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ScalametaParser: parse numbers with unary applied
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Just like we did earlier with minus for computing negative values, lets
"absorb" any unary op into the numeric or logical constants.
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@kitbellew
kitbellew committed Mar 9, 2024
1 parent 385d8ce commit 29b7c60
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Showing 3 changed files with 44 additions and 40 deletions.
56 changes: 30 additions & 26 deletions scalameta/parsers/shared/src/main/scala/scala/meta/internal/parsers/ScalametaParser.scala
View file
Expand Up @@ -544,7 +544,6 @@ class ScalametaParser(input: Input)(implicit dialect: Dialect) { parser =>
case Ident(x) => pred(x)
case _ => false
}
def isUnaryOp: Boolean = isIdentAnd(token, _.isUnaryOp)
def isIdentExcept(except: String) = isIdentAnd(token, _ != except)
def isIdentOf(tok: Token, name: String) = isIdentAnd(tok, _ == name)
@inline def isStar: Boolean = isStar(token)
Expand Down Expand Up @@ -1113,8 +1112,8 @@ class ScalametaParser(input: Input)(implicit dialect: Dialect) { parser =>
case _: Literal =>
if (dialect.allowLiteralTypes) literal()
else syntaxError(s"$dialect doesn't support literal types", at = path())
case Ident("-") if dialect.allowLiteralTypes && tryAhead[NumericConstant[_]] =>
numericLiteral(prevTokenPos, isNegated = true)
case Unary.Numeric(unary) if dialect.allowLiteralTypes && tryAhead[NumericConstant[_]] =>
numericLiteral(prevTokenPos, unary)
case _ => pathSimpleType()
}
simpleTypeRest(autoEndPosOpt(startPos)(res), startPos)
Expand Down Expand Up @@ -1332,29 +1331,30 @@ class ScalametaParser(input: Input)(implicit dialect: Dialect) { parser =>
if (acceptOpt[Dot]) selectors(name) else name
}

private def numericLiteral(startPos: Int, isNegated: Boolean): Lit = {
private def numericLiteral(startPos: Int, unary: Unary.Numeric): Lit = {
val number = token.asInstanceOf[NumericConstant[_]]
next()
autoEndPos(startPos)(numericLiteralAt(number, isNegated))
autoEndPos(startPos)(numericLiteralAt(number, unary))
}

private def numericLiteralAt(token: NumericConstant[_], isNegated: Boolean): Lit = {
private def numericLiteralAt(token: NumericConstant[_], unary: Unary.Numeric): Lit = {
def getBigInt(tok: NumericConstant[BigInt], dec: BigInt, hex: BigInt, typ: String) = {
// decimal never starts with `0` as octal was removed in 2.11; "hex" includes `0x` or `0b`
// non-decimal literals allow signed overflow within unsigned range
val max = if (tok.text(0) != '0') dec else hex
// token value is always positive as it doesn't take into account a sign
val value = tok.value
if (isNegated) {
if (value > max) syntaxError(s"integer number too small for $typ", at = token)
-value
val result = unary(value)
if (result.signum < 0) {
if (value > max) syntaxError(s"integer number too small for $typ", at = tok)
} else {
if (value >= max) syntaxError(s"integer number too large for $typ", at = token)
value
if (value >= max) syntaxError(s"integer number too large for $typ", at = tok)
}
result
}
def getBigDecimal(tok: NumericConstant[BigDecimal]) =
if (isNegated) -tok.value else tok.value
unary(tok.value)
.getOrElse(syntaxError(s"bad unary op `${unary.op}` for floating-point", at = tok))
token match {
case tok: Constant.Int =>
Lit.Int(getBigInt(tok, bigIntMaxInt, bigIntMaxUInt, "Int").intValue)
Expand All @@ -1369,7 +1369,7 @@ class ScalametaParser(input: Input)(implicit dialect: Dialect) { parser =>
}

def literal(): Lit = atCurPosNext(token match {
case number: NumericConstant[_] => numericLiteralAt(number, false)
case number: NumericConstant[_] => numericLiteralAt(number, Unary.Noop)
case Constant.Char(value) => Lit.Char(value)
case Constant.String(value) => Lit.String(value)
case t: Constant.Symbol =>
Expand Down Expand Up @@ -2228,25 +2228,30 @@ class ScalametaParser(input: Input)(implicit dialect: Dialect) { parser =>
}
}

def prefixExpr(allowRepeated: Boolean): Term =
if (!isUnaryOp) simpleExpr(allowRepeated)
else {
def prefixExpr(allowRepeated: Boolean): Term = token match {
case Unary((ident, unary)) =>
val startPos = tokenPos
val op = termName()
next()
def op = atPos(startPos)(Term.Name(ident))
def addPos(tree: Term) = autoEndPos(startPos)(tree)
def rest(tree: Term) = simpleExprRest(tree, canApply = true, startPos = startPos)
if (op.value == "-" && token.is[NumericConstant[_]])
rest(numericLiteral(startPos, isNegated = true))
else {
def otherwise =
simpleExpr0(allowRepeated = true) match {
case Success(result) => addPos(Term.ApplyUnary(op, result))
case Failure(_) =>
// maybe it is not unary operator but simply an ident `trait - {...}`
// we would fail here anyway, let's try to treat it as ident
rest(op)
}
(token, unary) match {
case (tok: NumericConstant[_], unary: Unary.Numeric) =>
next(); rest(addPos(numericLiteralAt(tok, unary)))
case (tok: BooleanConstant, unary: Unary.Logical) =>
next(); rest(addPos(Lit.Boolean(unary(tok.value))))
case _ => otherwise
}
}
case _ => simpleExpr(allowRepeated)
}

def simpleExpr(allowRepeated: Boolean): Term = simpleExpr0(allowRepeated).get

Expand Down Expand Up @@ -2913,11 +2918,10 @@ class ScalametaParser(input: Input)(implicit dialect: Dialect) { parser =>
autoEndPos(startPos)(token match {
case sidToken @ (_: Ident | _: KwThis | _: Unquote) =>
val sid = stableId()
if (token.is[NumericConstant[_]]) {
sid match {
case Term.Name("-") => return numericLiteral(startPos, isNegated = true)
case _ =>
}
(token, sidToken) match {
case (_: NumericConstant[_], Unary.Numeric(unary)) if prevTokenPos == startPos =>
return numericLiteral(startPos, unary)
case _ =>
}
val targs = if (token.is[LeftBracket]) Some(super.patternTypeArgs()) else None
if (token.is[LeftParen]) {
Expand Down
22 changes: 11 additions & 11 deletions tests/shared/src/test/scala/scala/meta/tests/parsers/LitSuite.scala
View file
Expand Up @@ -271,7 +271,7 @@ class LitSuite extends ParseSuite {
}

test("unary: +1") {
runTestAssert[Stat]("+1")(Term.ApplyUnary(tname("+"), lit(1)))
runTestAssert[Stat]("+1", "1")(lit(1))
val error =
"""|<input>:1: error: `1` does not take parameters
|+1(0)
Expand All @@ -289,7 +289,7 @@ class LitSuite extends ParseSuite {
}

test("unary: ~1") {
runTestAssert[Stat]("~1")(Term.ApplyUnary(tname("~"), lit(1)))
runTestAssert[Stat]("~1", "-2")(lit(-2))
val error =
"""|<input>:1: error: `1` does not take parameters
|~1(0)
Expand All @@ -307,7 +307,7 @@ class LitSuite extends ParseSuite {
}

test("unary: +1.0") {
runTestAssert[Stat]("+1.0", "+1.0d")(Term.ApplyUnary(tname("+"), lit(1d)))
runTestAssert[Stat]("+1.0", "1.0d")(lit(1d))
val error =
"""|<input>:1: error: `1.0` does not take parameters
|+1.0(0)
Expand All @@ -325,12 +325,12 @@ class LitSuite extends ParseSuite {
}

test("unary: ~1.0") {
runTestAssert[Stat]("~1.0", "~1.0d")(Term.ApplyUnary(tname("~"), lit(1d)))
val error =
"""|<input>:1: error: `1.0` does not take parameters
|~1.0(0)
| ^""".stripMargin
runTestError[Stat]("~1.0(0)", error)
def error(code: String) =
s"""|<input>:1: error: bad unary op `~` for floating-point
|~$code
| ^""".stripMargin
runTestError[Stat]("~1.0", error("1.0"))
runTestError[Stat]("~1.0(0)", error("1.0(0)"))
}

test("unary: !1.0") {
Expand All @@ -343,7 +343,7 @@ class LitSuite extends ParseSuite {
}

test("unary: !true") {
runTestAssert[Stat]("!true")(Term.ApplyUnary(tname("!"), lit(true)))
runTestAssert[Stat]("!true", "false")(lit(false))
val error =
"""|<input>:1: error: `true` does not take parameters
|!true(0)
Expand All @@ -352,7 +352,7 @@ class LitSuite extends ParseSuite {
}

test("unary: !false") {
runTestAssert[Stat]("!false")(Term.ApplyUnary(tname("!"), lit(false)))
runTestAssert[Stat]("!false", "true")(lit(true))
val error =
"""|<input>:1: error: `false` does not take parameters
|!false(0)
Expand Down
6 changes: 3 additions & 3 deletions tests/shared/src/test/scala/scala/meta/tests/prettyprinters/TreeSyntaxSuite.scala
View file
Expand Up @@ -76,13 +76,13 @@ class TreeSyntaxSuite extends scala.meta.tests.parsers.ParseSuite {
testBlockAddNL("Foo.bar")
testBlockAddNL("10")
testBlockAddNL("-10")
testBlockAddNL("~10")
testBlockAddNL("~10", "-11")
testBlockAddNL("10.0d")
testBlockAddNL("-10.0d")
testBlockAddNL("true")
testBlockAddNL("false")
testBlockAddNL("!true")
testBlockAddNL("!false")
testBlockAddNL("!true", "false")
testBlockAddNL("!false", "true")
testBlockNoNL("-{10}", "-{\n 10\n}")
testBlockAddNL("foo(bar)")
testBlockAddNL("foo[Bar]")
Expand Down

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