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from .structs import *
from .exceptions import ParseError
def parseDef(token, prev, tokens):
if len(tokens) < 2:
raise ParseError("invalid def", token.line)
elif tokens[0].type_ != TokenType.SYMBOL:
raise ParseError("'def' must take a symbol", token.line)
sym, inc = parseSymbol(tokens[0], token, tokens[1:])
return NebDef(sym), inc + 1
def parseLambda(token, prev, tokens):
# lambda [type] ( [arg] [&] ) [(expr)]
# func <name> [type] ( [arg] [&] ) [(expr)]
idx = 0
sym = None
return_type = Type(":any")
if token.type_ == TokenType.FUNC:
if tokens[idx].type_ != TokenType.SYMBOL:
raise ParseError("'func' must take a symbol", tokens[idx].line)
sym, counter = parseSymbol(tokens[idx], token, tokens[idx+1:])
idx += counter
else:
sym = Symbol("<lambda>", token.line)
if tokens[idx].type_ == TokenType.COLON:
return_type, counter = parseType(tokens[idx], token, tokens[idx+1:])
idx += counter
if tokens[idx].type_ != TokenType.OPEN_PAREN:
raise ParseError("expecting argument list", tokens[idx].line)
args, many, counter = parseFunctionArguments(tokens[idx:], tokens[idx-1], tokens[idx+1:])
idx += counter
body = []
while tokens[idx].type_ != TokenType.CLOSE_PAREN:
token = tokens[idx]
counter = 1
if token.type_ == TokenType.OPEN_PAREN:
expr, counter = parseExpression(token, prev, tokens[idx+1:])
body.append(expr)
elif token.type_ in (TokenType.FALSE, TokenType.TRUE, TokenType.STRING, TokenType.INT, TokenType.FLOAT):
lit, counter = parseLiteral(token, prev, tokens[idx+1:])
body.append(lit)
elif token.type_ == TokenType.COLON:
typ, counter = parseType(token, prev, tokens[idx+1:])
body.append(typ)
else:
inner_sym, counter = parseSymbol(token, prev, tokens[idx+1:])
body.append(inner_sym)
idx += counter
prev = token
return NebFuncDef(sym, return_type, args, many, body), idx + 1
def parseFunctionArguments(token, prev, tokens):
idx = 0
args = []
prev = token
many = None
prev_type = False
first = True
while tokens[idx].type_ != TokenType.CLOSE_PAREN:
token = tokens[idx]
if token.type_ == TokenType.SYMBOL:
if many is not None:
raise ParseError("& must be last argument", token.line)
sym, counter = parseSymbol(token, prev, tokens)
args.append(Arg(sym.name, TypeEnum.ANY))
prev_type = False
counter = 1
elif token.type_ == TokenType.MANY:
many = Arg("&", TypeEnum.ANY)
prev_type = False
counter = 1
elif token.type_ == TokenType.COLON and not prev_type and not first:
if prev_type:
raise ParseError("can't have two types in a row", token.line)
if first:
raise ParseError("type can't be first", token.line)
typ, counter = parseType(token, prev, tokens[idx+1:])
if many is None:
args[-1].type_ = typ
else:
many.type_ = typ
prev_type = True
else:
raise ParseError("invalid function signature", token)
first = False
idx += counter
# this should return function
return args, many, idx + 2 # parens
def parseExpression(token, prev, tokens):
idx = 0
args = []
prev = token
while tokens[idx].type_ != TokenType.CLOSE_PAREN:
token = tokens[idx]
if token.type_ == TokenType.EOF:
raise ParseError("uneven parens: not enough closing!", token.line)
inc = 1
if token.type_ == TokenType.OPEN_PAREN:
expr, inc = parseExpression(token, prev, tokens[idx+1:])
args.append(expr)
elif token.type_ in (TokenType.STRING, TokenType.TRUE, TokenType.FALSE, TokenType.INT, TokenType.FLOAT):
expr, inc = parseLiteral(token, prev, tokens[idx+1:])
args.append(expr)
elif token.type_ == TokenType.COLON:
expr, inc = parseType(token, prev, tokens[idx+1:])
args.append(expr)
elif token.type_ == TokenType.DEF:
expr, inc = parseDef(token, prev, tokens[idx+1:])
args.append(expr)
elif token.type_ in (TokenType.LAMBDA, TokenType.FUNC):
expr, inc = parseLambda(token, prev, tokens[idx+1:])
args.append(expr)
else:
expr, inc = parseSymbol(token, prev, tokens[idx+1:])
args.append(expr)
idx += inc
prev = token
return Expr(args), idx + 2 # parens
def parseSymbol(token, prev, tokens):
if token.type_ == TokenType.APOSTROPHE:
if len(tokens) == 0 or tokens[0].type_ != TokenType.SYMBOL:
raise ParseError("quote must be followed by a symbol", token.line)
return Symbol(tokens[0].text, tokens[0].line, True), 2
else:
return Symbol(token.text, token.line), 1
def parseLiteral(token, prev, tokens):
if token.type_ == TokenType.STRING:
return String(token.value), 1
elif token.type_ == TokenType.INT:
return Int(token.value), 1
elif token.type_ == TokenType.FLOAT:
return Float(token.value), 1
elif token.type_ in (TokenType.TRUE, TokenType.FALSE):
return Bool(token.value), 1
else:
return Literal(token.value), 1
def parseType(token, prev, tokens):
# if the next token is a symbol, combine for a type
if len(tokens) > 0 and tokens[0].type_ == TokenType.SYMBOL:
return Type(f":{tokens[0].text}"), 2
elif tokens[0].type_ == TokenType.OPEN_BRACKET:
# only format currently supported:
# [ <type> ]
if tokens[1].type_ != TokenType.COLON:
raise ParseError("invalid type definition (expecting colon)", tokens[1].line)
typ, counter = parseType(tokens[1], tokens[0], tokens[2:])
if tokens[1+counter].type_ != TokenType.CLOSE_BRACKET:
raise ParseError("invalid type definition (expecting close bracket)", tokens[1+counter].line)
return Type(f":[]", typ), counter + 3
elif tokens[0].type_ == TokenType.OPEN_BRACE:
# only format currently supported:
# [ <type> ]
if tokens[1].type_ != TokenType.COLON:
raise ParseError("invalid type definition (expecting colon)", tokens[1].line)
typ, counter = parseType(tokens[1], tokens[0], tokens[2:])
if tokens[1+counter].type_ != TokenType.CLOSE_BRACE:
raise ParseError("invalid type definition (expecting close brace)", tokens[1+counter].line)
return Type(":{}", typ), counter + 3
else:
raise ParseError("invalid type definition!", tokens[0].line)
def parse(tokens):
idx = 0
prev = None
exprs = []
while tokens[idx].type_ != TokenType.EOF:
token = tokens[idx]
counter = 1
if token.type_ == TokenType.CLOSE_PAREN:
raise ParseError("uneven parens: too many closing!", token.line)
elif token.type_ == TokenType.OPEN_PAREN:
expr, counter = parseExpression(token, prev, tokens[idx+1:])
exprs.append(expr)
elif token.type_ in (TokenType.FALSE, TokenType.TRUE, TokenType.STRING, TokenType.INT, TokenType.FLOAT):
lit, counter = parseLiteral(token, prev, tokens[idx+1:])
exprs.append(lit)
elif token.type_ == TokenType.COLON:
typ, counter = parseType(token, prev, tokens[idx+1:])
exprs.append(typ)
else:
sym, counter = parseSymbol(token, prev, tokens[idx+1:])
exprs.append(sym)
idx += counter
prev = token
return exprs
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