class Parser(object):
def __init__(self, path):
self.doc_ = ast.FeatureFile()
self.anchors_ = SymbolTable()
self.glyphclasses_ = SymbolTable()
self.lookups_ = SymbolTable()
self.valuerecords_ = SymbolTable()
self.symbol_tables_ = {
self.anchors_, self.valuerecords_
}
self.next_token_type_, self.next_token_ = (None, None)
self.next_token_location_ = None
self.lexer_ = IncludingLexer(path)
self.advance_lexer_()
def parse(self):
statements = self.doc_.statements
while self.next_token_type_ is not None:
self.advance_lexer_()
if self.cur_token_type_ is Lexer.GLYPHCLASS:
statements.append(self.parse_glyphclass_definition_())
elif self.is_cur_keyword_("anchorDef"):
statements.append(self.parse_anchordef_())
elif self.is_cur_keyword_("languagesystem"):
statements.append(self.parse_languagesystem_())
elif self.is_cur_keyword_("lookup"):
statements.append(self.parse_lookup_(vertical=False))
elif self.is_cur_keyword_("markClass"):
statements.append(self.parse_markClass_())
elif self.is_cur_keyword_("feature"):
statements.append(self.parse_feature_block_())
elif self.is_cur_keyword_("table"):
statements.append(self.parse_table_())
elif self.is_cur_keyword_("valueRecordDef"):
statements.append(
self.parse_valuerecord_definition_(vertical=False))
else:
raise FeatureLibError(
"Expected feature, languagesystem, lookup, markClass, "
"table, or glyph class definition",
self.cur_token_location_)
return self.doc_
def parse_anchor_(self):
self.expect_symbol_("<")
self.expect_keyword_("anchor")
location = self.cur_token_location_
if self.next_token_ == "NULL":
self.expect_keyword_("NULL")
self.expect_symbol_(">")
return None
if self.next_token_type_ == Lexer.NAME:
name = self.expect_name_()
anchordef = self.anchors_.resolve(name)
if anchordef is None:
raise FeatureLibError(
'Unknown anchor "%s"' % name,
self.cur_token_location_)
self.expect_symbol_(">")
return ast.Anchor(location, anchordef.x, anchordef.y,
anchordef.contourpoint,
xDeviceTable=None, yDeviceTable=None)
x, y = self.expect_number_(), self.expect_number_()
contourpoint = None
if self.next_token_ == "contourpoint":
self.expect_keyword_("contourpoint")
contourpoint = self.expect_number_()
if self.next_token_ == "<":
xDeviceTable = self.parse_device_()
yDeviceTable = self.parse_device_()
else:
xDeviceTable, yDeviceTable = None, None
self.expect_symbol_(">")
return ast.Anchor(location, x, y, contourpoint,
xDeviceTable, yDeviceTable)
def parse_anchor_marks_(self):
"""Parses a sequence of [<anchor> mark @MARKCLASS]*."""
anchorMarks = [] # [(ast.Anchor, markClassName)*]
while self.next_token_ == "<":
anchor = self.parse_anchor_()
if anchor is None and self.next_token_ != "mark":
continue # <anchor NULL> without mark, eg. in GPOS type 5
self.expect_keyword_("mark")
markClass = self.expect_markClass_reference_()
anchorMarks.append((anchor, markClass))
return anchorMarks
def parse_anchordef_(self):
assert self.is_cur_keyword_("anchorDef")
location = self.cur_token_location_
x, y = self.expect_number_(), self.expect_number_()
contourpoint = None
if self.next_token_ == "contourpoint":
self.expect_keyword_("contourpoint")
contourpoint = self.expect_number_()
name = self.expect_name_()
self.expect_symbol_(";")
anchordef = ast.AnchorDefinition(location, name, x, y, contourpoint)
self.anchors_.define(name, anchordef)
return anchordef
def parse_attach_(self):
assert self.is_cur_keyword_("Attach")
location = self.cur_token_location_
glyphs = self.parse_glyphclass_(accept_glyphname=True)
contourPoints = {self.expect_number_()}
while self.next_token_ != ";":
contourPoints.add(self.expect_number_())
self.expect_symbol_(";")
return ast.AttachStatement(location, glyphs, contourPoints)
def parse_enumerate_(self, vertical):
assert self.cur_token_ in {"enumerate", "enum"}
self.advance_lexer_()
return self.parse_position_(enumerated=True, vertical=vertical)
def parse_GlyphClassDef_(self):
"""Parses 'GlyphClassDef @BASE, @LIGATURES, @MARKS, @COMPONENTS;'"""
assert self.is_cur_keyword_("GlyphClassDef")
location = self.cur_token_location_
if self.next_token_ != ",":
baseGlyphs = self.parse_glyphclass_(accept_glyphname=False)
else:
baseGlyphs = None
self.expect_symbol_(",")
if self.next_token_ != ",":
ligatureGlyphs = self.parse_glyphclass_(accept_glyphname=False)
else:
ligatureGlyphs = None
self.expect_symbol_(",")
if self.next_token_ != ",":
markGlyphs = self.parse_glyphclass_(accept_glyphname=False)
else:
markGlyphs = None
self.expect_symbol_(",")
if self.next_token_ != ";":
componentGlyphs = self.parse_glyphclass_(accept_glyphname=False)
else:
componentGlyphs = None
self.expect_symbol_(";")
return ast.GlyphClassDefStatement(location, baseGlyphs, markGlyphs,
ligatureGlyphs, componentGlyphs)
def parse_glyphclass_definition_(self):
"""Parses glyph class definitions such as '@UPPERCASE = [A-Z];'"""
location, name = self.cur_token_location_, self.cur_token_
self.expect_symbol_("=")
glyphs = self.parse_glyphclass_(accept_glyphname=False).glyphSet()
self.expect_symbol_(";")
glyphclass = ast.GlyphClassDefinition(location, name, glyphs)
self.glyphclasses_.define(name, glyphclass)
return glyphclass
def parse_glyphclass_(self, accept_glyphname):
if (accept_glyphname and
self.next_token_type_ in (Lexer.NAME, Lexer.CID)):
glyph = self.expect_glyph_()
return ast.GlyphName(self.cur_token_location_, glyph)
if self.next_token_type_ is Lexer.GLYPHCLASS:
self.advance_lexer_()
gc = self.glyphclasses_.resolve(self.cur_token_)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % self.cur_token_,
self.cur_token_location_)
if isinstance(gc, ast.MarkClass):
return ast.MarkClassName(self.cur_token_location_, gc)
else:
return ast.GlyphClassName(self.cur_token_location_, gc)
self.expect_symbol_("[")
glyphs = set()
location = self.cur_token_location_
while self.next_token_ != "]":
if self.next_token_type_ is Lexer.NAME:
glyph = self.expect_glyph_()
if self.next_token_ == "-":
range_location = self.cur_token_location_
range_start = glyph
self.expect_symbol_("-")
range_end = self.expect_glyph_()
glyphs.update(self.make_glyph_range_(range_location,
range_start,
range_end))
else:
glyphs.add(glyph)
elif self.next_token_type_ is Lexer.CID:
glyph = self.expect_glyph_()
if self.next_token_ == "-":
range_location = self.cur_token_location_
range_start = self.cur_token_
self.expect_symbol_("-")
range_end = self.expect_cid_()
glyphs.update(self.make_cid_range_(range_location,
range_start, range_end))
else:
glyphs.add("cid%05d" % self.cur_token_)
elif self.next_token_type_ is Lexer.GLYPHCLASS:
self.advance_lexer_()
gc = self.glyphclasses_.resolve(self.cur_token_)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % self.cur_token_,
self.cur_token_location_)
glyphs.update(gc.glyphSet())
else:
raise FeatureLibError(
"Expected glyph name, glyph range, "
"or glyph class reference",
self.next_token_location_)
self.expect_symbol_("]")
return ast.GlyphClass(location, glyphs)
def parse_class_name_(self):
name = self.expect_class_name_()
gc = self.glyphclasses_.resolve(name)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % name,
self.cur_token_location_)
if isinstance(gc, ast.MarkClass):
return ast.MarkClassName(self.cur_token_location_, gc)
else:
return ast.GlyphClassName(self.cur_token_location_, gc)
def parse_glyph_pattern_(self, vertical):
prefix, glyphs, lookups, values, suffix = ([], [], [], [], [])
hasMarks = False
while self.next_token_ not in {"by", "from", ";", ","}:
gc = self.parse_glyphclass_(accept_glyphname=True)
marked = False
if self.next_token_ == "'":
self.expect_symbol_("'")
hasMarks = marked = True
if marked:
glyphs.append(gc)
elif glyphs:
suffix.append(gc)
else:
prefix.append(gc)
if self.is_next_value_():
values.append(self.parse_valuerecord_(vertical))
else:
values.append(None)
lookup = None
if self.next_token_ == "lookup":
self.expect_keyword_("lookup")
if not marked:
raise FeatureLibError(
"Lookups can only follow marked glyphs",
self.cur_token_location_)
lookup_name = self.expect_name_()
lookup = self.lookups_.resolve(lookup_name)
if lookup is None:
raise FeatureLibError(
'Unknown lookup "%s"' % lookup_name,
self.cur_token_location_)
if marked:
lookups.append(lookup)
if not glyphs and not suffix: # eg., "sub f f i by"
assert lookups == []
return ([], prefix, [None] * len(prefix), values, [], hasMarks)
else:
assert not any(values[:len(prefix)]), values
values = values[len(prefix):][:len(glyphs)]
return (prefix, glyphs, lookups, values, suffix, hasMarks)
def parse_chain_context_(self):
location = self.cur_token_location_
prefix, glyphs, lookups, values, suffix, hasMarks = \
self.parse_glyph_pattern_(vertical=False)
chainContext = [(prefix, glyphs, suffix)]
hasLookups = any(lookups)
while self.next_token_ == ",":
self.expect_symbol_(",")
prefix, glyphs, lookups, values, suffix, hasMarks = \
self.parse_glyph_pattern_(vertical=False)
chainContext.append((prefix, glyphs, suffix))
hasLookups = hasLookups or any(lookups)
self.expect_symbol_(";")
return chainContext, hasLookups
def parse_ignore_(self):
assert self.is_cur_keyword_("ignore")
location = self.cur_token_location_
self.advance_lexer_()
if self.cur_token_ in ["substitute", "sub"]:
chainContext, hasLookups = self.parse_chain_context_()
if hasLookups:
raise FeatureLibError(
"No lookups can be specified for \"ignore sub\"",
location)
return ast.IgnoreSubstStatement(location, chainContext)
if self.cur_token_ in ["position", "pos"]:
chainContext, hasLookups = self.parse_chain_context_()
if hasLookups:
raise FeatureLibError(
"No lookups can be specified for \"ignore pos\"",
location)
return ast.IgnorePosStatement(location, chainContext)
raise FeatureLibError(
"Expected \"substitute\" or \"position\"",
self.cur_token_location_)
def parse_language_(self):
assert self.is_cur_keyword_("language")
location = self.cur_token_location_
language = self.expect_language_tag_()
include_default, required = (True, False)
if self.next_token_ in {"exclude_dflt", "include_dflt"}:
include_default = (self.expect_name_() == "include_dflt")
if self.next_token_ == "required":
self.expect_keyword_("required")
required = True
self.expect_symbol_(";")
return ast.LanguageStatement(location, language,
include_default, required)
def parse_ligatureCaretByIndex_(self):
assert self.is_cur_keyword_("LigatureCaretByIndex")
location = self.cur_token_location_
glyphs = self.parse_glyphclass_(accept_glyphname=True)
carets = {self.expect_number_()}
while self.next_token_ != ";":
carets.add(self.expect_number_())
self.expect_symbol_(";")
return ast.LigatureCaretByIndexStatement(location, glyphs, carets)
def parse_ligatureCaretByPos_(self):
assert self.is_cur_keyword_("LigatureCaretByPos")
location = self.cur_token_location_
glyphs = self.parse_glyphclass_(accept_glyphname=True)
carets = {self.expect_number_()}
while self.next_token_ != ";":
carets.add(self.expect_number_())
self.expect_symbol_(";")
return ast.LigatureCaretByPosStatement(location, glyphs, carets)
def parse_lookup_(self, vertical):
assert self.is_cur_keyword_("lookup")
location, name = self.cur_token_location_, self.expect_name_()
if self.next_token_ == ";":
lookup = self.lookups_.resolve(name)
if lookup is None:
raise FeatureLibError("Unknown lookup \"%s\"" % name,
self.cur_token_location_)
self.expect_symbol_(";")
return ast.LookupReferenceStatement(location, lookup)
use_extension = False
if self.next_token_ == "useExtension":
self.expect_keyword_("useExtension")
use_extension = True
block = ast.LookupBlock(location, name, use_extension)
self.parse_block_(block, vertical)
self.lookups_.define(name, block)
return block
def parse_lookupflag_(self):
assert self.is_cur_keyword_("lookupflag")
location = self.cur_token_location_
# format B: "lookupflag 6;"
if self.next_token_type_ == Lexer.NUMBER:
value = self.expect_number_()
self.expect_symbol_(";")
return ast.LookupFlagStatement(location, value, None, None)
# format A: "lookupflag RightToLeft MarkAttachmentType @M;"
value, markAttachment, markFilteringSet = 0, None, None
flags = {
"RightToLeft": 1, "IgnoreBaseGlyphs": 2,
"IgnoreLigatures": 4, "IgnoreMarks": 8
}
seen = set()
while self.next_token_ != ";":
if self.next_token_ in seen:
raise FeatureLibError(
"%s can be specified only once" % self.next_token_,
self.next_token_location_)
seen.add(self.next_token_)
if self.next_token_ == "MarkAttachmentType":
self.expect_keyword_("MarkAttachmentType")
markAttachment = self.parse_class_name_()
elif self.next_token_ == "UseMarkFilteringSet":
self.expect_keyword_("UseMarkFilteringSet")
markFilteringSet = self.parse_class_name_()
elif self.next_token_ in flags:
value = value | flags[self.expect_name_()]
else:
raise FeatureLibError(
'"%s" is not a recognized lookupflag' % self.next_token_,
self.next_token_location_)
self.expect_symbol_(";")
return ast.LookupFlagStatement(location, value,
markAttachment, markFilteringSet)
def parse_markClass_(self):
assert self.is_cur_keyword_("markClass")
location = self.cur_token_location_
glyphs = self.parse_glyphclass_(accept_glyphname=True)
anchor = self.parse_anchor_()
name = self.expect_class_name_()
self.expect_symbol_(";")
markClass = self.doc_.markClasses.get(name)
if markClass is None:
markClass = ast.MarkClass(name)
self.doc_.markClasses[name] = markClass
self.glyphclasses_.define(name, markClass)
mcdef = ast.MarkClassDefinition(location, markClass, anchor, glyphs)
markClass.addDefinition(mcdef)
return mcdef
def parse_position_(self, enumerated, vertical):
assert self.cur_token_ in {"position", "pos"}
if self.next_token_ == "cursive": # GPOS type 3
return self.parse_position_cursive_(enumerated, vertical)
elif self.next_token_ == "base": # GPOS type 4
return self.parse_position_base_(enumerated, vertical)
elif self.next_token_ == "ligature": # GPOS type 5
return self.parse_position_ligature_(enumerated, vertical)
elif self.next_token_ == "mark": # GPOS type 6
return self.parse_position_mark_(enumerated, vertical)
location = self.cur_token_location_
prefix, glyphs, lookups, values, suffix, hasMarks = \
self.parse_glyph_pattern_(vertical)
self.expect_symbol_(";")
if any(lookups):
# GPOS type 8: Chaining contextual positioning; explicit lookups
if any(values):
raise FeatureLibError(
"If \"lookup\" is present, no values must be specified",
location)
return ast.ChainContextPosStatement(
location, prefix, glyphs, suffix, lookups)
# Pair positioning, format A: "pos V 10 A -10;"
# Pair positioning, format B: "pos V A -20;"
if not prefix and not suffix and len(glyphs) == 2 and not hasMarks:
if values[0] is None: # Format B: "pos V A -20;"
values.reverse()
return ast.PairPosStatement(
location, enumerated,
glyphs[0], values[0], glyphs[1], values[1])
if enumerated:
raise FeatureLibError(
'"enumerate" is only allowed with pair positionings', location)
return ast.SinglePosStatement(location, list(zip(glyphs, values)),
prefix, suffix, forceChain=hasMarks)
def parse_position_cursive_(self, enumerated, vertical):
location = self.cur_token_location_
self.expect_keyword_("cursive")
if enumerated:
raise FeatureLibError(
'"enumerate" is not allowed with '
'cursive attachment positioning',
location)
glyphclass = self.parse_glyphclass_(accept_glyphname=True).glyphSet()
entryAnchor = self.parse_anchor_()
exitAnchor = self.parse_anchor_()
self.expect_symbol_(";")
return ast.CursivePosStatement(
location, glyphclass, entryAnchor, exitAnchor)
def parse_position_base_(self, enumerated, vertical):
location = self.cur_token_location_
self.expect_keyword_("base")
if enumerated:
raise FeatureLibError(
'"enumerate" is not allowed with '
'mark-to-base attachment positioning',
location)
base = self.parse_glyphclass_(accept_glyphname=True).glyphSet()
marks = self.parse_anchor_marks_()
self.expect_symbol_(";")
return ast.MarkBasePosStatement(location, base, marks)
def parse_position_ligature_(self, enumerated, vertical):
location = self.cur_token_location_
self.expect_keyword_("ligature")
if enumerated:
raise FeatureLibError(
'"enumerate" is not allowed with '
'mark-to-ligature attachment positioning',
location)
ligatures = self.parse_glyphclass_(accept_glyphname=True).glyphSet()
marks = [self.parse_anchor_marks_()]
while self.next_token_ == "ligComponent":
self.expect_keyword_("ligComponent")
marks.append(self.parse_anchor_marks_())
self.expect_symbol_(";")
return ast.MarkLigPosStatement(location, ligatures, marks)
def parse_position_mark_(self, enumerated, vertical):
location = self.cur_token_location_
self.expect_keyword_("mark")
if enumerated:
raise FeatureLibError(
'"enumerate" is not allowed with '
'mark-to-mark attachment positioning',
location)
baseMarks = self.parse_glyphclass_(accept_glyphname=True).glyphSet()
marks = self.parse_anchor_marks_()
self.expect_symbol_(";")
return ast.MarkMarkPosStatement(location, baseMarks, marks)
def parse_script_(self):
assert self.is_cur_keyword_("script")
location, script = self.cur_token_location_, self.expect_script_tag_()
self.expect_symbol_(";")
return ast.ScriptStatement(location, script)
def parse_substitute_(self):
assert self.cur_token_ in {"substitute", "sub", "reversesub", "rsub"}
location = self.cur_token_location_
reverse = self.cur_token_ in {"reversesub", "rsub"}
old_prefix, old, lookups, values, old_suffix, hasMarks = \
self.parse_glyph_pattern_(vertical=False)
if any(values):
raise FeatureLibError(
"Substitution statements cannot contain values", location)
new = []
if self.next_token_ == "by":
keyword = self.expect_keyword_("by")
while self.next_token_ != ";":
gc = self.parse_glyphclass_(accept_glyphname=True)
new.append(gc)
elif self.next_token_ == "from":
keyword = self.expect_keyword_("from")
new = [self.parse_glyphclass_(accept_glyphname=False)]
else:
keyword = None
self.expect_symbol_(";")
if len(new) is 0 and not any(lookups):
raise FeatureLibError(
'Expected "by", "from" or explicit lookup references',
self.cur_token_location_)
# GSUB lookup type 3: Alternate substitution.
# Format: "substitute a from [a.1 a.2 a.3];"
if keyword == "from":
if reverse:
raise FeatureLibError(
'Reverse chaining substitutions do not support "from"',
location)
if len(old) != 1 or len(old[0].glyphSet()) != 1:
raise FeatureLibError(
'Expected a single glyph before "from"',
location)
if len(new) != 1:
raise FeatureLibError(
'Expected a single glyphclass after "from"',
location)
return ast.AlternateSubstStatement(
location, old_prefix, old[0], old_suffix, new[0])
num_lookups = len([l for l in lookups if l is not None])
# GSUB lookup type 1: Single substitution.
# Format A: "substitute a by a.sc;"
# Format B: "substitute [one.fitted one.oldstyle] by one;"
# Format C: "substitute [a-d] by [A.sc-D.sc];"
if (not reverse and len(old) == 1 and len(new) == 1 and
num_lookups == 0):
glyphs = sorted(list(old[0].glyphSet()))
replacements = sorted(list(new[0].glyphSet()))
if len(replacements) == 1:
replacements = replacements * len(glyphs)
if len(glyphs) != len(replacements):
raise FeatureLibError(
'Expected a glyph class with %d elements after "by", '
'but found a glyph class with %d elements' %
(len(glyphs), len(replacements)), location)
return ast.SingleSubstStatement(location,
dict(zip(glyphs, replacements)),
old_prefix, old_suffix,
forceChain=hasMarks)
# GSUB lookup type 2: Multiple substitution.
# Format: "substitute f_f_i by f f i;"
if (not reverse and
len(old) == 1 and len(old[0].glyphSet()) == 1 and
len(new) > 1 and max([len(n.glyphSet()) for n in new]) == 1 and
num_lookups == 0):
return ast.MultipleSubstStatement(
location, old_prefix, tuple(old[0].glyphSet())[0], old_suffix,
tuple([list(n.glyphSet())[0] for n in new]))
# GSUB lookup type 4: Ligature substitution.
# Format: "substitute f f i by f_f_i;"
if (not reverse and
len(old) > 1 and len(new) == 1 and
len(new[0].glyphSet()) == 1 and
num_lookups == 0):
return ast.LigatureSubstStatement(
location, old_prefix, old, old_suffix,
list(new[0].glyphSet())[0], forceChain=hasMarks)
# GSUB lookup type 8: Reverse chaining substitution.
if reverse:
if len(old) != 1:
raise FeatureLibError(
"In reverse chaining single substitutions, "
"only a single glyph or glyph class can be replaced",
location)
if len(new) != 1:
raise FeatureLibError(
'In reverse chaining single substitutions, '
'the replacement (after "by") must be a single glyph '
'or glyph class', location)
if num_lookups != 0:
raise FeatureLibError(
"Reverse chaining substitutions cannot call named lookups",
location)
glyphs = sorted(list(old[0].glyphSet()))
replacements = sorted(list(new[0].glyphSet()))
if len(replacements) == 1:
replacements = replacements * len(glyphs)
if len(glyphs) != len(replacements):
raise FeatureLibError(
'Expected a glyph class with %d elements after "by", '
'but found a glyph class with %d elements' %
(len(glyphs), len(replacements)), location)
return ast.ReverseChainSingleSubstStatement(
location, old_prefix, old_suffix,
dict(zip(glyphs, replacements)))
# GSUB lookup type 6: Chaining contextual substitution.
assert len(new) == 0, new
rule = ast.ChainContextSubstStatement(
location, old_prefix, old, old_suffix, lookups)
return rule
def parse_subtable_(self):
assert self.is_cur_keyword_("subtable")
location = self.cur_token_location_
self.expect_symbol_(";")
return ast.SubtableStatement(location)
def parse_table_(self):
assert self.is_cur_keyword_("table")
location, name = self.cur_token_location_, self.expect_tag_()
table = ast.TableBlock(location, name)
self.expect_symbol_("{")
handler = {
"GDEF": self.parse_table_GDEF_,
"head": self.parse_table_head_,
}.get(name)
if handler:
handler(table)
else:
raise FeatureLibError('"table %s" is not supported' % name.strip(),
location)
self.expect_symbol_("}")
end_tag = self.expect_tag_()
if end_tag != name:
raise FeatureLibError('Expected "%s"' % name.strip(),
self.cur_token_location_)
self.expect_symbol_(";")
return table
def parse_table_GDEF_(self, table):
statements = table.statements
while self.next_token_ != "}":
self.advance_lexer_()
if self.is_cur_keyword_("Attach"):
statements.append(self.parse_attach_())
elif self.is_cur_keyword_("GlyphClassDef"):
statements.append(self.parse_GlyphClassDef_())
elif self.is_cur_keyword_("LigatureCaretByIndex"):
statements.append(self.parse_ligatureCaretByIndex_())
elif self.is_cur_keyword_("LigatureCaretByPos"):
statements.append(self.parse_ligatureCaretByPos_())
else:
raise FeatureLibError(
"Expected Attach, LigatureCaretByIndex, "
"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_("<")
self.expect_keyword_("device")
if self.next_token_ == "NULL":
self.expect_keyword_("NULL")
else:
result = [(self.expect_number_(), self.expect_number_())]
while self.next_token_ == ",":
self.expect_symbol_(",")
result.append((self.expect_number_(), self.expect_number_()))
result = tuple(result) # make it hashable
self.expect_symbol_(">")
return result
def is_next_value_(self):
return self.next_token_type_ is Lexer.NUMBER or self.next_token_ == "<"
def parse_valuerecord_(self, vertical):
if self.next_token_type_ is Lexer.NUMBER:
number, location = self.expect_number_(), self.cur_token_location_
if vertical:
val = ast.ValueRecord(location, 0, 0, 0, number,
None, None, None, None)
else:
val = ast.ValueRecord(location, 0, 0, number, 0,
None, None, None, None)
return val
self.expect_symbol_("<")
location = self.cur_token_location_
if self.next_token_type_ is Lexer.NAME:
name = self.expect_name_()
if name == "NULL":
self.expect_symbol_(">")
return None
vrd = self.valuerecords_.resolve(name)
if vrd is None:
raise FeatureLibError("Unknown valueRecordDef \"%s\"" % name,
self.cur_token_location_)
value = vrd.value
xPlacement, yPlacement = (value.xPlacement, value.yPlacement)
xAdvance, yAdvance = (value.xAdvance, value.yAdvance)
else:
xPlacement, yPlacement, xAdvance, yAdvance = (
self.expect_number_(), self.expect_number_(),
self.expect_number_(), self.expect_number_())
if self.next_token_ == "<":
xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice = (
self.parse_device_(), self.parse_device_(),
self.parse_device_(), self.parse_device_())
allDeltas = sorted([
delta
for size, delta
in (xPlaDevice if xPlaDevice else ()) +
(yPlaDevice if yPlaDevice else ()) +
(xAdvDevice if xAdvDevice else ()) +
(yAdvDevice if yAdvDevice else ())])
if allDeltas[0] < -128 or allDeltas[-1] > 127:
raise FeatureLibError(
"Device value out of valid range (-128..127)",
self.cur_token_location_)
else:
xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice = (
None, None, None, None)
self.expect_symbol_(">")
return ast.ValueRecord(
location, xPlacement, yPlacement, xAdvance, yAdvance,
xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice)
def parse_valuerecord_definition_(self, vertical):
assert self.is_cur_keyword_("valueRecordDef")
location = self.cur_token_location_
value = self.parse_valuerecord_(vertical)
name = self.expect_name_()
self.expect_symbol_(";")
vrd = ast.ValueRecordDefinition(location, name, value)
self.valuerecords_.define(name, vrd)
return vrd
def parse_languagesystem_(self):
assert self.cur_token_ == "languagesystem"
location = self.cur_token_location_
script = self.expect_script_tag_()
language = self.expect_language_tag_()
self.expect_symbol_(";")
if script == "DFLT" and language != "dflt":
raise FeatureLibError(
'For script "DFLT", the language must be "dflt"',
self.cur_token_location_)
return ast.LanguageSystemStatement(location, script, language)
def parse_feature_block_(self):
assert self.cur_token_ == "feature"
location = self.cur_token_location_
tag = self.expect_tag_()
vertical = (tag in {"vkrn", "vpal", "vhal", "valt"})
use_extension = False
if self.next_token_ == "useExtension":
self.expect_keyword_("useExtension")
use_extension = True
block = ast.FeatureBlock(location, tag, use_extension)
self.parse_block_(block, vertical)
return block
def parse_feature_reference_(self):
assert self.cur_token_ == "feature", self.cur_token_
location = self.cur_token_location_
featureName = self.expect_tag_()
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_:
symtab.enter_scope()
statements = block.statements
while self.next_token_ != "}":
self.advance_lexer_()
if self.cur_token_type_ is Lexer.GLYPHCLASS:
statements.append(self.parse_glyphclass_definition_())
elif self.is_cur_keyword_("anchorDef"):
statements.append(self.parse_anchordef_())
elif self.is_cur_keyword_({"enum", "enumerate"}):
statements.append(self.parse_enumerate_(vertical=vertical))
elif self.is_cur_keyword_("feature"):
statements.append(self.parse_feature_reference_())
elif self.is_cur_keyword_("ignore"):
statements.append(self.parse_ignore_())
elif self.is_cur_keyword_("language"):
statements.append(self.parse_language_())
elif self.is_cur_keyword_("lookup"):
statements.append(self.parse_lookup_(vertical))
elif self.is_cur_keyword_("lookupflag"):
statements.append(self.parse_lookupflag_())
elif self.is_cur_keyword_("markClass"):
statements.append(self.parse_markClass_())
elif self.is_cur_keyword_({"pos", "position"}):
statements.append(
self.parse_position_(enumerated=False, vertical=vertical))
elif self.is_cur_keyword_("script"):
statements.append(self.parse_script_())
elif (self.is_cur_keyword_({"sub", "substitute",
"rsub", "reversesub"})):
statements.append(self.parse_substitute_())
elif self.is_cur_keyword_("subtable"):
statements.append(self.parse_subtable_())
elif self.is_cur_keyword_("valueRecordDef"):
statements.append(self.parse_valuerecord_definition_(vertical))
elif self.cur_token_ == ";":
continue
else:
raise FeatureLibError(
"Expected glyph class definition or statement",
self.cur_token_location_)
self.expect_symbol_("}")
for symtab in self.symbol_tables_:
symtab.exit_scope()
name = self.expect_name_()
if name != block.name.strip():
raise FeatureLibError("Expected \"%s\"" % block.name.strip(),
self.cur_token_location_)
self.expect_symbol_(";")
def is_cur_keyword_(self, k):
if self.cur_token_type_ is Lexer.NAME:
if isinstance(k, type("")): # basestring is gone in Python3
return self.cur_token_ == k
else:
return self.cur_token_ in k
return False
def expect_class_name_(self):
self.advance_lexer_()
if self.cur_token_type_ is not Lexer.GLYPHCLASS:
raise FeatureLibError("Expected @NAME", self.cur_token_location_)
return self.cur_token_
def expect_cid_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.CID:
return self.cur_token_
raise FeatureLibError("Expected a CID", self.cur_token_location_)
def expect_glyph_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME:
if len(self.cur_token_) > 63:
raise FeatureLibError(
"Glyph names must not be longer than 63 characters",
self.cur_token_location_)
return self.cur_token_
elif self.cur_token_type_ is Lexer.CID:
return "cid%05d" % self.cur_token_
raise FeatureLibError("Expected a glyph name or CID",
self.cur_token_location_)
def expect_markClass_reference_(self):
name = self.expect_class_name_()
mc = self.glyphclasses_.resolve(name)
if mc is None:
raise FeatureLibError("Unknown markClass @%s" % name,
self.cur_token_location_)
if not isinstance(mc, ast.MarkClass):
raise FeatureLibError("@%s is not a markClass" % name,
self.cur_token_location_)
return mc
def expect_tag_(self):
self.advance_lexer_()
if self.cur_token_type_ is not Lexer.NAME:
raise FeatureLibError("Expected a tag", self.cur_token_location_)
if len(self.cur_token_) > 4:
raise FeatureLibError("Tags can not be longer than 4 characters",
self.cur_token_location_)
return (self.cur_token_ + " ")[:4]
def expect_script_tag_(self):
tag = self.expect_tag_()
if tag == "dflt":
raise FeatureLibError(
'"dflt" is not a valid script tag; use "DFLT" instead',
self.cur_token_location_)
return tag
def expect_language_tag_(self):
tag = self.expect_tag_()
if tag == "DFLT":
raise FeatureLibError(
'"DFLT" is not a valid language tag; use "dflt" instead',
self.cur_token_location_)
return tag
def expect_symbol_(self, symbol):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.SYMBOL and self.cur_token_ == symbol:
return symbol
raise FeatureLibError("Expected '%s'" % symbol,
self.cur_token_location_)
def expect_keyword_(self, keyword):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME and self.cur_token_ == keyword:
return self.cur_token_
raise FeatureLibError("Expected \"%s\"" % keyword,
self.cur_token_location_)
def expect_name_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME:
return self.cur_token_
raise FeatureLibError("Expected a name", self.cur_token_location_)
def expect_number_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NUMBER:
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_)
try:
(self.next_token_type_, self.next_token_,
self.next_token_location_) = self.lexer_.next()
except StopIteration:
self.next_token_type_, self.next_token_ = (None, None)
@staticmethod
def reverse_string_(s):
"""'abc' --> 'cba'"""
return ''.join(reversed(list(s)))
def make_cid_range_(self, location, start, limit):
"""(location, 999, 1001) --> {"cid00999", "cid01000", "cid01001"}"""
result = set()
if start > limit:
raise FeatureLibError(
"Bad range: start should be less than limit", location)
for cid in range(start, limit + 1):
result.add("cid%05d" % cid)
return result
def make_glyph_range_(self, location, start, limit):
"""(location, "a.sc", "d.sc") --> {"a.sc", "b.sc", "c.sc", "d.sc"}"""
result = set()
if len(start) != len(limit):
raise FeatureLibError(
"Bad range: \"%s\" and \"%s\" should have the same length" %
(start, limit), location)
rev = self.reverse_string_
prefix = os.path.commonprefix([start, limit])
suffix = rev(os.path.commonprefix([rev(start), rev(limit)]))
if len(suffix) > 0:
start_range = start[len(prefix):-len(suffix)]
limit_range = limit[len(prefix):-len(suffix)]
else:
start_range = start[len(prefix):]
limit_range = limit[len(prefix):]
if start_range >= limit_range:
raise FeatureLibError(
"Start of range must be smaller than its end",
location)
uppercase = re.compile(r'^[A-Z]$')
if uppercase.match(start_range) and uppercase.match(limit_range):
for c in range(ord(start_range), ord(limit_range) + 1):
result.add("%s%c%s" % (prefix, c, suffix))
return result
lowercase = re.compile(r'^[a-z]$')
if lowercase.match(start_range) and lowercase.match(limit_range):
for c in range(ord(start_range), ord(limit_range) + 1):
result.add("%s%c%s" % (prefix, c, suffix))
return result
digits = re.compile(r'^[0-9]{1,3}$')
if digits.match(start_range) and digits.match(limit_range):
for i in range(int(start_range, 10), int(limit_range, 10) + 1):
number = ("000" + str(i))[-len(start_range):]
result.add("%s%s%s" % (prefix, number, suffix))
return result
raise FeatureLibError("Bad range: \"%s-%s\"" % (start, limit),
location)
class Parser(object):
def __init__(self, path):
self.doc_ = ast.FeatureFile()
self.anchors_ = SymbolTable()
self.glyphclasses_ = SymbolTable()
self.lookups_ = SymbolTable()
self.valuerecords_ = SymbolTable()
self.symbol_tables_ = {
self.anchors_, self.glyphclasses_, self.lookups_,
self.valuerecords_
}
self.next_token_type_, self.next_token_ = (None, None)
self.next_token_location_ = None
self.lexer_ = IncludingLexer(path)
self.advance_lexer_()
def parse(self):
statements = self.doc_.statements
while self.next_token_type_ is not None:
self.advance_lexer_()
if self.cur_token_type_ is Lexer.GLYPHCLASS:
statements.append(self.parse_glyphclass_definition_())
elif self.is_cur_keyword_("anchorDef"):
statements.append(self.parse_anchordef_())
elif self.is_cur_keyword_("languagesystem"):
statements.append(self.parse_languagesystem_())
elif self.is_cur_keyword_("lookup"):
statements.append(self.parse_lookup_(vertical=False))
elif self.is_cur_keyword_("feature"):
statements.append(self.parse_feature_block_())
elif self.is_cur_keyword_("valueRecordDef"):
statements.append(
self.parse_valuerecord_definition_(vertical=False))
else:
raise FeatureLibError(
"Expected feature, languagesystem, "
"lookup, or glyph class definition",
self.cur_token_location_)
return self.doc_
def parse_anchordef_(self):
assert self.is_cur_keyword_("anchorDef")
location = self.cur_token_location_
x, y = self.expect_number_(), self.expect_number_()
contourpoint = None
if self.next_token_ == "contourpoint":
self.expect_keyword_("contourpoint")
contourpoint = self.expect_number_()
name = self.expect_name_()
self.expect_symbol_(";")
anchordef = ast.AnchorDefinition(location, name, x, y, contourpoint)
self.anchors_.define(name, anchordef)
return anchordef
def parse_glyphclass_definition_(self):
location, name = self.cur_token_location_, self.cur_token_
self.expect_symbol_("=")
glyphs = self.parse_glyphclass_(accept_glyphname=False)
self.expect_symbol_(";")
if self.glyphclasses_.resolve(name) is not None:
raise FeatureLibError("Glyph class @%s already defined" % name,
location)
glyphclass = ast.GlyphClassDefinition(location, name, glyphs)
self.glyphclasses_.define(name, glyphclass)
return glyphclass
def parse_glyphclass_(self, accept_glyphname):
result = set()
if accept_glyphname and self.next_token_type_ is Lexer.NAME:
result.add(self.expect_name_())
return result
if self.next_token_type_ is Lexer.GLYPHCLASS:
self.advance_lexer_()
gc = self.glyphclasses_.resolve(self.cur_token_)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % self.cur_token_,
self.cur_token_location_)
result.update(gc.glyphs)
return result
self.expect_symbol_("[")
while self.next_token_ != "]":
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME:
if self.next_token_ == "-":
range_location_ = self.cur_token_location_
range_start = self.cur_token_
self.expect_symbol_("-")
range_end = self.expect_name_()
result.update(
self.make_glyph_range_(range_location_, range_start,
range_end))
else:
result.add(self.cur_token_)
elif self.cur_token_type_ is Lexer.GLYPHCLASS:
gc = self.glyphclasses_.resolve(self.cur_token_)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % self.cur_token_,
self.cur_token_location_)
result.update(gc.glyphs)
else:
raise FeatureLibError(
"Expected glyph name, glyph range, "
"or glyph class reference", self.cur_token_location_)
self.expect_symbol_("]")
return result
def parse_glyph_pattern_(self):
prefix, glyphs, lookups, suffix = ([], [], [], [])
while self.next_token_ not in {"by", "from", ";"}:
gc = self.parse_glyphclass_(accept_glyphname=True)
marked = False
if self.next_token_ == "'":
self.expect_symbol_("'")
marked = True
if marked:
glyphs.append(gc)
elif glyphs:
suffix.append(gc)
else:
prefix.append(gc)
lookup = None
if self.next_token_ == "lookup":
self.expect_keyword_("lookup")
if not marked:
raise FeatureLibError(
"Lookups can only follow marked glyphs",
self.cur_token_location_)
lookup_name = self.expect_name_()
lookup = self.lookups_.resolve(lookup_name)
if lookup is None:
raise FeatureLibError('Unknown lookup "%s"' % lookup_name,
self.cur_token_location_)
if marked:
lookups.append(lookup)
if not glyphs and not suffix: # eg., "sub f f i by"
assert lookups == []
return ([], prefix, [None] * len(prefix), [])
else:
return (prefix, glyphs, lookups, suffix)
def parse_ignore_(self):
assert self.is_cur_keyword_("ignore")
location = self.cur_token_location_
self.advance_lexer_()
if self.cur_token_ in ["substitute", "sub"]:
prefix, glyphs, lookups, suffix = self.parse_glyph_pattern_()
self.expect_symbol_(";")
return ast.IgnoreSubstitutionRule(location, prefix, glyphs, suffix)
raise FeatureLibError("Expected \"substitute\"",
self.next_token_location_)
def parse_language_(self):
assert self.is_cur_keyword_("language")
location = self.cur_token_location_
language = self.expect_language_tag_()
include_default, required = (True, False)
if self.next_token_ in {"exclude_dflt", "include_dflt"}:
include_default = (self.expect_name_() == "include_dflt")
if self.next_token_ == "required":
self.expect_keyword_("required")
required = True
self.expect_symbol_(";")
return ast.LanguageStatement(location, language, include_default,
required)
def parse_lookup_(self, vertical):
assert self.is_cur_keyword_("lookup")
location, name = self.cur_token_location_, self.expect_name_()
if self.next_token_ == ";":
lookup = self.lookups_.resolve(name)
if lookup is None:
raise FeatureLibError("Unknown lookup \"%s\"" % name,
self.cur_token_location_)
self.expect_symbol_(";")
return ast.LookupReferenceStatement(location, lookup)
use_extension = False
if self.next_token_ == "useExtension":
self.expect_keyword_("useExtension")
use_extension = True
block = ast.LookupBlock(location, name, use_extension)
self.parse_block_(block, vertical)
self.lookups_.define(name, block)
return block
def parse_script_(self):
assert self.is_cur_keyword_("script")
location, script = self.cur_token_location_, self.expect_script_tag_()
self.expect_symbol_(";")
return ast.ScriptStatement(location, script)
def parse_substitute_(self):
assert self.cur_token_ in {"substitute", "sub"}
location = self.cur_token_location_
old_prefix, old, lookups, old_suffix = self.parse_glyph_pattern_()
new = []
if self.next_token_ == "by":
keyword = self.expect_keyword_("by")
while self.next_token_ != ";":
new.append(self.parse_glyphclass_(accept_glyphname=True))
elif self.next_token_ == "from":
keyword = self.expect_keyword_("from")
new = [self.parse_glyphclass_(accept_glyphname=False)]
else:
keyword = None
self.expect_symbol_(";")
if len(new) is 0 and not any(lookups):
raise FeatureLibError(
'Expected "by", "from" or explicit lookup references',
self.cur_token_location_)
# GSUB lookup type 3: Alternate substitution.
# Format: "substitute a from [a.1 a.2 a.3];"
if keyword == "from":
if len(old) != 1 or len(old[0]) != 1:
raise FeatureLibError('Expected a single glyph before "from"',
location)
if len(new) != 1:
raise FeatureLibError(
'Expected a single glyphclass after "from"', location)
return ast.AlternateSubstitution(location, list(old[0])[0], new[0])
num_lookups = len([l for l in lookups if l is not None])
# GSUB lookup type 1: Single substitution.
# Format A: "substitute a by a.sc;"
# Format B: "substitute [one.fitted one.oldstyle] by one;"
# Format C: "substitute [a-d] by [A.sc-D.sc];"
if (len(old_prefix) == 0 and len(old_suffix) == 0 and len(old) == 1
and len(new) == 1 and num_lookups == 0):
glyphs, replacements = sorted(list(old[0])), sorted(list(new[0]))
if len(replacements) == 1:
replacements = replacements * len(glyphs)
if len(glyphs) != len(replacements):
raise FeatureLibError(
'Expected a glyph class with %d elements after "by", '
'but found a glyph class with %d elements' %
(len(glyphs), len(replacements)), location)
return ast.SingleSubstitution(location,
dict(zip(glyphs, replacements)))
# GSUB lookup type 2: Multiple substitution.
# Format: "substitute f_f_i by f f i;"
if (len(old_prefix) == 0 and len(old_suffix) == 0 and len(old) == 1
and len(old[0]) == 1 and len(new) > 1
and max([len(n) for n in new]) == 1 and num_lookups == 0):
return ast.MultipleSubstitution(location,
tuple(old[0])[0],
tuple([list(n)[0] for n in new]))
# GSUB lookup type 4: Ligature substitution.
# Format: "substitute f f i by f_f_i;"
if (len(old_prefix) == 0 and len(old_suffix) == 0 and len(old) > 1
and len(new) == 1 and len(new[0]) == 1 and num_lookups == 0):
return ast.LigatureSubstitution(location, old, list(new[0])[0])
rule = ast.SubstitutionRule(location, old, new)
rule.old_prefix, rule.old_suffix = old_prefix, old_suffix
rule.lookups = lookups
return rule
def parse_subtable_(self):
assert self.is_cur_keyword_("subtable")
location = self.cur_token_location_
self.expect_symbol_(";")
return ast.SubtableStatement(location)
def parse_valuerecord_(self, vertical):
if self.next_token_type_ is Lexer.NUMBER:
number, location = self.expect_number_(), self.cur_token_location_
if vertical:
val = ast.ValueRecord(location, 0, 0, 0, number)
else:
val = ast.ValueRecord(location, 0, 0, number, 0)
return val
self.expect_symbol_("<")
location = self.cur_token_location_
if self.next_token_type_ is Lexer.NAME:
name = self.expect_name_()
vrd = self.valuerecords_.resolve(name)
if vrd is None:
raise FeatureLibError("Unknown valueRecordDef \"%s\"" % name,
self.cur_token_location_)
value = vrd.value
xPlacement, yPlacement = (value.xPlacement, value.yPlacement)
xAdvance, yAdvance = (value.xAdvance, value.yAdvance)
else:
xPlacement, yPlacement, xAdvance, yAdvance = (
self.expect_number_(), self.expect_number_(),
self.expect_number_(), self.expect_number_())
self.expect_symbol_(">")
return ast.ValueRecord(location, xPlacement, yPlacement, xAdvance,
yAdvance)
def parse_valuerecord_definition_(self, vertical):
assert self.is_cur_keyword_("valueRecordDef")
location = self.cur_token_location_
value = self.parse_valuerecord_(vertical)
name = self.expect_name_()
self.expect_symbol_(";")
vrd = ast.ValueRecordDefinition(location, name, value)
self.valuerecords_.define(name, vrd)
return vrd
def parse_languagesystem_(self):
assert self.cur_token_ == "languagesystem"
location = self.cur_token_location_
script = self.expect_script_tag_()
language = self.expect_language_tag_()
self.expect_symbol_(";")
if script == "DFLT" and language != "dflt":
raise FeatureLibError(
'For script "DFLT", the language must be "dflt"',
self.cur_token_location_)
return ast.LanguageSystemStatement(location, script, language)
def parse_feature_block_(self):
assert self.cur_token_ == "feature"
location = self.cur_token_location_
tag = self.expect_tag_()
vertical = (tag == "vkrn")
use_extension = False
if self.next_token_ == "useExtension":
self.expect_keyword_("useExtension")
use_extension = True
block = ast.FeatureBlock(location, tag, use_extension)
self.parse_block_(block, vertical)
return block
def parse_block_(self, block, vertical):
self.expect_symbol_("{")
for symtab in self.symbol_tables_:
symtab.enter_scope()
statements = block.statements
while self.next_token_ != "}":
self.advance_lexer_()
if self.cur_token_type_ is Lexer.GLYPHCLASS:
statements.append(self.parse_glyphclass_definition_())
elif self.is_cur_keyword_("anchorDef"):
statements.append(self.parse_anchordef_())
elif self.is_cur_keyword_("ignore"):
statements.append(self.parse_ignore_())
elif self.is_cur_keyword_("language"):
statements.append(self.parse_language_())
elif self.is_cur_keyword_("lookup"):
statements.append(self.parse_lookup_(vertical))
elif self.is_cur_keyword_("script"):
statements.append(self.parse_script_())
elif (self.is_cur_keyword_("substitute")
or self.is_cur_keyword_("sub")):
statements.append(self.parse_substitute_())
elif self.is_cur_keyword_("subtable"):
statements.append(self.parse_subtable_())
elif self.is_cur_keyword_("valueRecordDef"):
statements.append(self.parse_valuerecord_definition_(vertical))
else:
raise FeatureLibError(
"Expected glyph class definition or statement",
self.cur_token_location_)
self.expect_symbol_("}")
for symtab in self.symbol_tables_:
symtab.exit_scope()
name = self.expect_name_()
if name != block.name.strip():
raise FeatureLibError("Expected \"%s\"" % block.name.strip(),
self.cur_token_location_)
self.expect_symbol_(";")
def is_cur_keyword_(self, k):
return (self.cur_token_type_ is Lexer.NAME) and (self.cur_token_ == k)
def expect_tag_(self):
self.advance_lexer_()
if self.cur_token_type_ is not Lexer.NAME:
raise FeatureLibError("Expected a tag", self.cur_token_location_)
if len(self.cur_token_) > 4:
raise FeatureLibError("Tags can not be longer than 4 characters",
self.cur_token_location_)
return (self.cur_token_ + " ")[:4]
def expect_script_tag_(self):
tag = self.expect_tag_()
if tag == "dflt":
raise FeatureLibError(
'"dflt" is not a valid script tag; use "DFLT" instead',
self.cur_token_location_)
return tag
def expect_language_tag_(self):
tag = self.expect_tag_()
if tag == "DFLT":
raise FeatureLibError(
'"DFLT" is not a valid language tag; use "dflt" instead',
self.cur_token_location_)
return tag
def expect_symbol_(self, symbol):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.SYMBOL and self.cur_token_ == symbol:
return symbol
raise FeatureLibError("Expected '%s'" % symbol,
self.cur_token_location_)
def expect_keyword_(self, keyword):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME and self.cur_token_ == keyword:
return self.cur_token_
raise FeatureLibError("Expected \"%s\"" % keyword,
self.cur_token_location_)
def expect_name_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME:
return self.cur_token_
raise FeatureLibError("Expected a name", self.cur_token_location_)
def expect_number_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NUMBER:
return self.cur_token_
raise FeatureLibError("Expected a 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_)
try:
(self.next_token_type_, self.next_token_,
self.next_token_location_) = self.lexer_.next()
except StopIteration:
self.next_token_type_, self.next_token_ = (None, None)
@staticmethod
def reverse_string_(s):
"""'abc' --> 'cba'"""
return ''.join(reversed(list(s)))
def make_glyph_range_(self, location, start, limit):
"""("a.sc", "d.sc") --> {"a.sc", "b.sc", "c.sc", "d.sc"}"""
result = set()
if len(start) != len(limit):
raise FeatureLibError(
"Bad range: \"%s\" and \"%s\" should have the same length" %
(start, limit), location)
rev = self.reverse_string_
prefix = os.path.commonprefix([start, limit])
suffix = rev(os.path.commonprefix([rev(start), rev(limit)]))
if len(suffix) > 0:
start_range = start[len(prefix):-len(suffix)]
limit_range = limit[len(prefix):-len(suffix)]
else:
start_range = start[len(prefix):]
limit_range = limit[len(prefix):]
if start_range >= limit_range:
raise FeatureLibError(
"Start of range must be smaller than its end", location)
uppercase = re.compile(r'^[A-Z]$')
if uppercase.match(start_range) and uppercase.match(limit_range):
for c in range(ord(start_range), ord(limit_range) + 1):
result.add("%s%c%s" % (prefix, c, suffix))
return result
lowercase = re.compile(r'^[a-z]$')
if lowercase.match(start_range) and lowercase.match(limit_range):
for c in range(ord(start_range), ord(limit_range) + 1):
result.add("%s%c%s" % (prefix, c, suffix))
return result
digits = re.compile(r'^[0-9]{1,3}$')
if digits.match(start_range) and digits.match(limit_range):
for i in range(int(start_range, 10), int(limit_range, 10) + 1):
number = ("000" + str(i))[-len(start_range):]
result.add("%s%s%s" % (prefix, number, suffix))
return result
raise FeatureLibError("Bad range: \"%s-%s\"" % (start, limit),
location)
class Parser(object):
def __init__(self, path):
self.doc_ = ast.FeatureFile()
self.anchors_ = SymbolTable()
self.glyphclasses_ = SymbolTable()
self.lookups_ = SymbolTable()
self.valuerecords_ = SymbolTable()
self.symbol_tables_ = {
self.anchors_, self.glyphclasses_,
self.lookups_, self.valuerecords_
}
self.next_token_type_, self.next_token_ = (None, None)
self.next_token_location_ = None
self.lexer_ = IncludingLexer(path)
self.advance_lexer_()
def parse(self):
statements = self.doc_.statements
while self.next_token_type_ is not None:
self.advance_lexer_()
if self.cur_token_type_ is Lexer.GLYPHCLASS:
statements.append(self.parse_glyphclass_definition_())
elif self.is_cur_keyword_("anchorDef"):
statements.append(self.parse_anchordef_())
elif self.is_cur_keyword_("languagesystem"):
statements.append(self.parse_languagesystem_())
elif self.is_cur_keyword_("lookup"):
statements.append(self.parse_lookup_(vertical=False))
elif self.is_cur_keyword_("markClass"):
self.parse_markClass_()
elif self.is_cur_keyword_("feature"):
statements.append(self.parse_feature_block_())
elif self.is_cur_keyword_("valueRecordDef"):
statements.append(
self.parse_valuerecord_definition_(vertical=False))
else:
raise FeatureLibError(
"Expected feature, languagesystem, lookup, markClass, "
"or glyph class definition",
self.cur_token_location_)
return self.doc_
def parse_anchor_(self):
self.expect_symbol_("<")
self.expect_keyword_("anchor")
location = self.cur_token_location_
if self.next_token_ == "NULL":
self.expect_keyword_("NULL")
self.expect_symbol_(">")
return None
if self.next_token_type_ == Lexer.NAME:
name = self.expect_name_()
anchordef = self.anchors_.resolve(name)
if anchordef is None:
raise FeatureLibError(
'Unknown anchor "%s"' % name,
self.cur_token_location_)
self.expect_symbol_(">")
return ast.Anchor(location, anchordef.x, anchordef.y,
anchordef.contourpoint,
xDeviceTable=None, yDeviceTable=None)
x, y = self.expect_number_(), self.expect_number_()
contourpoint = None
if self.next_token_ == "contourpoint":
self.expect_keyword_("contourpoint")
contourpoint = self.expect_number_()
if self.next_token_ == "<":
xDeviceTable = self.parse_device_()
yDeviceTable = self.parse_device_()
else:
xDeviceTable, yDeviceTable = None, None
self.expect_symbol_(">")
return ast.Anchor(location, x, y, contourpoint,
xDeviceTable, yDeviceTable)
def parse_anchordef_(self):
assert self.is_cur_keyword_("anchorDef")
location = self.cur_token_location_
x, y = self.expect_number_(), self.expect_number_()
contourpoint = None
if self.next_token_ == "contourpoint":
self.expect_keyword_("contourpoint")
contourpoint = self.expect_number_()
name = self.expect_name_()
self.expect_symbol_(";")
anchordef = ast.AnchorDefinition(location, name, x, y, contourpoint)
self.anchors_.define(name, anchordef)
return anchordef
def parse_enumerate_(self, vertical):
assert self.cur_token_ in {"enumerate", "enum"}
self.advance_lexer_()
return self.parse_position_(enumerated=True, vertical=vertical)
def parse_glyphclass_definition_(self):
location, name = self.cur_token_location_, self.cur_token_
self.expect_symbol_("=")
glyphs = self.parse_glyphclass_(accept_glyphname=False)
self.expect_symbol_(";")
if self.glyphclasses_.resolve(name) is not None:
raise FeatureLibError("Glyph class @%s already defined" % name,
location)
glyphclass = ast.GlyphClassDefinition(location, name, glyphs)
self.glyphclasses_.define(name, glyphclass)
return glyphclass
def parse_glyphclass_(self, accept_glyphname):
result = set()
if accept_glyphname and self.next_token_type_ is Lexer.NAME:
result.add(self.expect_name_())
return result
if self.next_token_type_ is Lexer.GLYPHCLASS:
self.advance_lexer_()
gc = self.glyphclasses_.resolve(self.cur_token_)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % self.cur_token_,
self.cur_token_location_)
result.update(gc.glyphs)
return result
self.expect_symbol_("[")
while self.next_token_ != "]":
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME:
if self.next_token_ == "-":
range_location_ = self.cur_token_location_
range_start = self.cur_token_
self.expect_symbol_("-")
range_end = self.expect_name_()
result.update(self.make_glyph_range_(range_location_,
range_start,
range_end))
else:
result.add(self.cur_token_)
elif self.cur_token_type_ is Lexer.GLYPHCLASS:
gc = self.glyphclasses_.resolve(self.cur_token_)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % self.cur_token_,
self.cur_token_location_)
result.update(gc.glyphs)
else:
raise FeatureLibError(
"Expected glyph name, glyph range, "
"or glyph class reference",
self.cur_token_location_)
self.expect_symbol_("]")
return result
def parse_glyph_pattern_(self):
prefix, glyphs, lookups, suffix = ([], [], [], [])
while self.next_token_ not in {"by", "from", ";"}:
gc = self.parse_glyphclass_(accept_glyphname=True)
marked = False
if self.next_token_ == "'":
self.expect_symbol_("'")
marked = True
if marked:
glyphs.append(gc)
elif glyphs:
suffix.append(gc)
else:
prefix.append(gc)
lookup = None
if self.next_token_ == "lookup":
self.expect_keyword_("lookup")
if not marked:
raise FeatureLibError(
"Lookups can only follow marked glyphs",
self.cur_token_location_)
lookup_name = self.expect_name_()
lookup = self.lookups_.resolve(lookup_name)
if lookup is None:
raise FeatureLibError(
'Unknown lookup "%s"' % lookup_name,
self.cur_token_location_)
if marked:
lookups.append(lookup)
if not glyphs and not suffix: # eg., "sub f f i by"
assert lookups == []
return ([], prefix, [None] * len(prefix), [])
else:
return (prefix, glyphs, lookups, suffix)
def parse_ignore_(self):
assert self.is_cur_keyword_("ignore")
location = self.cur_token_location_
self.advance_lexer_()
if self.cur_token_ in ["substitute", "sub"]:
prefix, glyphs, lookups, suffix = self.parse_glyph_pattern_()
self.expect_symbol_(";")
return ast.IgnoreSubstitutionRule(location, prefix, glyphs, suffix)
raise FeatureLibError(
"Expected \"substitute\"", self.next_token_location_)
def parse_language_(self):
assert self.is_cur_keyword_("language")
location = self.cur_token_location_
language = self.expect_language_tag_()
include_default, required = (True, False)
if self.next_token_ in {"exclude_dflt", "include_dflt"}:
include_default = (self.expect_name_() == "include_dflt")
if self.next_token_ == "required":
self.expect_keyword_("required")
required = True
self.expect_symbol_(";")
return ast.LanguageStatement(location, language,
include_default, required)
def parse_lookup_(self, vertical):
assert self.is_cur_keyword_("lookup")
location, name = self.cur_token_location_, self.expect_name_()
if self.next_token_ == ";":
lookup = self.lookups_.resolve(name)
if lookup is None:
raise FeatureLibError("Unknown lookup \"%s\"" % name,
self.cur_token_location_)
self.expect_symbol_(";")
return ast.LookupReferenceStatement(location, lookup)
use_extension = False
if self.next_token_ == "useExtension":
self.expect_keyword_("useExtension")
use_extension = True
block = ast.LookupBlock(location, name, use_extension)
self.parse_block_(block, vertical)
self.lookups_.define(name, block)
return block
def parse_markClass_(self):
assert self.is_cur_keyword_("markClass")
location = self.cur_token_location_
glyphs = self.parse_glyphclass_(accept_glyphname=True)
anchor = self.parse_anchor_()
name = self.expect_class_name_()
self.expect_symbol_(";")
markClass = self.doc_.markClasses.get(name)
if markClass is None:
markClass = ast.MarkClassDefinition(location, name)
self.doc_.markClasses[name] = markClass
for glyph in glyphs:
markClass.anchors[glyph] = anchor
markClass.glyphLocations[glyph] = location
def is_next_glyphclass_(self):
return (self.next_token_ == "[" or
self.next_token_type_ in (Lexer.GLYPHCLASS, Lexer.NAME))
def parse_position_(self, enumerated, vertical):
assert self.cur_token_ in {"position", "pos"}
location = self.cur_token_location_
if self.next_token_ == "cursive": # GPOS type 3
self.expect_keyword_("cursive")
if enumerated:
raise FeatureLibError(
'"enumerate" is not allowed with '
'cursive attachment positioning',
location)
glyphclass = self.parse_glyphclass_(accept_glyphname=True)
entryAnchor = self.parse_anchor_()
exitAnchor = self.parse_anchor_()
self.expect_symbol_(";")
return ast.CursiveAttachmentPositioning(
location, glyphclass, entryAnchor, exitAnchor)
if self.next_token_ == "base": # GPOS type 4
self.expect_keyword_("base")
if enumerated:
raise FeatureLibError(
'"enumerate" is not allowed with '
'mark-to-base attachment positioning',
location)
base = self.parse_glyphclass_(accept_glyphname=True)
marks = []
while self.next_token_ != ";":
anchor = self.parse_anchor_()
self.expect_keyword_("mark")
markClass = self.expect_markClass_reference_()
marks.append((anchor, markClass))
self.expect_symbol_(";")
return ast.MarkToBaseAttachmentPositioning(location, base, marks)
gc2, value2 = None, None
gc1 = self.parse_glyphclass_(accept_glyphname=True)
if self.is_next_glyphclass_():
# Pair positioning, format B: 'pos' gc1 gc2 value1
gc2 = self.parse_glyphclass_(accept_glyphname=True)
value1 = self.parse_valuerecord_(vertical)
if self.next_token_ != ";" and gc2 is None:
# Pair positioning, format A: 'pos' gc1 value1 gc2 value2
gc2 = self.parse_glyphclass_(accept_glyphname=True)
value2 = self.parse_valuerecord_(vertical)
self.expect_symbol_(";")
if gc2 is None:
if enumerated:
raise FeatureLibError(
'"enumerate" is only allowed with pair positionings',
self.cur_token_location_)
return ast.SingleAdjustmentPositioning(location, gc1, value1)
else:
return ast.PairAdjustmentPositioning(location, enumerated,
gc1, value1, gc2, value2)
def parse_script_(self):
assert self.is_cur_keyword_("script")
location, script = self.cur_token_location_, self.expect_script_tag_()
self.expect_symbol_(";")
return ast.ScriptStatement(location, script)
def parse_substitute_(self):
assert self.cur_token_ in {"substitute", "sub", "reversesub", "rsub"}
location = self.cur_token_location_
reverse = self.cur_token_ in {"reversesub", "rsub"}
old_prefix, old, lookups, old_suffix = self.parse_glyph_pattern_()
new = []
if self.next_token_ == "by":
keyword = self.expect_keyword_("by")
while self.next_token_ != ";":
new.append(self.parse_glyphclass_(accept_glyphname=True))
elif self.next_token_ == "from":
keyword = self.expect_keyword_("from")
new = [self.parse_glyphclass_(accept_glyphname=False)]
else:
keyword = None
self.expect_symbol_(";")
if len(new) is 0 and not any(lookups):
raise FeatureLibError(
'Expected "by", "from" or explicit lookup references',
self.cur_token_location_)
# GSUB lookup type 3: Alternate substitution.
# Format: "substitute a from [a.1 a.2 a.3];"
if keyword == "from":
if reverse:
raise FeatureLibError(
'Reverse chaining substitutions do not support "from"',
location)
if len(old) != 1 or len(old[0]) != 1:
raise FeatureLibError(
'Expected a single glyph before "from"',
location)
if len(new) != 1:
raise FeatureLibError(
'Expected a single glyphclass after "from"',
location)
return ast.AlternateSubstitution(location, list(old[0])[0], new[0])
num_lookups = len([l for l in lookups if l is not None])
# GSUB lookup type 1: Single substitution.
# Format A: "substitute a by a.sc;"
# Format B: "substitute [one.fitted one.oldstyle] by one;"
# Format C: "substitute [a-d] by [A.sc-D.sc];"
if (not reverse and len(old_prefix) == 0 and len(old_suffix) == 0 and
len(old) == 1 and len(new) == 1 and num_lookups == 0):
glyphs, replacements = sorted(list(old[0])), sorted(list(new[0]))
if len(replacements) == 1:
replacements = replacements * len(glyphs)
if len(glyphs) != len(replacements):
raise FeatureLibError(
'Expected a glyph class with %d elements after "by", '
'but found a glyph class with %d elements' %
(len(glyphs), len(replacements)), location)
return ast.SingleSubstitution(location,
dict(zip(glyphs, replacements)))
# GSUB lookup type 2: Multiple substitution.
# Format: "substitute f_f_i by f f i;"
if (not reverse and len(old_prefix) == 0 and len(old_suffix) == 0 and
len(old) == 1 and len(old[0]) == 1 and
len(new) > 1 and max([len(n) for n in new]) == 1 and
num_lookups == 0):
return ast.MultipleSubstitution(location, tuple(old[0])[0],
tuple([list(n)[0] for n in new]))
# GSUB lookup type 4: Ligature substitution.
# Format: "substitute f f i by f_f_i;"
if (not reverse and len(old_prefix) == 0 and len(old_suffix) == 0 and
len(old) > 1 and len(new) == 1 and len(new[0]) == 1 and
num_lookups == 0):
return ast.LigatureSubstitution(location, old, list(new[0])[0])
# GSUB lookup type 8: Reverse chaining substitution.
if reverse:
if len(old) != 1:
raise FeatureLibError(
"In reverse chaining single substitutions, "
"only a single glyph or glyph class can be replaced",
location)
if len(new) != 1:
raise FeatureLibError(
'In reverse chaining single substitutions, '
'the replacement (after "by") must be a single glyph '
'or glyph class', location)
if num_lookups != 0:
raise FeatureLibError(
"Reverse chaining substitutions cannot call named lookups",
location)
glyphs, replacements = sorted(list(old[0])), sorted(list(new[0]))
if len(replacements) == 1:
replacements = replacements * len(glyphs)
if len(glyphs) != len(replacements):
raise FeatureLibError(
'Expected a glyph class with %d elements after "by", '
'but found a glyph class with %d elements' %
(len(glyphs), len(replacements)), location)
return ast.ReverseChainingSingleSubstitution(
location, old_prefix, old_suffix,
dict(zip(glyphs, replacements)))
rule = ast.SubstitutionRule(location, old, new)
rule.old_prefix, rule.old_suffix = old_prefix, old_suffix
rule.lookups = lookups
rule.reverse = reverse
return rule
def parse_subtable_(self):
assert self.is_cur_keyword_("subtable")
location = self.cur_token_location_
self.expect_symbol_(";")
return ast.SubtableStatement(location)
def parse_device_(self):
result = None
self.expect_symbol_("<")
self.expect_keyword_("device")
if self.next_token_ == "NULL":
self.expect_keyword_("NULL")
else:
result = [(self.expect_number_(), self.expect_number_())]
while self.next_token_ == ",":
self.expect_symbol_(",")
result.append((self.expect_number_(), self.expect_number_()))
result = tuple(result) # make it hashable
self.expect_symbol_(">")
return result
def parse_valuerecord_(self, vertical):
if self.next_token_type_ is Lexer.NUMBER:
number, location = self.expect_number_(), self.cur_token_location_
if vertical:
val = ast.ValueRecord(location, 0, 0, 0, number,
None, None, None, None)
else:
val = ast.ValueRecord(location, 0, 0, number, 0,
None, None, None, None)
return val
self.expect_symbol_("<")
location = self.cur_token_location_
if self.next_token_type_ is Lexer.NAME:
name = self.expect_name_()
if name == "NULL":
self.expect_symbol_(">")
return None
vrd = self.valuerecords_.resolve(name)
if vrd is None:
raise FeatureLibError("Unknown valueRecordDef \"%s\"" % name,
self.cur_token_location_)
value = vrd.value
xPlacement, yPlacement = (value.xPlacement, value.yPlacement)
xAdvance, yAdvance = (value.xAdvance, value.yAdvance)
else:
xPlacement, yPlacement, xAdvance, yAdvance = (
self.expect_number_(), self.expect_number_(),
self.expect_number_(), self.expect_number_())
if self.next_token_ == "<":
xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice = (
self.parse_device_(), self.parse_device_(),
self.parse_device_(), self.parse_device_())
allDeltas = sorted([
delta
for size, delta
in (xPlaDevice if xPlaDevice else ()) +
(yPlaDevice if yPlaDevice else ()) +
(xAdvDevice if xAdvDevice else ()) +
(yAdvDevice if yAdvDevice else ())])
if allDeltas[0] < -128 or allDeltas[-1] > 127:
raise FeatureLibError(
"Device value out of valid range (-128..127)",
self.cur_token_location_)
else:
xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice = (
None, None, None, None)
self.expect_symbol_(">")
return ast.ValueRecord(
location, xPlacement, yPlacement, xAdvance, yAdvance,
xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice)
def parse_valuerecord_definition_(self, vertical):
assert self.is_cur_keyword_("valueRecordDef")
location = self.cur_token_location_
value = self.parse_valuerecord_(vertical)
name = self.expect_name_()
self.expect_symbol_(";")
vrd = ast.ValueRecordDefinition(location, name, value)
self.valuerecords_.define(name, vrd)
return vrd
def parse_languagesystem_(self):
assert self.cur_token_ == "languagesystem"
location = self.cur_token_location_
script = self.expect_script_tag_()
language = self.expect_language_tag_()
self.expect_symbol_(";")
if script == "DFLT" and language != "dflt":
raise FeatureLibError(
'For script "DFLT", the language must be "dflt"',
self.cur_token_location_)
return ast.LanguageSystemStatement(location, script, language)
def parse_feature_block_(self):
assert self.cur_token_ == "feature"
location = self.cur_token_location_
tag = self.expect_tag_()
vertical = (tag == "vkrn")
use_extension = False
if self.next_token_ == "useExtension":
self.expect_keyword_("useExtension")
use_extension = True
block = ast.FeatureBlock(location, tag, use_extension)
self.parse_block_(block, vertical)
return block
def parse_block_(self, block, vertical):
self.expect_symbol_("{")
for symtab in self.symbol_tables_:
symtab.enter_scope()
statements = block.statements
while self.next_token_ != "}":
self.advance_lexer_()
if self.cur_token_type_ is Lexer.GLYPHCLASS:
statements.append(self.parse_glyphclass_definition_())
elif self.is_cur_keyword_("anchorDef"):
statements.append(self.parse_anchordef_())
elif self.is_cur_keyword_({"enum", "enumerate"}):
statements.append(self.parse_enumerate_(vertical=vertical))
elif self.is_cur_keyword_("ignore"):
statements.append(self.parse_ignore_())
elif self.is_cur_keyword_("language"):
statements.append(self.parse_language_())
elif self.is_cur_keyword_("lookup"):
statements.append(self.parse_lookup_(vertical))
elif self.is_cur_keyword_("markClass"):
self.parse_markClass_()
elif self.is_cur_keyword_({"pos", "position"}):
statements.append(
self.parse_position_(enumerated=False, vertical=vertical))
elif self.is_cur_keyword_("script"):
statements.append(self.parse_script_())
elif (self.is_cur_keyword_({"sub", "substitute",
"rsub", "reversesub"})):
statements.append(self.parse_substitute_())
elif self.is_cur_keyword_("subtable"):
statements.append(self.parse_subtable_())
elif self.is_cur_keyword_("valueRecordDef"):
statements.append(self.parse_valuerecord_definition_(vertical))
else:
raise FeatureLibError(
"Expected glyph class definition or statement",
self.cur_token_location_)
self.expect_symbol_("}")
for symtab in self.symbol_tables_:
symtab.exit_scope()
name = self.expect_name_()
if name != block.name.strip():
raise FeatureLibError("Expected \"%s\"" % block.name.strip(),
self.cur_token_location_)
self.expect_symbol_(";")
def is_cur_keyword_(self, k):
if self.cur_token_type_ is Lexer.NAME:
if isinstance(k, type("")): # basestring is gone in Python3
return self.cur_token_ == k
else:
return self.cur_token_ in k
return False
def expect_class_name_(self):
self.advance_lexer_()
if self.cur_token_type_ is not Lexer.GLYPHCLASS:
raise FeatureLibError("Expected @NAME", self.cur_token_location_)
return self.cur_token_
def expect_markClass_reference_(self):
name = self.expect_class_name_()
markClass = self.doc_.markClasses.get(name)
if markClass is None:
raise FeatureLibError("Unknown markClass @%s" % name,
self.cur_token_location_)
return markClass
def expect_tag_(self):
self.advance_lexer_()
if self.cur_token_type_ is not Lexer.NAME:
raise FeatureLibError("Expected a tag", self.cur_token_location_)
if len(self.cur_token_) > 4:
raise FeatureLibError("Tags can not be longer than 4 characters",
self.cur_token_location_)
return (self.cur_token_ + " ")[:4]
def expect_script_tag_(self):
tag = self.expect_tag_()
if tag == "dflt":
raise FeatureLibError(
'"dflt" is not a valid script tag; use "DFLT" instead',
self.cur_token_location_)
return tag
def expect_language_tag_(self):
tag = self.expect_tag_()
if tag == "DFLT":
raise FeatureLibError(
'"DFLT" is not a valid language tag; use "dflt" instead',
self.cur_token_location_)
return tag
def expect_symbol_(self, symbol):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.SYMBOL and self.cur_token_ == symbol:
return symbol
raise FeatureLibError("Expected '%s'" % symbol,
self.cur_token_location_)
def expect_keyword_(self, keyword):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME and self.cur_token_ == keyword:
return self.cur_token_
raise FeatureLibError("Expected \"%s\"" % keyword,
self.cur_token_location_)
def expect_name_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME:
return self.cur_token_
raise FeatureLibError("Expected a name", self.cur_token_location_)
def expect_number_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NUMBER:
return self.cur_token_
raise FeatureLibError("Expected a 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_)
try:
(self.next_token_type_, self.next_token_,
self.next_token_location_) = self.lexer_.next()
except StopIteration:
self.next_token_type_, self.next_token_ = (None, None)
@staticmethod
def reverse_string_(s):
"""'abc' --> 'cba'"""
return ''.join(reversed(list(s)))
def make_glyph_range_(self, location, start, limit):
"""("a.sc", "d.sc") --> {"a.sc", "b.sc", "c.sc", "d.sc"}"""
result = set()
if len(start) != len(limit):
raise FeatureLibError(
"Bad range: \"%s\" and \"%s\" should have the same length" %
(start, limit), location)
rev = self.reverse_string_
prefix = os.path.commonprefix([start, limit])
suffix = rev(os.path.commonprefix([rev(start), rev(limit)]))
if len(suffix) > 0:
start_range = start[len(prefix):-len(suffix)]
limit_range = limit[len(prefix):-len(suffix)]
else:
start_range = start[len(prefix):]
limit_range = limit[len(prefix):]
if start_range >= limit_range:
raise FeatureLibError(
"Start of range must be smaller than its end",
location)
uppercase = re.compile(r'^[A-Z]$')
if uppercase.match(start_range) and uppercase.match(limit_range):
for c in range(ord(start_range), ord(limit_range) + 1):
result.add("%s%c%s" % (prefix, c, suffix))
return result
lowercase = re.compile(r'^[a-z]$')
if lowercase.match(start_range) and lowercase.match(limit_range):
for c in range(ord(start_range), ord(limit_range) + 1):
result.add("%s%c%s" % (prefix, c, suffix))
return result
digits = re.compile(r'^[0-9]{1,3}$')
if digits.match(start_range) and digits.match(limit_range):
for i in range(int(start_range, 10), int(limit_range, 10) + 1):
number = ("000" + str(i))[-len(start_range):]
result.add("%s%s%s" % (prefix, number, suffix))
return result
raise FeatureLibError("Bad range: \"%s-%s\"" % (start, limit),
location)
class Parser(object):
def __init__(self, path):
self.doc_ = ast.FeatureFile()
self.anchors_ = SymbolTable()
self.glyphclasses_ = SymbolTable()
self.lookups_ = SymbolTable()
self.valuerecords_ = SymbolTable()
self.symbol_tables_ = {
self.anchors_, self.glyphclasses_,
self.lookups_, self.valuerecords_
}
self.next_token_type_, self.next_token_ = (None, None)
self.next_token_location_ = None
self.lexer_ = IncludingLexer(path)
self.advance_lexer_()
def parse(self):
statements = self.doc_.statements
while self.next_token_type_ is not None:
self.advance_lexer_()
if self.cur_token_type_ is Lexer.GLYPHCLASS:
statements.append(self.parse_glyphclass_definition_())
elif self.is_cur_keyword_("anchorDef"):
statements.append(self.parse_anchordef_())
elif self.is_cur_keyword_("languagesystem"):
statements.append(self.parse_languagesystem_())
elif self.is_cur_keyword_("lookup"):
statements.append(self.parse_lookup_(vertical=False))
elif self.is_cur_keyword_("feature"):
statements.append(self.parse_feature_block_())
elif self.is_cur_keyword_("valueRecordDef"):
statements.append(
self.parse_valuerecord_definition_(vertical=False))
else:
raise FeatureLibError("Expected feature, languagesystem, "
"lookup, or glyph class definition",
self.cur_token_location_)
return self.doc_
def parse_anchordef_(self):
assert self.is_cur_keyword_("anchorDef")
location = self.cur_token_location_
x, y = self.expect_number_(), self.expect_number_()
contourpoint = None
if self.next_token_ == "contourpoint":
self.expect_keyword_("contourpoint")
contourpoint = self.expect_number_()
name = self.expect_name_()
self.expect_symbol_(";")
anchordef = ast.AnchorDefinition(location, name, x, y, contourpoint)
self.anchors_.define(name, anchordef)
return anchordef
def parse_glyphclass_definition_(self):
location, name = self.cur_token_location_, self.cur_token_
self.expect_symbol_("=")
glyphs = self.parse_glyphclass_(accept_glyphname=False)
self.expect_symbol_(";")
if self.glyphclasses_.resolve(name) is not None:
raise FeatureLibError("Glyph class @%s already defined" % name,
location)
glyphclass = ast.GlyphClassDefinition(location, name, glyphs)
self.glyphclasses_.define(name, glyphclass)
return glyphclass
def parse_glyphclass_(self, accept_glyphname):
result = set()
if accept_glyphname and self.next_token_type_ is Lexer.NAME:
result.add(self.expect_name_())
return result
if self.next_token_type_ is Lexer.GLYPHCLASS:
self.advance_lexer_()
gc = self.glyphclasses_.resolve(self.cur_token_)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % self.cur_token_,
self.cur_token_location_)
result.update(gc.glyphs)
return result
self.expect_symbol_("[")
while self.next_token_ != "]":
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME:
if self.next_token_ == "-":
range_location_ = self.cur_token_location_
range_start = self.cur_token_
self.expect_symbol_("-")
range_end = self.expect_name_()
result.update(self.make_glyph_range_(range_location_,
range_start,
range_end))
else:
result.add(self.cur_token_)
elif self.cur_token_type_ is Lexer.GLYPHCLASS:
gc = self.glyphclasses_.resolve(self.cur_token_)
if gc is None:
raise FeatureLibError(
"Unknown glyph class @%s" % self.cur_token_,
self.cur_token_location_)
result.update(gc.glyphs)
else:
raise FeatureLibError(
"Expected glyph name, glyph range, "
"or glyph class reference",
self.cur_token_location_)
self.expect_symbol_("]")
return result
def parse_glyph_pattern_(self):
prefix, glyphs, lookups, suffix = ([], [], [], [])
while self.next_token_ not in {"by", "from", ";"}:
gc = self.parse_glyphclass_(accept_glyphname=True)
marked = False
if self.next_token_ == "'":
self.expect_symbol_("'")
marked = True
if marked:
glyphs.append(gc)
elif glyphs:
suffix.append(gc)
else:
prefix.append(gc)
lookup = None
if self.next_token_ == "lookup":
self.expect_keyword_("lookup")
if not marked:
raise FeatureLibError(
"Lookups can only follow marked glyphs",
self.cur_token_location_)
lookup_name = self.expect_name_()
lookup = self.lookups_.resolve(lookup_name)
if lookup is None:
raise FeatureLibError(
'Unknown lookup "%s"' % lookup_name,
self.cur_token_location_)
if marked:
lookups.append(lookup)
if not glyphs and not suffix: # eg., "sub f f i by"
assert lookups == []
return ([], prefix, [None] * len(prefix), [])
else:
return (prefix, glyphs, lookups, suffix)
def parse_ignore_(self):
assert self.is_cur_keyword_("ignore")
location = self.cur_token_location_
self.advance_lexer_()
if self.cur_token_ in ["substitute", "sub"]:
prefix, glyphs, lookups, suffix = self.parse_glyph_pattern_()
self.expect_symbol_(";")
return ast.IgnoreSubstitutionRule(location, prefix, glyphs, suffix)
raise FeatureLibError(
"Expected \"substitute\"", self.next_token_location_)
def parse_language_(self):
assert self.is_cur_keyword_("language")
location = self.cur_token_location_
language = self.expect_language_tag_()
include_default, required = (True, False)
if self.next_token_ in {"exclude_dflt", "include_dflt"}:
include_default = (self.expect_name_() == "include_dflt")
if self.next_token_ == "required":
self.expect_keyword_("required")
required = True
self.expect_symbol_(";")
return ast.LanguageStatement(location, language,
include_default, required)
def parse_lookup_(self, vertical):
assert self.is_cur_keyword_("lookup")
location, name = self.cur_token_location_, self.expect_name_()
if self.next_token_ == ";":
lookup = self.lookups_.resolve(name)
if lookup is None:
raise FeatureLibError("Unknown lookup \"%s\"" % name,
self.cur_token_location_)
self.expect_symbol_(";")
return ast.LookupReferenceStatement(location, lookup)
use_extension = False
if self.next_token_ == "useExtension":
self.expect_keyword_("useExtension")
use_extension = True
block = ast.LookupBlock(location, name, use_extension)
self.parse_block_(block, vertical)
self.lookups_.define(name, block)
return block
def parse_script_(self):
assert self.is_cur_keyword_("script")
location, script = self.cur_token_location_, self.expect_script_tag_()
self.expect_symbol_(";")
return ast.ScriptStatement(location, script)
def parse_substitute_(self):
assert self.cur_token_ in {"substitute", "sub"}
location = self.cur_token_location_
old_prefix, old, lookups, old_suffix = self.parse_glyph_pattern_()
new = []
if self.next_token_ == "by":
keyword = self.expect_keyword_("by")
while self.next_token_ != ";":
new.append(self.parse_glyphclass_(accept_glyphname=True))
elif self.next_token_ == "from":
keyword = self.expect_keyword_("from")
new = [self.parse_glyphclass_(accept_glyphname=False)]
else:
keyword = None
self.expect_symbol_(";")
if len(new) is 0 and not any(lookups):
raise FeatureLibError(
'Expected "by", "from" or explicit lookup references',
self.cur_token_location_)
# GSUB lookup type 3: Alternate substitution.
# Format: "substitute a from [a.1 a.2 a.3];"
if keyword == "from":
if len(old) != 1 or len(old[0]) != 1:
raise FeatureLibError(
'Expected a single glyph before "from"',
location)
if len(new) != 1:
raise FeatureLibError(
'Expected a single glyphclass after "from"',
location)
return ast.AlternateSubstitution(location, list(old[0])[0], new[0])
num_lookups = len([l for l in lookups if l is not None])
# GSUB lookup type 1: Single substitution.
# Format A: "substitute a by a.sc;"
# Format B: "substitute [one.fitted one.oldstyle] by one;"
# Format C: "substitute [a-d] by [A.sc-D.sc];"
if (len(old_prefix) == 0 and len(old_suffix) == 0 and
len(old) == 1 and len(new) == 1 and num_lookups == 0):
glyphs, replacements = sorted(list(old[0])), sorted(list(new[0]))
if len(replacements) == 1:
replacements = replacements * len(glyphs)
if len(glyphs) != len(replacements):
raise FeatureLibError(
'Expected a glyph class with %d elements after "by", '
'but found a glyph class with %d elements' %
(len(glyphs), len(replacements)), location)
return ast.SingleSubstitution(location,
dict(zip(glyphs, replacements)))
# GSUB lookup type 2: Multiple substitution.
# Format: "substitute f_f_i by f f i;"
if (len(old_prefix) == 0 and len(old_suffix) == 0 and
len(old) == 1 and len(old[0]) == 1 and
len(new) > 1 and max([len(n) for n in new]) == 1 and
num_lookups == 0):
return ast.MultipleSubstitution(location, tuple(old[0])[0],
tuple([list(n)[0] for n in new]))
# GSUB lookup type 4: Ligature substitution.
# Format: "substitute f f i by f_f_i;"
if (len(old_prefix) == 0 and len(old_suffix) == 0 and
len(old) > 1 and len(new) == 1 and len(new[0]) == 1 and
num_lookups == 0):
return ast.LigatureSubstitution(location, old, list(new[0])[0])
rule = ast.SubstitutionRule(location, old, new)
rule.old_prefix, rule.old_suffix = old_prefix, old_suffix
rule.lookups = lookups
return rule
def parse_subtable_(self):
assert self.is_cur_keyword_("subtable")
location = self.cur_token_location_
self.expect_symbol_(";")
return ast.SubtableStatement(location)
def parse_valuerecord_(self, vertical):
if self.next_token_type_ is Lexer.NUMBER:
number, location = self.expect_number_(), self.cur_token_location_
if vertical:
val = ast.ValueRecord(location, 0, 0, 0, number)
else:
val = ast.ValueRecord(location, 0, 0, number, 0)
return val
self.expect_symbol_("<")
location = self.cur_token_location_
if self.next_token_type_ is Lexer.NAME:
name = self.expect_name_()
vrd = self.valuerecords_.resolve(name)
if vrd is None:
raise FeatureLibError("Unknown valueRecordDef \"%s\"" % name,
self.cur_token_location_)
value = vrd.value
xPlacement, yPlacement = (value.xPlacement, value.yPlacement)
xAdvance, yAdvance = (value.xAdvance, value.yAdvance)
else:
xPlacement, yPlacement, xAdvance, yAdvance = (
self.expect_number_(), self.expect_number_(),
self.expect_number_(), self.expect_number_())
self.expect_symbol_(">")
return ast.ValueRecord(
location, xPlacement, yPlacement, xAdvance, yAdvance)
def parse_valuerecord_definition_(self, vertical):
assert self.is_cur_keyword_("valueRecordDef")
location = self.cur_token_location_
value = self.parse_valuerecord_(vertical)
name = self.expect_name_()
self.expect_symbol_(";")
vrd = ast.ValueRecordDefinition(location, name, value)
self.valuerecords_.define(name, vrd)
return vrd
def parse_languagesystem_(self):
assert self.cur_token_ == "languagesystem"
location = self.cur_token_location_
script = self.expect_script_tag_()
language = self.expect_language_tag_()
self.expect_symbol_(";")
if script == "DFLT" and language != "dflt":
raise FeatureLibError(
'For script "DFLT", the language must be "dflt"',
self.cur_token_location_)
return ast.LanguageSystemStatement(location, script, language)
def parse_feature_block_(self):
assert self.cur_token_ == "feature"
location = self.cur_token_location_
tag = self.expect_tag_()
vertical = (tag == "vkrn")
use_extension = False
if self.next_token_ == "useExtension":
self.expect_keyword_("useExtension")
use_extension = True
block = ast.FeatureBlock(location, tag, use_extension)
self.parse_block_(block, vertical)
return block
def parse_block_(self, block, vertical):
self.expect_symbol_("{")
for symtab in self.symbol_tables_:
symtab.enter_scope()
statements = block.statements
while self.next_token_ != "}":
self.advance_lexer_()
if self.cur_token_type_ is Lexer.GLYPHCLASS:
statements.append(self.parse_glyphclass_definition_())
elif self.is_cur_keyword_("anchorDef"):
statements.append(self.parse_anchordef_())
elif self.is_cur_keyword_("ignore"):
statements.append(self.parse_ignore_())
elif self.is_cur_keyword_("language"):
statements.append(self.parse_language_())
elif self.is_cur_keyword_("lookup"):
statements.append(self.parse_lookup_(vertical))
elif self.is_cur_keyword_("script"):
statements.append(self.parse_script_())
elif (self.is_cur_keyword_("substitute") or
self.is_cur_keyword_("sub")):
statements.append(self.parse_substitute_())
elif self.is_cur_keyword_("subtable"):
statements.append(self.parse_subtable_())
elif self.is_cur_keyword_("valueRecordDef"):
statements.append(self.parse_valuerecord_definition_(vertical))
else:
raise FeatureLibError(
"Expected glyph class definition or statement",
self.cur_token_location_)
self.expect_symbol_("}")
for symtab in self.symbol_tables_:
symtab.exit_scope()
name = self.expect_name_()
if name != block.name.strip():
raise FeatureLibError("Expected \"%s\"" % block.name.strip(),
self.cur_token_location_)
self.expect_symbol_(";")
def is_cur_keyword_(self, k):
return (self.cur_token_type_ is Lexer.NAME) and (self.cur_token_ == k)
def expect_tag_(self):
self.advance_lexer_()
if self.cur_token_type_ is not Lexer.NAME:
raise FeatureLibError("Expected a tag", self.cur_token_location_)
if len(self.cur_token_) > 4:
raise FeatureLibError("Tags can not be longer than 4 characters",
self.cur_token_location_)
return (self.cur_token_ + " ")[:4]
def expect_script_tag_(self):
tag = self.expect_tag_()
if tag == "dflt":
raise FeatureLibError(
'"dflt" is not a valid script tag; use "DFLT" instead',
self.cur_token_location_)
return tag
def expect_language_tag_(self):
tag = self.expect_tag_()
if tag == "DFLT":
raise FeatureLibError(
'"DFLT" is not a valid language tag; use "dflt" instead',
self.cur_token_location_)
return tag
def expect_symbol_(self, symbol):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.SYMBOL and self.cur_token_ == symbol:
return symbol
raise FeatureLibError("Expected '%s'" % symbol,
self.cur_token_location_)
def expect_keyword_(self, keyword):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME and self.cur_token_ == keyword:
return self.cur_token_
raise FeatureLibError("Expected \"%s\"" % keyword,
self.cur_token_location_)
def expect_name_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NAME:
return self.cur_token_
raise FeatureLibError("Expected a name", self.cur_token_location_)
def expect_number_(self):
self.advance_lexer_()
if self.cur_token_type_ is Lexer.NUMBER:
return self.cur_token_
raise FeatureLibError("Expected a 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_)
try:
(self.next_token_type_, self.next_token_,
self.next_token_location_) = self.lexer_.next()
except StopIteration:
self.next_token_type_, self.next_token_ = (None, None)
@staticmethod
def reverse_string_(s):
"""'abc' --> 'cba'"""
return ''.join(reversed(list(s)))
def make_glyph_range_(self, location, start, limit):
"""("a.sc", "d.sc") --> {"a.sc", "b.sc", "c.sc", "d.sc"}"""
result = set()
if len(start) != len(limit):
raise FeatureLibError(
"Bad range: \"%s\" and \"%s\" should have the same length" %
(start, limit), location)
rev = self.reverse_string_
prefix = os.path.commonprefix([start, limit])
suffix = rev(os.path.commonprefix([rev(start), rev(limit)]))
if len(suffix) > 0:
start_range = start[len(prefix):-len(suffix)]
limit_range = limit[len(prefix):-len(suffix)]
else:
start_range = start[len(prefix):]
limit_range = limit[len(prefix):]
if start_range >= limit_range:
raise FeatureLibError(
"Start of range must be smaller than its end",
location)
uppercase = re.compile(r'^[A-Z]$')
if uppercase.match(start_range) and uppercase.match(limit_range):
for c in range(ord(start_range), ord(limit_range) + 1):
result.add("%s%c%s" % (prefix, c, suffix))
return result
lowercase = re.compile(r'^[a-z]$')
if lowercase.match(start_range) and lowercase.match(limit_range):
for c in range(ord(start_range), ord(limit_range) + 1):
result.add("%s%c%s" % (prefix, c, suffix))
return result
digits = re.compile(r'^[0-9]{1,3}$')
if digits.match(start_range) and digits.match(limit_range):
for i in range(int(start_range, 10), int(limit_range, 10) + 1):
number = ("000" + str(i))[-len(start_range):]
result.add("%s%s%s" % (prefix, number, suffix))
return result
raise FeatureLibError("Bad range: \"%s-%s\"" % (start, limit),
location)