ScalametaParser: parse numbers with unary applied

scalameta/parsers/shared/src/main/scala/scala/meta/internal/parsers/ScalametaParser.scala

@@ -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)
@@ -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)
@@ -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)
@@ -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 =>
@@ -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
 
@@ -2910,11 +2915,10 @@ 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]) {

scalameta/trees/shared/src/main/scala/scala/meta/internal/trees/Unary.scala

@@ -0,0 +1,63 @@
+package scala.meta.internal.trees
+
+import scala.meta.tokens.Token
+
+private[meta] sealed trait Unary {
+  def op: String
+}
+
+private[meta] object Unary {
+
+  private val numericOpMap = Seq[Numeric](Plus, Minus, Tilde).map(x => x.op -> x).toMap
+  val opMap = numericOpMap ++ Seq[Unary](Not).map(x => x.op -> x)
+
+  def unapply(token: Token.Ident): Option[(String, Unary)] = {
+    val op = token.text
+    opMap.get(op).map(op -> _)
+  }
+
+  sealed trait Numeric extends Unary {
+    def apply(value: BigInt): BigInt
+    // could return None if not applicable (such as `~`)
+    def apply(value: BigDecimal): Option[BigDecimal]
+  }
+
+  object Numeric {
+    def unapply(token: Token.Ident): Option[Numeric] =
+      numericOpMap.get(token.text)
+  }
+
+  sealed trait Logical extends Unary {
+    def apply(value: Boolean): Boolean
+  }
+
+  case object Noop extends Numeric {
+    val op = ""
+    def apply(value: BigInt): BigInt = value
+    def apply(value: BigDecimal): Option[BigDecimal] = Some(value)
+  }
+
+  case object Plus extends Numeric {
+    val op = "+"
+    def apply(value: BigInt): BigInt = value
+    def apply(value: BigDecimal): Option[BigDecimal] = Some(value)
+  }
+
+  case object Minus extends Numeric {
+    val op = "-"
+    def apply(value: BigInt): BigInt = -value
+    def apply(value: BigDecimal): Option[BigDecimal] = Some(-value)
+  }
+
+  case object Tilde extends Numeric {
+    val op = "~"
+    def apply(value: BigInt): BigInt = ~value
+    def apply(value: BigDecimal): Option[BigDecimal] = None
+  }
+
+  case object Not extends Logical {
+    val op = "!"
+    def apply(value: Boolean): Boolean = !value
+  }
+
+}

scalameta/trees/shared/src/main/scala/scala/meta/internal/trees/package.scala

@@ -43,7 +43,7 @@ package object trees {
     // some heuristic is needed to govern associativity and precedence of unquoted operators
     def isLeftAssoc: Boolean = value.last != ':'
 
-    def isUnaryOp: Boolean = Set("-", "+", "~", "!").contains(value)
+    def isUnaryOp: Boolean = Unary.opMap.contains(value)
 
     def isAssignmentOp = value match {
       case "!=" | "<=" | ">=" | "" => false

tests/shared/src/test/scala/scala/meta/tests/parsers/LitSuite.scala

@@ -271,9 +271,9 @@ class LitSuite extends ParseSuite {
   }
 
   test("unary: +1") {
-    runTestAssert[Stat]("+1")(Term.ApplyUnary(tname("+"), lit(1)))
-    val tree = Term.ApplyUnary(tname("+"), Term.Apply(lit(1), List(lit(0))))
-    runTestAssert[Stat]("+1(0)")(tree)
+    runTestAssert[Stat]("+1", "1")(lit(1))
+    val tree = Term.Apply(lit(1), List(lit(0)))
+    runTestAssert[Stat]("+1(0)", "1(0)")(tree)
   }
 
   test("unary: -1") {
@@ -283,9 +283,9 @@ class LitSuite extends ParseSuite {
   }
 
   test("unary: ~1") {
-    runTestAssert[Stat]("~1")(Term.ApplyUnary(tname("~"), lit(1)))
-    val tree = Term.ApplyUnary(tname("~"), Term.Apply(lit(1), List(lit(0))))
-    runTestAssert[Stat]("~1(0)")(tree)
+    runTestAssert[Stat]("~1", "-2")(lit(-2))
+    val tree = Term.Apply(lit(-2), List(lit(0)))
+    runTestAssert[Stat]("~1(0)", "-2(0)")(tree)
   }
 
   test("unary: !1") {
@@ -295,9 +295,9 @@ class LitSuite extends ParseSuite {
   }
 
   test("unary: +1.0") {
-    runTestAssert[Stat]("+1.0", "+1.0d")(Term.ApplyUnary(tname("+"), lit(1d)))
-    val tree = Term.ApplyUnary(tname("+"), Term.Apply(lit(1d), List(lit(0))))
-    runTestAssert[Stat]("+1.0(0)", "+1.0d(0)")(tree)
+    runTestAssert[Stat]("+1.0", "1.0d")(lit(1d))
+    val tree = Term.Apply(lit(1d), List(lit(0)))
+    runTestAssert[Stat]("+1.0(0)", "1.0d(0)")(tree)
   }
 
   test("unary: -1.0") {
@@ -307,9 +307,12 @@ class LitSuite extends ParseSuite {
   }
 
   test("unary: ~1.0") {
-    runTestAssert[Stat]("~1.0", "~1.0d")(Term.ApplyUnary(tname("~"), lit(1d)))
-    val tree = Term.ApplyUnary(tname("~"), Term.Apply(lit(1d), List(lit(0))))
-    runTestAssert[Stat]("~1.0(0)", "~1.0d(0)")(tree)
+    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") {
@@ -319,15 +322,15 @@ class LitSuite extends ParseSuite {
   }
 
   test("unary: !true") {
-    runTestAssert[Stat]("!true")(Term.ApplyUnary(tname("!"), lit(true)))
-    val tree = Term.ApplyUnary(tname("!"), Term.Apply(lit(true), List(lit(0))))
-    runTestAssert[Stat]("!true(0)")(tree)
+    runTestAssert[Stat]("!true", "false")(lit(false))
+    val tree = Term.Apply(lit(false), List(lit(0)))
+    runTestAssert[Stat]("!true(0)", "false(0)")(tree)
   }
 
   test("unary: !false") {
-    runTestAssert[Stat]("!false")(Term.ApplyUnary(tname("!"), lit(false)))
-    val tree = Term.ApplyUnary(tname("!"), Term.Apply(lit(false), List(lit(0))))
-    runTestAssert[Stat]("!false(0)")(tree)
+    runTestAssert[Stat]("!false", "true")(lit(true))
+    val tree = Term.Apply(lit(true), List(lit(0)))
+    runTestAssert[Stat]("!false(0)", "true(0)")(tree)
   }
 
   test("scalatest-like infix without literal") {

tests/shared/src/test/scala/scala/meta/tests/prettyprinters/TreeSyntaxSuite.scala

@@ -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]")

tests/shared/src/test/scala/scala/meta/tests/trees/TreeSuite.scala

@@ -3,10 +3,29 @@ package trees
 
 import munit._
 import scala.meta._
+import scala.meta.internal.trees._
 
 class TreeSuite extends FunSuite {
   test("Name.unapply") {
     assert(Name.unapply(q"a").contains("a"))
     assert(Name.unapply(t"a").contains("a"))
   }
+
+  Seq(
+    ("+", Unary.Plus),
+    ("-", Unary.Minus),
+    ("~", Unary.Tilde),
+    ("!", Unary.Not)
+  ).foreach { case (op, unary) =>
+    test(s"Unary.$unary") {
+      assertEquals(unary.op, op)
+      assertEquals(Unary.opMap.get(op), Some(unary))
+      assert(op.isUnaryOp)
+    }
+  }
+
+  test(s"Unary opMap size") {
+    assertEquals(Unary.opMap.size, 4)
+  }
+
 }