     return combs_out
 
+
 def format_table_content(f, content, indent):
-    line = " "*indent
+    line = " " * indent
     first = True
     for chunk in content.split(","):
         if len(line) + len(chunk) < 98:
@@ -218,16 +344,19 @@ def format_table_content(f, content, indent):
             first = False
         else:
             f.write(line + ",\n")
-            line = " "*indent + chunk
+            line = " " * indent + chunk
     f.write(line)
 
-def load_properties(f, interestingprops):
-    fetch(f)
+
+def load_properties(file_path, interestingprops):
     props = {}
-    re1 = re.compile("^ *([0-9A-F]+) *; *(\w+)")
-    re2 = re.compile("^ *([0-9A-F]+)\.\.([0-9A-F]+) *; *(\w+)")
+    # "raw string" is necessary for \w not to be treated as escape char
+    # (for the sake of compat with future Python versions)
+    # see: https://docs.python.org/3.6/whatsnew/3.6.html#deprecated-python-behavior
+    re1 = re.compile(r"^ *([0-9A-F]+) *; *(\w+)")
+    re2 = re.compile(r"^ *([0-9A-F]+)\.\.([0-9A-F]+) *; *(\w+)")
 
-    for line in fileinput.input(fdir + os.path.basename(f)):
+    for line in fileinput.input(file_path):
         prop = None
         d_lo = 0
         d_hi = 0
@@ -258,10 +387,12 @@ def load_properties(f, interestingprops):
 
     return props
 
+
 def escape_char(c):
     return "'\\u{%x}'" % c if c != 0 else "'\\0'"
 
-def emit_table(f, name, t_data, t_type = "&[(char, char)]", is_pub=True,
+
+def emit_table(f, name, t_data, t_type="&[(char, char)]", is_pub=True,
         pfun=lambda x: "(%s,%s)" % (escape_char(x[0]), escape_char(x[1]))):
     pub_string = ""
     if is_pub:
@@ -277,6 +408,7 @@ def emit_table(f, name, t_data, t_type = "&[(char, char)]", is_pub=True,
     format_table_content(f, data, 8)
     f.write("\n    ];\n\n")
 
+
 def compute_trie(rawdata, chunksize):
     root = []
     childmap = {}
@@ -288,10 +420,11 @@ def compute_trie(rawdata, chunksize):
             childmap[child] = len(childmap)
             child_data.extend(data)
         root.append(childmap[child])
-    return (root, child_data)
+    return root, child_data
+
 
 def emit_bool_trie(f, name, t_data, is_pub=True):
-    CHUNK = 64
+    chunk_size = 64
     rawdata = [False] * 0x110000
     for (lo, hi) in t_data:
         for cp in range(lo, hi + 1):
@@ -299,7 +432,7 @@ def emit_bool_trie(f, name, t_data, is_pub=True):
 
     # convert to bitmap chunks of 64 bits each
     chunks = []
-    for i in range(0x110000 // CHUNK):
+    for i in range(0x110000 // chunk_size):
         chunk = 0
         for j in range(64):
             if rawdata[i * 64 + j]:
@@ -311,12 +444,12 @@ def emit_bool_trie(f, name, t_data, is_pub=True):
         pub_string = "pub "
     f.write("    %sconst %s: &super::BoolTrie = &super::BoolTrie {\n" % (pub_string, name))
     f.write("        r1: [\n")
-    data = ','.join('0x%016x' % chunk for chunk in chunks[0:0x800 // CHUNK])
+    data = ','.join('0x%016x' % chunk for chunk in chunks[0:0x800 // chunk_size])
     format_table_content(f, data, 12)
     f.write("\n        ],\n")
 
     # 0x800..0x10000 trie
-    (r2, r3) = compute_trie(chunks[0x800 // CHUNK : 0x10000 // CHUNK], 64 // CHUNK)
+    (r2, r3) = compute_trie(chunks[0x800 // chunk_size : 0x10000 // chunk_size], 64 // chunk_size)
     f.write("        r2: [\n")
     data = ','.join(str(node) for node in r2)
     format_table_content(f, data, 12)
@@ -327,7 +460,7 @@ def emit_bool_trie(f, name, t_data, is_pub=True):
     f.write("\n        ],\n")
 
     # 0x10000..0x110000 trie
-    (mid, r6) = compute_trie(chunks[0x10000 // CHUNK : 0x110000 // CHUNK], 64 // CHUNK)
+    (mid, r6) = compute_trie(chunks[0x10000 // chunk_size : 0x110000 // chunk_size], 64 // chunk_size)
     (r4, r5) = compute_trie(mid, 64)
     f.write("        r4: [\n")
     data = ','.join(str(node) for node in r4)
@@ -344,6 +477,7 @@ def emit_bool_trie(f, name, t_data, is_pub=True):
 
     f.write("    };\n\n")
 
+
 def emit_small_bool_trie(f, name, t_data, is_pub=True):
     last_chunk = max(hi // 64 for (lo, hi) in t_data)
     n_chunks = last_chunk + 1
@@ -374,6 +508,7 @@ def emit_small_bool_trie(f, name, t_data, is_pub=True):
 
     f.write("    };\n\n")
 
+
 def emit_property_module(f, mod, tbl, emit):
     f.write("pub mod %s {\n" % mod)
     for cat in sorted(emit):
@@ -389,7 +524,8 @@ def emit_property_module(f, mod, tbl, emit):
             f.write("    }\n\n")
     f.write("}\n\n")
 
-def emit_conversions_module(f, to_upper, to_lower, to_title):
+
+def emit_conversions_module(f, unicode_data):
     f.write("pub mod conversions {")
     f.write("""
     pub fn to_lower(c: char) -> [char; 3] {
@@ -414,74 +550,104 @@ def emit_conversions_module(f, to_upper, to_lower, to_title):
     t_type = "&[(char, [char; 3])]"
     pfun = lambda x: "(%s,[%s,%s,%s])" % (
         escape_char(x[0]), escape_char(x[1][0]), escape_char(x[1][1]), escape_char(x[1][2]))
-    emit_table(f, "to_lowercase_table",
-        sorted(to_lower.items(), key=operator.itemgetter(0)),
-        is_pub=False, t_type = t_type, pfun=pfun)
-    emit_table(f, "to_uppercase_table",
-        sorted(to_upper.items(), key=operator.itemgetter(0)),
-        is_pub=False, t_type = t_type, pfun=pfun)
-    f.write("}\n\n")
 
-def emit_norm_module(f, canon, compat, combine, norm_props):
-    canon_keys = sorted(canon.keys())
+    emit_table(f,
+               name="to_lowercase_table",
+               t_data=sorted(unicode_data.to_lower.items(), key=operator.itemgetter(0)),
+               t_type=t_type,
+               is_pub=False,
+               pfun=pfun)
 
-    compat_keys = sorted(compat.keys())
+    emit_table(f,
+               name="to_uppercase_table",
+               t_data=sorted(unicode_data.to_upper.items(), key=operator.itemgetter(0)),
+               t_type=t_type,
+               is_pub=False,
+               pfun=pfun)
+
+    f.write("}\n")
+
+
+def emit_norm_module(f, unicode_data, norm_props):
+    canon_keys = sorted(unicode_data.canon_decomp.keys())
 
     canon_comp = {}
     comp_exclusions = norm_props["Full_Composition_Exclusion"]
     for char in canon_keys:
         if any(lo <= char <= hi for lo, hi in comp_exclusions):
             continue
-        decomp = canon[char]
+        decomp = unicode_data.canon_decomp[char]
         if len(decomp) == 2:
             if decomp[0] not in canon_comp:
                 canon_comp[decomp[0]] = []
-            canon_comp[decomp[0]].append( (decomp[1], char) )
-    canon_comp_keys = sorted(canon_comp.keys())
+            canon_comp[decomp[0]].append((decomp[1], char))
 
-if __name__ == "__main__":
-    r = fdir + "tables.rs"
-    if os.path.exists(r):
-        os.remove(r)
-    with open(r, "w") as rf:
+
+def parse_args():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("-v", "--version", default=None, type=str,
+                        help="Unicode version to use (if not specified,"
+                             " defaults to latest available final release).")
+
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    unicode_version = fetch_files(args.version)
+    print("Using Unicode version: {}".format(unicode_version.as_str))
+
+    tables_rs_path = os.path.join(THIS_DIR, "tables.rs")
+    if os.path.exists(tables_rs_path):
+        os.remove(tables_rs_path)
+
+    with open(tables_rs_path, "w") as rf:
         # write the file's preamble
-        rf.write(preamble)
-
-        # download and parse all the data
-        fetch("ReadMe.txt")
-        with open(fdir + "ReadMe.txt") as readme:
-            pattern = "for Version (\d+)\.(\d+)\.(\d+) of the Unicode"
-            unicode_version = re.search(pattern, readme.read()).groups()
-        rf.write("""
-/// The version of [Unicode](http://www.unicode.org/) that the Unicode parts of
-/// `char` and `str` methods are based on.
-#[unstable(feature = "unicode_version", issue = "49726")]
-pub const UNICODE_VERSION: UnicodeVersion = UnicodeVersion {
-    major: %s,
-    minor: %s,
-    micro: %s,
-    _priv: (),
-};
-""" % unicode_version)
-        (canon_decomp, compat_decomp, gencats, combines,
-                to_upper, to_lower, to_title) = load_unicode_data("UnicodeData.txt")
-        load_special_casing("SpecialCasing.txt", to_upper, to_lower, to_title)
+        rf.write(PREAMBLE)
+
+        unicode_version_notice = textwrap.dedent("""
+        /// The version of [Unicode](http://www.unicode.org/) that the Unicode parts of
+        /// `char` and `str` methods are based on.
+        #[unstable(feature = "unicode_version", issue = "49726")]
+        pub const UNICODE_VERSION: UnicodeVersion = UnicodeVersion {{
+            major: {version.major},
+            minor: {version.minor},
+            micro: {version.micro},
+            _priv: (),
+        }};
+        """).format(version=unicode_version)
+        rf.write(unicode_version_notice)
+
+        get_path = lambda f: get_unicode_file_path(unicode_version, f)
+
+        unicode_data = load_unicode_data(get_path(UnicodeFiles.UNICODE_DATA))
+        load_special_casing(get_path(UnicodeFiles.SPECIAL_CASING), unicode_data)
+
         want_derived = ["XID_Start", "XID_Continue", "Alphabetic", "Lowercase", "Uppercase",
                         "Cased", "Case_Ignorable", "Grapheme_Extend"]
-        derived = load_properties("DerivedCoreProperties.txt", want_derived)
-        scripts = load_properties("Scripts.txt", [])
-        props = load_properties("PropList.txt",
-                ["White_Space", "Join_Control", "Noncharacter_Code_Point", "Pattern_White_Space"])
-        norm_props = load_properties("DerivedNormalizationProps.txt",
-                     ["Full_Composition_Exclusion"])
+        derived = load_properties(get_path(UnicodeFiles.DERIVED_CORE_PROPERTIES), want_derived)
+
+        # TODO scripts not used?
+        scripts = load_properties(get_path(UnicodeFiles.SCRIPTS), [])
+        props = load_properties(get_path(UnicodeFiles.PROPS),
+                                ["White_Space", "Join_Control", "Noncharacter_Code_Point",
+                                 "Pattern_White_Space"])
+        norm_props = load_properties(get_path(UnicodeFiles.DERIVED_NORMALIZATION_PROPS),
+                                     ["Full_Composition_Exclusion"])
 
         # category tables
-        for (name, cat, pfuns) in ("general_category", gencats, ["N", "Cc"]), \
-                                  ("derived_property", derived, want_derived), \
-                                  ("property", props, ["White_Space", "Pattern_White_Space"]):
+        for (name, cat, pfuns) in (("general_category", unicode_data.gencats, ["N", "Cc"]),
+                                   ("derived_property", derived, want_derived),
+                                   ("property", props, ["White_Space", "Pattern_White_Space"])):
             emit_property_module(rf, name, cat, pfuns)
 
         # normalizations and conversions module
-        emit_norm_module(rf, canon_decomp, compat_decomp, combines, norm_props)
-        emit_conversions_module(rf, to_upper, to_lower, to_title)
+        emit_norm_module(rf, unicode_data, norm_props)
+        emit_conversions_module(rf, unicode_data)
+
     print("Regenerated tables.rs.")
+
+
+if __name__ == "__main__":
+    main()