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SPEC change: ^ is right-assoc and of highest priority

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Araq 2011-01-10 21:28:48 +01:00
commit 19fbc8a55e
4 changed files with 38 additions and 26 deletions
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43
rod/pnimsyn.nim
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@ -1,7 +1,7 @@
#
#
# The Nimrod Compiler
# (c) Copyright 2009 Andreas Rumpf
# (c) Copyright 2011 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
@ -145,11 +145,14 @@ proc parseStmt(p: var TParser): PNode
proc parseTypeDesc(p: var TParser): PNode
proc parseParamList(p: var TParser): PNode
proc IsLeftAssociative(tok: PToken): bool {.inline.} =
result = tok.tokType != tkOpr or tok.ident.s[0] != '^'
proc getPrecedence(tok: PToken): int =
case tok.tokType
of tkOpr:
case tok.ident.s[0]
of '$': result = 7
of '$', '^': result = 7
of '*', '%', '/', '\\': result = 6
of '+', '-', '~', '|': result = 5
of '&': result = 4
@ -159,7 +162,7 @@ proc getPrecedence(tok: PToken): int =
of tkIn, tkNotIn, tkIs, tkIsNot: result = 3
of tkAnd: result = 2
of tkOr, tkXor: result = 1
else: result = - 1
else: result = - 10
proc isOperator(tok: PToken): bool =
result = getPrecedence(tok) >= 0
@ -386,14 +389,10 @@ proc parseAddr(p: var TParser): PNode =
proc setBaseFlags(n: PNode, base: TNumericalBase) =
case base
of base10:
nil
of base2:
incl(n.flags, nfBase2)
of base8:
incl(n.flags, nfBase8)
of base16:
incl(n.flags, nfBase16)
of base10: nil
of base2: incl(n.flags, nfBase2)
of base8: incl(n.flags, nfBase8)
of base16: incl(n.flags, nfBase16)
proc identOrLiteral(p: var TParser): PNode =
case p.tok.tokType
@ -475,7 +474,7 @@ proc identOrLiteral(p: var TParser): PNode =
result = parseAddr(p)
else:
parMessage(p, errExprExpected, tokToStr(p.tok))
getTok(p) # we must consume a token here to prevend endless loops!
getTok(p) # we must consume a token here to prevend endless loops!
result = nil
proc primary(p: var TParser): PNode =
@ -520,25 +519,23 @@ proc primary(p: var TParser): PNode =
else: break
proc lowestExprAux(p: var TParser, v: var PNode, limit: int): PToken =
var
op, nextop: PToken
opPred: int
v2, node, opNode: PNode
v = primary(p) # expand while operators have priorities higher than 'limit'
op = p.tok
opPred = getPrecedence(p.tok)
while (opPred > limit):
node = newNodeP(nkInfix, p)
opNode = newIdentNodeP(op.ident, p) # skip operator:
var op = p.tok
var opPrec = getPrecedence(op)
while opPrec >= limit:
var leftAssoc = ord(IsLeftAssociative(op))
var node = newNodeP(nkInfix, p)
var opNode = newIdentNodeP(op.ident, p) # skip operator:
getTok(p)
optInd(p, opNode) # read sub-expression with higher priority
nextop = lowestExprAux(p, v2, opPred)
var v2: PNode
var nextop = lowestExprAux(p, v2, opPrec + leftAssoc)
addSon(node, opNode)
addSon(node, v)
addSon(node, v2)
v = node
op = nextop
opPred = getPrecedence(nextop)
opPrec = getPrecedence(nextop)
result = op # return first untreated operator
proc lowestExpr(p: var TParser): PNode =