[feaLib] Implement table head with FontRevision statement

Lib/fontTools/feaLib/ast.py

@@ -302,6 +302,15 @@ class IgnoreSubstitutionRule(Statement):
         self.prefix, self.glyphs, self.suffix = (prefix, glyphs, suffix)
 
 
+class FontRevisionStatement(Statement):
+    def __init__(self, location, revision):
+        Statement.__init__(self, location)
+        self.revision = revision
+
+    def build(self, builder):
+        builder.set_font_revision(self.location, self.revision)
+
+
 class LigatureCaretByIndexStatement(Statement):
     def __init__(self, location, glyphs, carets):
         Statement.__init__(self, location)

Lib/fontTools/feaLib/builder.py

@@ -33,6 +33,8 @@ class Builder(object):
         # for feature 'aalt'
         self.aalt_features_ = []  # [(location, featureName)*], for 'aalt'
         self.aalt_location_ = None
+        # for table 'head'
+        self.fontRevision_ = None  # 2.71
         # for table 'GDEF'
         self.attachPoints_ = {}  # "a" --> {3, 7}
         self.ligatureCaretByIndex_ = {}  # "f_f_i" --> {3, 7}
@@ -46,6 +48,7 @@ class Builder(object):
         self.parseTree = Parser(self.featurefile_path).parse()
         self.parseTree.build(self)
         self.build_feature_aalt_()
+        self.build_head()
         for tag in ('GPOS', 'GSUB'):
             table = self.makeTable(tag)
             if (table.ScriptList.ScriptCount > 0 or
@@ -142,6 +145,16 @@ class Builder(object):
         self.end_feature()
         self.lookups_.extend(old_lookups)
 
+    def build_head(self):
+        if not self.fontRevision_:
+            return
+        table = self.font.get("head")
+        if not table:  # this only happens for unit tests
+            table = self.font["head"] = getTableClass("head")()
+            table.decompile(b"\0" * 54, self.font)
+            table.tableVersion = 1.0
+        table.fontRevision = self.fontRevision_
+
     def buildGDEF(self):
         gdef = otTables.GDEF()
         gdef.GlyphClassDef = self.buildGDEFGlyphClassDef_()
@@ -408,6 +421,9 @@ class Builder(object):
         lookup = self.named_lookups_[lookup_name]
         self.add_lookup_to_feature_(lookup, self.cur_feature_name_)
 
+    def set_font_revision(self, location, revision):
+        self.fontRevision_ = revision
+
     def set_language(self, location, language, include_default, required):
         assert(len(language) == 4)
         if self.cur_lookup_name_:

Lib/fontTools/feaLib/builder_test.py

@@ -80,7 +80,7 @@ class BuilderTest(unittest.TestCase):
 
     def expect_ttx(self, font, expected_ttx):
         path = self.temp_path(suffix=".ttx")
-        font.saveXML(path, quiet=True, tables=['GDEF', 'GSUB', 'GPOS'])
+        font.saveXML(path, quiet=True, tables=['head', 'GDEF', 'GSUB', 'GPOS'])
         actual = self.read_ttx(path)
         expected = self.read_ttx(expected_ttx)
         if actual != expected:
@@ -168,7 +168,7 @@ class BuilderTest(unittest.TestCase):
 
     def test_spec(self):
         for name in ("4h1 5d1 5d2 5fi1 5fi2 5fi3 5fi4 5h1 "
-                     "6d2 6e 6f 6h_ii 8a 9b").split():
+                     "6d2 6e 6f 6h_ii 8a 9b 9c1 9c2 9c3").split():
             font = makeTTFont()
             addOpenTypeFeatures(self.getpath("spec%s.fea" % name), font)
             self.expect_ttx(font, self.getpath("spec%s.ttx" % name))

Lib/fontTools/feaLib/lexer.py

@@ -8,6 +8,7 @@ import os
 
 class Lexer(object):
     NUMBER = "NUMBER"
+    FLOAT = "FLOAT"
     STRING = "STRING"
     NAME = "NAME"
     FILENAME = "FILENAME"
@@ -123,11 +124,19 @@ class Lexer(object):
             return (Lexer.NUMBER, int(text[start:self.pos_], 16), location)
         if cur_char in Lexer.CHAR_DIGIT_:
             self.scan_over_(Lexer.CHAR_DIGIT_)
-            return (Lexer.NUMBER, int(text[start:self.pos_], 10), location)
+            if next_char != ".":
+                return (Lexer.NUMBER, int(text[start:self.pos_], 10), location)
+            self.scan_over_(".")
+            self.scan_over_(Lexer.CHAR_DIGIT_)
+            return (Lexer.FLOAT, float(text[start:self.pos_]), location)
         if cur_char == "-" and next_char in Lexer.CHAR_DIGIT_:
             self.pos_ += 1
             self.scan_over_(Lexer.CHAR_DIGIT_)
-            return (Lexer.NUMBER, int(text[start:self.pos_], 10), location)
+            if self.pos_ >= limit or text[self.pos_] != ".":
+                return (Lexer.NUMBER, int(text[start:self.pos_], 10), location)
+            self.scan_over_(".")
+            self.scan_over_(Lexer.CHAR_DIGIT_)
+            return (Lexer.FLOAT, float(text[start:self.pos_]), location)
         if cur_char in Lexer.CHAR_SYMBOL_:
             self.pos_ += 1
             return (Lexer.SYMBOL, cur_char, location)

Lib/fontTools/feaLib/lexer_test.py

@@ -66,6 +66,10 @@ class LexerTest(unittest.TestCase):
         self.assertEqual(lex("0xCAFED00D"), [(Lexer.NUMBER, 0xCAFED00D)])
         self.assertEqual(lex("0xcafed00d"), [(Lexer.NUMBER, 0xCAFED00D)])
 
+    def test_float(self):
+        self.assertEqual(lex("1.23 -4.5"),
+                         [(Lexer.FLOAT, 1.23), (Lexer.FLOAT, -4.5)])
+
     def test_symbol(self):
         self.assertEqual(lex("a'"), [(Lexer.NAME, "a"), (Lexer.SYMBOL, "'")])
         self.assertEqual(

Lib/fontTools/feaLib/parser.py

@@ -628,6 +628,7 @@ class Parser(object):
         self.expect_symbol_("{")
         handler = {
             "GDEF": self.parse_table_GDEF_,
+            "head": self.parse_table_head_,
         }.get(name)
         if handler:
             handler(table)
@@ -660,6 +661,16 @@ class Parser(object):
                     "or LigatureCaretByPos",
                     self.cur_token_location_)
 
+    def parse_table_head_(self, table):
+        statements = table.statements
+        while self.next_token_ != "}":
+            self.advance_lexer_()
+            if self.is_cur_keyword_("FontRevision"):
+                statements.append(self.parse_FontRevision_())
+            else:
+                raise FeatureLibError("Expected FontRevision",
+                                      self.cur_token_location_)
+
     def parse_device_(self):
         result = None
         self.expect_symbol_("<")
@@ -772,6 +783,15 @@ class Parser(object):
         self.expect_symbol_(";")
         return ast.FeatureReferenceStatement(location, featureName)
 
+    def parse_FontRevision_(self):
+        assert self.cur_token_ == "FontRevision", self.cur_token_
+        location, version = self.cur_token_location_, self.expect_float_()
+        self.expect_symbol_(";")
+        if version <= 0:
+            raise FeatureLibError("Font revision numbers must be positive",
+                                  location)
+        return ast.FontRevisionStatement(location, version)
+
     def parse_block_(self, block, vertical):
         self.expect_symbol_("{")
         for symtab in self.symbol_tables_:
@@ -901,6 +921,13 @@ class Parser(object):
             return self.cur_token_
         raise FeatureLibError("Expected a number", self.cur_token_location_)
 
+    def expect_float_(self):
+        self.advance_lexer_()
+        if self.cur_token_type_ is Lexer.FLOAT:
+            return self.cur_token_
+        raise FeatureLibError("Expected a floating-point number",
+                              self.cur_token_location_)
+
     def advance_lexer_(self):
         self.cur_token_type_, self.cur_token_, self.cur_token_location_ = (
             self.next_token_type_, self.next_token_, self.next_token_location_)

Lib/fontTools/feaLib/parser_test.py

@@ -138,6 +138,17 @@ class ParserTest(unittest.TestCase):
         self.assertIsInstance(ref, ast.FeatureReferenceStatement)
         self.assertEqual(ref.featureName, "salt")
 
+    def test_FontRevision(self):
+        doc = self.parse("table head {FontRevision 2.5;} head;")
+        s = doc.statements[0].statements[0]
+        self.assertIsInstance(s, ast.FontRevisionStatement)
+        self.assertEqual(s.revision, 2.5)
+
+    def test_FontRevision_negative(self):
+        self.assertRaisesRegex(
+            FeatureLibError, "Font revision numbers must be positive",
+            self.parse, "table head {FontRevision -17.2;} head;")
+
     def test_glyphclass(self):
         [gc] = self.parse("@dash = [endash emdash figuredash];").statements
         self.assertEqual(gc.name, "dash")

Lib/fontTools/feaLib/testdata/spec9c1.fea

@@ -0,0 +1,3 @@
+table head {
+    FontRevision 1.1;
+} head;

Lib/fontTools/feaLib/testdata/spec9c1.ttx

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ttFont>
+
+  <head>
+    <!-- Most of this table will be recalculated by the compiler -->
+    <tableVersion value="1.0"/>
+    <fontRevision value="1.1"/>
+    <checkSumAdjustment value="0x0"/>
+    <magicNumber value="0x0"/>
+    <flags value="00000000 00000000"/>
+    <unitsPerEm value="0"/>
+    <created value="Thu Jan  1 00:00:00 1970"/>
+    <modified value="Thu Jan  1 00:00:00 1970"/>
+    <xMin value="0"/>
+    <yMin value="0"/>
+    <xMax value="0"/>
+    <yMax value="0"/>
+    <macStyle value="00000000 00000000"/>
+    <lowestRecPPEM value="0"/>
+    <fontDirectionHint value="0"/>
+    <indexToLocFormat value="0"/>
+    <glyphDataFormat value="0"/>
+  </head>
+
+</ttFont>

Lib/fontTools/feaLib/testdata/spec9c2.fea

@@ -0,0 +1,3 @@
+table head {
+    FontRevision 1.001;
+} head;

Lib/fontTools/feaLib/testdata/spec9c2.ttx

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ttFont>
+
+  <head>
+    <!-- Most of this table will be recalculated by the compiler -->
+    <tableVersion value="1.0"/>
+    <fontRevision value="1.001"/>
+    <checkSumAdjustment value="0x0"/>
+    <magicNumber value="0x0"/>
+    <flags value="00000000 00000000"/>
+    <unitsPerEm value="0"/>
+    <created value="Thu Jan  1 00:00:00 1970"/>
+    <modified value="Thu Jan  1 00:00:00 1970"/>
+    <xMin value="0"/>
+    <yMin value="0"/>
+    <xMax value="0"/>
+    <yMax value="0"/>
+    <macStyle value="00000000 00000000"/>
+    <lowestRecPPEM value="0"/>
+    <fontDirectionHint value="0"/>
+    <indexToLocFormat value="0"/>
+    <glyphDataFormat value="0"/>
+  </head>
+
+</ttFont>

Lib/fontTools/feaLib/testdata/spec9c3.fea

@@ -0,0 +1,3 @@
+table head {
+    FontRevision 1.500;
+} head;

Lib/fontTools/feaLib/testdata/spec9c3.ttx

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ttFont>
+
+  <head>
+    <!-- Most of this table will be recalculated by the compiler -->
+    <tableVersion value="1.0"/>
+    <fontRevision value="1.5"/>
+    <checkSumAdjustment value="0x0"/>
+    <magicNumber value="0x0"/>
+    <flags value="00000000 00000000"/>
+    <unitsPerEm value="0"/>
+    <created value="Thu Jan  1 00:00:00 1970"/>
+    <modified value="Thu Jan  1 00:00:00 1970"/>
+    <xMin value="0"/>
+    <yMin value="0"/>
+    <xMax value="0"/>
+    <yMax value="0"/>
+    <macStyle value="00000000 00000000"/>
+    <lowestRecPPEM value="0"/>
+    <fontDirectionHint value="0"/>
+    <indexToLocFormat value="0"/>
+    <glyphDataFormat value="0"/>
+  </head>
+
+</ttFont>