File size: 12,456 Bytes
2e4432d | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 | """ICL 0.1 hand-written lexer/parser. No host language parsing or evaluation."""
import bisect, json, re, unicodedata
from .runtime import ICLError
KEYWORDS={'module','import','fn','let','var','if','else','while','limit','return','true','false','type'}
class Parser:
def __init__(self,source):
if not isinstance(source,str) or len(source.encode())>1000000: raise ICLError('SOURCE_LIMIT','source must be UTF-8 text <= 1MB')
for c in source:
if unicodedata.category(c) in ('Cf','Cs') or (ord(c)<32 and c not in '\n\r\t'): raise ICLError('LEX','invisible/control character forbidden')
self.source=source; self.tokens=[]; self.i=0; self.depth=0; self.aliases={}
self.newlines=[-1]+[i for i,c in enumerate(source) if c=='\n']
pattern=re.compile(r'(?P<space>\s+)|(?P<comment>//[^\n]*)|(?P<string>"(?:[^"\\\n]|\\["\\/bfnrt]|\\u[0-9a-fA-F]{4})*")|(?P<float>\d+\.\d+(?:[eE][+-]?\d+)?|\d+[eE][+-]?\d+)|(?P<int>\d+)|(?P<id>[A-Za-z_][A-Za-z_0-9]*)|(?P<op>->|==|!=|<=|>=|&&|\|\||[{}()\[\],;:.+*/%<>=!\-])')
p=0
while p<len(source):
m=pattern.match(source,p)
if not m: raise ICLError('LEX',f'unexpected character {source[p]!r}',self.span(p))
if m.lastgroup in ('int','float') and len(m.group())>128:
raise ICLError('NUMBER_LIMIT','numeric token exceeds 128 characters',self.span(p))
if m.lastgroup not in ('space','comment'): self.tokens.append((m.lastgroup,m.group(),self.span(p)))
p=m.end()
if len(self.tokens)>100000: raise ICLError('SOURCE_LIMIT','too many tokens')
self.tokens.append(('eof','<eof>',self.span(len(source))))
def span(self,p):
line=bisect.bisect_left(self.newlines,p)
return {'line':line,'column':p-self.newlines[line-1],'offset':p}
def peek(self,v=None): return self.tokens[self.i][1] if v is None else self.tokens[self.i][1]==v
def take(self,v=None):
if self.i>=len(self.tokens) or self.tokens[self.i][0]=='eof':
raise ICLError('PARSE','unexpected end of source',self.tokens[-1][2])
t=self.tokens[self.i]
if v is not None and t[1]!=v: raise ICLError('PARSE',f'expected {v}, got {t[1]}',t[2])
self.i+=1; return t
def ident(self):
t=self.take()
if t[0]!='id' or t[1] in KEYWORDS: raise ICLError('PARSE','identifier expected',t[2])
return t[1]
def typ(self):
name=self.ident()
if name in self.aliases:
if self.peek('['):
raise ICLError('TYPE','type alias cannot take arguments')
return self.aliases[name]
if name=='Record' and self.peek('{'):
self.take('{'); fields={}
if self.peek('}'):raise ICLError('TYPE','empty record annotation is unsupported')
while True:
field=self.ident()
if field in fields:raise ICLError('TYPE','duplicate record type field')
self.take(':'); fields[field]=self.typ()
if not self.peek(','):break
self.take(',')
self.take('}')
return 'Record{'+','.join(k+':'+v for k,v in sorted(fields.items()))+'}'
if self.peek('['):
self.take(); args=[]
if not self.peek(']'):
while True:
args.append(self.take()[1] if self.tokens[self.i][0]=='int' else self.typ())
if not self.peek(','): break
self.take(',')
self.take(']'); name+='['+','.join(args)+']'
return name
def parse(self):
self.take('module'); module=self.ident(); self.take(';'); imports=[]; funcs=[]
while self.peek('import'):
self.take(); imports.append(self.ident()); self.take(';')
while self.peek('type'):
self.take('type'); alias=self.ident()
if alias in self.aliases or alias in {'Int64','Float64','Bool','String','Record','Tensor','List','Result','Option','Observer','Context','ProvenanceRef','RecoveryWitness','Capability','Tuple','Exact','Approx','Representation'}:
raise ICLError('TYPE','duplicate or reserved type alias')
self.take('='); target=self.typ(); self.take(';')
from .checker import valid_type
if not valid_type(target):raise ICLError('TYPE','alias must resolve to an already defined type')
self.aliases[alias]=target
while not self.peek('<eof>'):
sp=self.take('fn')[2]; name=self.ident(); self.take('('); params=[]
if not self.peek(')'):
while True:
nm=self.ident(); self.take(':'); params.append([nm,self.typ()])
if not self.peek(','): break
self.take(',')
self.take(')'); self.take('->'); ret=self.typ(); funcs.append({'name':name,'params':params,'return_type':ret,'body':self.block(),'span':sp})
if not funcs: raise ICLError('PARSE','module requires function')
return {'module':module,'imports':imports,'functions':funcs}
def block(self):
self.take('{'); body=[]
while not self.peek('}'):
if self.peek('<eof>'): raise ICLError('PARSE','unterminated block')
body.append(self.stmt())
self.take('}'); return body
def stmt(self):
sp=self.tokens[self.i][2]; v=self.peek()
if v in ('let','var'):
self.take(); nm=self.ident(); tp=None
if self.peek(':'): self.take();tp=self.typ()
self.take('='); ex=self.expr();self.take(';');return {'kind':'let','name':nm,'type':tp,'mutable':v=='var','expr':ex,'span':sp}
if v=='return':
self.take();ex=self.expr();self.take(';');return {'kind':'return','expr':ex,'span':sp}
if v=='if':
self.take();co=self.expr();yes=self.block();no=[]
if self.peek('else'):self.take();no=self.block()
return {'kind':'if','cond':co,'then':yes,'else':no,'span':sp}
if v=='while':
self.take();co=self.expr();self.take('limit');t=self.take()
if t[0]!='int' or not 0<=int(t[1])<=100000:raise ICLError('PARSE','loop limit must be literal 0..100000',t[2])
return {'kind':'while','cond':co,'limit':int(t[1]),'body':self.block(),'span':sp}
if self.tokens[self.i][0]=='id' and self.tokens[self.i+1][1]=='=':
nm=self.ident();self.take('=');ex=self.expr();self.take(';');return {'kind':'assign','name':nm,'expr':ex,'span':sp}
ex=self.expr();self.take(';');return {'kind':'expr','expr':ex,'span':sp}
PREC={'||':1,'&&':2,'==':3,'!=':3,'<':4,'>':4,'<=':4,'>=':4,'+':5,'-':5,'*':6,'/':6,'%':6}
def expr(self,p=0):
self.depth+=1
if self.depth>150:raise ICLError('PARSE_DEPTH','expression nesting exceeds 150')
try:
t=self.take();sp=t[2];v=t[1]
if v=='-' and self.tokens[self.i][0]=='int' and self.tokens[self.i][1]==str(1<<63):
self.take();left={'kind':'literal','value':-(1<<63),'span':sp}
elif v in ('!','-'):left={'kind':'unary','op':v,'expr':self.expr(7),'span':sp}
elif t[0] in ('int','float','string') or v in ('true','false'):
val=json.loads(v) if t[0]=='string' else float(v) if t[0]=='float' else int(v) if t[0]=='int' else v=='true'
if isinstance(val,str) and any(unicodedata.category(c)=='Cs' for c in val):raise ICLError('LEX','unpaired Unicode surrogate forbidden',sp)
left={'kind':'literal','value':val,'span':sp}
elif v=='(':
left=self.expr()
if self.peek(','):
items=[left]
while self.peek(','):self.take();items.append(self.expr())
left={'kind':'tuple','items':items,'span':sp}
self.take(')')
elif v=='[':
items=[]
if not self.peek(']'):
while True:
items.append(self.expr())
if not self.peek(','):break
self.take(',')
self.take(']');left={'kind':'list','items':items,'span':sp}
elif v=='{':
fields={}
if not self.peek('}'):
while True:
k=self.ident()
if k in fields:raise ICLError('PARSE','duplicate field')
self.take(':');fields[k]=self.expr()
if not self.peek(','):break
self.take(',')
self.take('}');left={'kind':'record','fields':fields,'span':sp}
elif t[0]=='id' and v not in KEYWORDS:left={'kind':'var','name':v,'span':sp}
else:raise ICLError('PARSE','expression expected',sp)
while True:
if self.peek('('):
if left['kind'] not in ('var','field'):raise ICLError('PARSE','calls require named function',sp)
name=left['name'] if left['kind']=='var' else left['target']['name']+'.'+left['name'] if left['target']['kind']=='var' else None
if name is None:raise ICLError('PARSE','invalid call target',sp)
self.take();args=[]
if not self.peek(')'):
while True:
args.append(self.expr())
if not self.peek(','):break
self.take(',')
self.take(')');left={'kind':'call','name':name,'args':args,'span':sp};continue
if self.peek('['):
self.take();ix=self.expr();self.take(']');left={'kind':'index','target':left,'index':ix,'span':sp};continue
if self.peek('.'):
self.take();nm=self.ident();left={'kind':'field','target':left,'name':nm,'span':sp};continue
op=self.peek();prec=self.PREC.get(op,-1)
if prec<p:break
self.take();right=self.expr(prec+1);left={'kind':'binary','op':op,'left':left,'right':right,'span':sp}
return left
finally:self.depth-=1
def parse(source):
try:return Parser(source).parse()
except RecursionError:raise ICLError('PARSE_DEPTH','parser recursion limit')
except IndexError:raise ICLError('PARSE','unexpected end of source')
except (ValueError,OverflowError):raise ICLError('LEX','invalid or oversized literal')
def canonical_ast(node):
if isinstance(node,dict):return {k:canonical_ast(v) for k,v in sorted(node.items()) if k not in ('span','inferred_type','effects')}
if isinstance(node,list):return [canonical_ast(v) for v in node]
return node
def pretty(program):
def e(x):
k=x['kind']
if k=='literal':return json.dumps(x['value'],ensure_ascii=False)
if k=='var':return x['name']
if k=='binary':return '('+e(x['left'])+' '+x['op']+' '+e(x['right'])+')'
if k=='unary':return '('+x['op']+e(x['expr'])+')'
if k=='call':return x['name']+'('+', '.join(e(a) for a in x['args'])+')'
if k in ('list','tuple'):return ('[' if k=='list' else '(')+', '.join(e(a) for a in x['items'])+(']' if k=='list' else ')')
if k=='record':return '{'+', '.join(n+': '+e(a) for n,a in x['fields'].items())+'}'
if k=='index':return e(x['target'])+'['+e(x['index'])+']'
if k=='field':return e(x['target'])+'.'+x['name']
raise ICLError('UNSUPPORTED_OP',k)
def b(ss):
out=[]
for s in ss:
k=s['kind']
if k=='let':out.append(('var ' if s['mutable'] else 'let ')+s['name']+(':'+s['type'] if s.get('type') else '')+' = '+e(s['expr'])+';')
elif k=='assign':out.append(s['name']+' = '+e(s['expr'])+';')
elif k=='return':out.append('return '+e(s['expr'])+';')
elif k=='expr':out.append(e(s['expr'])+';')
elif k=='if':out.append('if '+e(s['cond'])+' { '+b(s['then'])+' } else { '+b(s['else'])+' }')
elif k=='while':out.append('while '+e(s['cond'])+' limit '+str(s['limit'])+' { '+b(s['body'])+' }')
return ' '.join(out)
return 'module '+program['module']+';\n'+''.join('import '+m+';\n' for m in program['imports'])+'\n'.join('fn '+f['name']+'('+', '.join(n+': '+t for n,t in f['params'])+') -> '+f['return_type']+' { '+b(f['body'])+' }' for f in program['functions'])+'\n'
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