diff options
Diffstat (limited to 'text/syllabic.py')
| -rw-r--r-- | text/syllabic.py | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/text/syllabic.py b/text/syllabic.py index 6eb7c93..4a79869 100644 --- a/text/syllabic.py +++ b/text/syllabic.py @@ -12,6 +12,10 @@ HARFBUZZ_SRC is HarfBuzz 10.2.0's src/ directory; what is read from it: read cell for cell (Unicode here is 15.1: the table is taken as HarfBuzz has it). Khmer and Myanmar read the same table. +- Each character's category for the Universal Shaping Engine: hb-ot- + shaper-use-table.hh, whose arrays and lookup (gen-use-table.py's) are + carried over as they are, the categories named in them resolved. + - The syllable machines: hb-ot-shaper-*-machine.rl, the Ragel grammars. This compiles each to a DFA with Ragel's scanner semantics (the longest match from each position, ties to the pattern listed first), its symbols @@ -27,7 +31,7 @@ import sys from pathlib import Path HB = Path(sys.argv[1] if len(sys.argv) > 1 else '.') -MACHINES = ['indic', 'khmer', 'myanmar'] +MACHINES = ['indic', 'khmer', 'myanmar', 'use'] ALPHABET = 64 # categories past 63 are folded into 63, which only `any` takes @@ -277,6 +281,22 @@ def runs_of(cells): return runs +def use_table(grammar): + """HarfBuzz's USE lookup: its arrays (categories resolved to numbers) + and its expression, as C.""" + text = (HB / 'hb-ot-shaper-use-table.hh').read_text() + part = text[text.index('#ifndef HB_OPTIMIZE_SIZE'):text.index('#else')] + arrays = [] + for kind, name, n, body in re.findall(r'static const (uint8_t|uint16_t)\s+(hb_use_\w+)\[(\d+)\] =\s*\{(.*?)\};', + part, re.S): + values = [int(t) if t.isdigit() else grammar.symbols[t] for t in re.findall(r'[A-Za-z_]\w*|\d+', body)] + assert len(values) == int(n), name + arrays.append((kind, name.replace('hb_use_', 'use_'), values)) + expression = re.search(r'return (u<.*?);\n', part).group(1).replace('hb_use_', 'use_') + assert expression.endswith(':O') + return arrays, expression[:-1] + str(grammar.symbols['O']) + + # ---- Checking against Ragel's machines (hb-ot-shaper-*-machine.hh) def ragel(name): @@ -445,6 +465,24 @@ def main(): out.append(f' return 0x{default[0] | default[1] << 8:04X};') out.append('}') out.append('') + arrays, expression = use_table(grammars['use']) + out.append('/* Each character\'s USE category (hb-ot-shaper-use-table.hh, Unicode 16): HarfBuzz\'s arrays and') + out.append(' * lookup. */') + for kind, name, values in arrays: + out.append(f'static const {kind} {name}[{len(values)}] = {{') + for k in range(0, len(values), 16): + out.append(' ' + ', '.join(str(v) for v in values[k:k + 16]) + ',') + out.append('};') + out.append('static unsigned use_b4(const uint8_t *a, unsigned i) { return (a[i >> 1] >> ((i & 1u) << 2)) & 15u; }') + out.append(f'uint8_t vega_use_category(uint32_t u) {{ return (uint8_t)({expression}); }}') + out.append('') + out.append('/* The categories syllabic.h names are the machines\' own. */') + for name, prefix in (('indic', 'VEGA_OT_'), ('khmer', 'VEGA_OT_'), ('myanmar', 'VEGA_OT_'), ('use', 'VEGA_USE_')): + for symbol, value in sorted(grammars[name].symbols.items()): + if name == 'myanmar' and symbol in ('IV', 'DB', 'GB'): + continue # Myanmar's names for V, N and PLACEHOLDER + out.append(f'_Static_assert({prefix}{symbol.upper()} == {value}, "{name} {symbol}");') + out.append('') out.append('/* The syllable machines: a DFA over classes of symbol; a state\'s accept is') out.append(' * the syllable type it ends, plus one. */') for name in MACHINES: |