From 9d925a30c73ee5856c83d3caab124f7dbeaa85a8 Mon Sep 17 00:00:00 2001 From: Som Snytt Date: Sun, 22 Apr 2012 02:58:26 -0700 Subject: SI-5702 Pattern parser halts on star In patterns, the parser halts when it sees stars. This means it does not handle infix notation for a case class named "*". This patch uses lookahead to decide whether to parse '_' '*' as a sequence pattern or as the start of infix. (For both normal and error cases, the tokens are always consumed immediately.) Error messages are improved for _* (as a help to learners) and slightly improved recovery helps the parse continue. The entry point for XML patterns is now distinct; otherwise, the change is local to pattern3-simplepattern; the entry point for simplepattern() is unchanged because it is commented "hook for IDE." --- test/files/neg/t1878-typer.check | 4 ++++ test/files/neg/t1878-typer.scala | 6 ++++++ test/files/neg/t1878.check | 24 +++++----------------- test/files/neg/t1878.scala | 2 ++ test/files/neg/t3189.check | 4 ++++ test/files/neg/t3189.scala | 3 +++ test/files/neg/t5702-neg-bad-and-wild.check | 28 ++++++++++++++++++++++++++ test/files/neg/t5702-neg-bad-and-wild.scala | 29 +++++++++++++++++++++++++++ test/files/neg/t5702-neg-bad-brace.check | 10 ++++++++++ test/files/neg/t5702-neg-bad-brace.scala | 17 ++++++++++++++++ test/files/neg/t5702-neg-bad-xbrace.check | 7 +++++++ test/files/neg/t5702-neg-bad-xbrace.scala | 31 +++++++++++++++++++++++++++++ test/files/neg/t5702-neg-ugly-xbrace.check | 19 ++++++++++++++++++ test/files/neg/t5702-neg-ugly-xbrace.scala | 14 +++++++++++++ test/files/pos/t5702-pos-infix-star.scala | 15 ++++++++++++++ 15 files changed, 194 insertions(+), 19 deletions(-) create mode 100644 test/files/neg/t1878-typer.check create mode 100644 test/files/neg/t1878-typer.scala create mode 100644 test/files/neg/t3189.check create mode 100644 test/files/neg/t3189.scala create mode 100644 test/files/neg/t5702-neg-bad-and-wild.check create mode 100644 test/files/neg/t5702-neg-bad-and-wild.scala create mode 100644 test/files/neg/t5702-neg-bad-brace.check create mode 100644 test/files/neg/t5702-neg-bad-brace.scala create mode 100644 test/files/neg/t5702-neg-bad-xbrace.check create mode 100644 test/files/neg/t5702-neg-bad-xbrace.scala create mode 100644 test/files/neg/t5702-neg-ugly-xbrace.check create mode 100644 test/files/neg/t5702-neg-ugly-xbrace.scala create mode 100644 test/files/pos/t5702-pos-infix-star.scala (limited to 'test/files') diff --git a/test/files/neg/t1878-typer.check b/test/files/neg/t1878-typer.check new file mode 100644 index 0000000000..e3a20d0be7 --- /dev/null +++ b/test/files/neg/t1878-typer.check @@ -0,0 +1,4 @@ +t1878-typer.scala:4: error: _* may only come last + case

{ _* }

=> + ^ +one error found diff --git a/test/files/neg/t1878-typer.scala b/test/files/neg/t1878-typer.scala new file mode 100644 index 0000000000..1eb0cb7dff --- /dev/null +++ b/test/files/neg/t1878-typer.scala @@ -0,0 +1,6 @@ +object Test extends App { + // illegal - bug #1764 + null match { + case

{ _* }

=> + } +} diff --git a/test/files/neg/t1878.check b/test/files/neg/t1878.check index b47367e12c..ac2071c3d8 100644 --- a/test/files/neg/t1878.check +++ b/test/files/neg/t1878.check @@ -1,21 +1,7 @@ -t1878.scala:3: error: _* may only come last +t1878.scala:3: error: bad use of _* (a sequence pattern must be the last pattern) val err1 = "" match { case Seq(f @ _*, ',') => f } - ^ -t1878.scala:3: error: scrutinee is incompatible with pattern type; - found : Seq[A] - required: String - val err1 = "" match { case Seq(f @ _*, ',') => f } - ^ -t1878.scala:3: error: not found: value f - val err1 = "" match { case Seq(f @ _*, ',') => f } - ^ -t1878.scala:3: error: value _2 is not a member of object Seq - val err1 = "" match { case Seq(f @ _*, ',') => f } - ^ -t1878.scala:9: error: _* may only come last + ^ +t1878.scala:9: error: bad use of _* (a sequence pattern must be the last pattern) val List(List(_*, arg2), _) = List(List(1,2,3), List(4,5,6)) - ^ -t1878.scala:13: error: _* may only come last - case

{ _* }

=> - ^ -6 errors found + ^ +two errors found diff --git a/test/files/neg/t1878.scala b/test/files/neg/t1878.scala index 5278fbb7bd..99fee48a96 100644 --- a/test/files/neg/t1878.scala +++ b/test/files/neg/t1878.scala @@ -8,8 +8,10 @@ object Test extends App { // illegal val List(List(_*, arg2), _) = List(List(1,2,3), List(4,5,6)) + /* see t1878-typer.scala // illegal - bug #1764 null match { case

{ _* }

=> } + */ } diff --git a/test/files/neg/t3189.check b/test/files/neg/t3189.check new file mode 100644 index 0000000000..3913c526a2 --- /dev/null +++ b/test/files/neg/t3189.check @@ -0,0 +1,4 @@ +t3189.scala:2: error: use _* to match a sequence + val Array(a,b*) = ("": Any) + ^ +one error found diff --git a/test/files/neg/t3189.scala b/test/files/neg/t3189.scala new file mode 100644 index 0000000000..4ea4bb7581 --- /dev/null +++ b/test/files/neg/t3189.scala @@ -0,0 +1,3 @@ +object A { + val Array(a,b*) = ("": Any) +} \ No newline at end of file diff --git a/test/files/neg/t5702-neg-bad-and-wild.check b/test/files/neg/t5702-neg-bad-and-wild.check new file mode 100644 index 0000000000..eae81ad5f2 --- /dev/null +++ b/test/files/neg/t5702-neg-bad-and-wild.check @@ -0,0 +1,28 @@ +t5702-neg-bad-and-wild.scala:10: error: bad use of _* (a sequence pattern must be the last pattern) + case List(1, _*,) => // bad use of _* (a sequence pattern must be the last pattern) + ^ +t5702-neg-bad-and-wild.scala:10: error: illegal start of simple pattern + case List(1, _*,) => // bad use of _* (a sequence pattern must be the last pattern) + ^ +t5702-neg-bad-and-wild.scala:12: error: illegal start of simple pattern + case List(1, _*3,) => // illegal start of simple pattern + ^ +t5702-neg-bad-and-wild.scala:14: error: use _* to match a sequence + case List(1, x*) => // use _* to match a sequence + ^ +t5702-neg-bad-and-wild.scala:15: error: trailing * is not a valid pattern + case List(x*, 1) => // trailing * is not a valid pattern + ^ +t5702-neg-bad-and-wild.scala:16: error: trailing * is not a valid pattern + case (1, x*) => // trailing * is not a valid pattern + ^ +t5702-neg-bad-and-wild.scala:17: error: bad use of _* (sequence pattern not allowed) + case (1, x@_*) => // bad use of _* (sequence pattern not allowed) + ^ +t5702-neg-bad-and-wild.scala:23: error: bad use of _* (a sequence pattern must be the last pattern) + val K(ns @ _*, x) = k // bad use of _* (a sequence pattern must be the last pattern) + ^ +t5702-neg-bad-and-wild.scala:24: error: bad use of _* (sequence pattern not allowed) + val (b, _ * ) = Pair(5,6) // bad use of _* (sequence pattern not allowed) + ^ +9 errors found diff --git a/test/files/neg/t5702-neg-bad-and-wild.scala b/test/files/neg/t5702-neg-bad-and-wild.scala new file mode 100644 index 0000000000..3833a002b1 --- /dev/null +++ b/test/files/neg/t5702-neg-bad-and-wild.scala @@ -0,0 +1,29 @@ + +object Test { + case class K(i: Int) + + def main(args: Array[String]) { + val k = new K(9) + val is = List(1,2,3) + + is match { + case List(1, _*,) => // bad use of _* (a sequence pattern must be the last pattern) + // illegal start of simple pattern + case List(1, _*3,) => // illegal start of simple pattern + //case List(1, _*3:) => // poor recovery by parens + case List(1, x*) => // use _* to match a sequence + case List(x*, 1) => // trailing * is not a valid pattern + case (1, x*) => // trailing * is not a valid pattern + case (1, x@_*) => // bad use of _* (sequence pattern not allowed) + } + +// good syntax, bad semantics, detected by typer +//gowild.scala:14: error: star patterns must correspond with varargs parameters + val K(is @ _*) = k + val K(ns @ _*, x) = k // bad use of _* (a sequence pattern must be the last pattern) + val (b, _ * ) = Pair(5,6) // bad use of _* (sequence pattern not allowed) +// no longer complains +//bad-and-wild.scala:15: error: ')' expected but '}' found. + } +} + diff --git a/test/files/neg/t5702-neg-bad-brace.check b/test/files/neg/t5702-neg-bad-brace.check new file mode 100644 index 0000000000..503f7d95ed --- /dev/null +++ b/test/files/neg/t5702-neg-bad-brace.check @@ -0,0 +1,10 @@ +t5702-neg-bad-brace.scala:14: error: Unmatched closing brace '}' ignored here + case List(1, _*} => + ^ +t5702-neg-bad-brace.scala:14: error: illegal start of simple pattern + case List(1, _*} => + ^ +t5702-neg-bad-brace.scala:15: error: ')' expected but '}' found. + } + ^ +three errors found diff --git a/test/files/neg/t5702-neg-bad-brace.scala b/test/files/neg/t5702-neg-bad-brace.scala new file mode 100644 index 0000000000..16a341cf8c --- /dev/null +++ b/test/files/neg/t5702-neg-bad-brace.scala @@ -0,0 +1,17 @@ + +object Test { + + def main(args: Array[String]) { + val is = List(1,2,3) + + is match { +// the erroneous brace is ignored, so we can't halt on it. +// maybe brace healing can detect overlapping unmatched (...} +// In this case, the fix emits an extra error: +// t5702-neg-bad-brace.scala:10: error: Unmatched closing brace '}' ignored here +// t5702-neg-bad-brace.scala:10: error: illegal start of simple pattern (i.e., =>) +// t5702-neg-bad-brace.scala:11: error: ')' expected but '}' found. + case List(1, _*} => + } + } +} diff --git a/test/files/neg/t5702-neg-bad-xbrace.check b/test/files/neg/t5702-neg-bad-xbrace.check new file mode 100644 index 0000000000..d88638aee9 --- /dev/null +++ b/test/files/neg/t5702-neg-bad-xbrace.check @@ -0,0 +1,7 @@ +t5702-neg-bad-xbrace.scala:19: error: bad brace or paren after _* + case {_*)} => y + ^ +t5702-neg-bad-xbrace.scala:28: error: bad brace or paren after _* + val {a, z@_*)} = xml + ^ +two errors found diff --git a/test/files/neg/t5702-neg-bad-xbrace.scala b/test/files/neg/t5702-neg-bad-xbrace.scala new file mode 100644 index 0000000000..64bbdb18be --- /dev/null +++ b/test/files/neg/t5702-neg-bad-xbrace.scala @@ -0,0 +1,31 @@ + +object Test { + def main(args: Array[String]) { + /* PiS example, minus a brace + val yearMade = 1965 + val old = + { if (yearMade < 2000) yearMade} + else xml.NodeSeq.Empty } + println(old) + */ + + // bad brace or paren after _* + // actually, we know it's a bad paren... + // we skip it because not in a context looking for rparen + val xyear = 1965 + val ancient = + { + val when = xyear match { + case {_*)} => y + case _ => "2035" + } + {when} + } + println(ancient) + + val xml = appleboychild + // bad brace or paren after _* + val {a, z@_*)} = xml + println("A for "+ a +", ending with "+ z) + } +} diff --git a/test/files/neg/t5702-neg-ugly-xbrace.check b/test/files/neg/t5702-neg-ugly-xbrace.check new file mode 100644 index 0000000000..7d80bbf6be --- /dev/null +++ b/test/files/neg/t5702-neg-ugly-xbrace.check @@ -0,0 +1,19 @@ +t5702-neg-ugly-xbrace.scala:11: error: bad brace or paren after _* + val {a, z@_*) = xml + ^ +t5702-neg-ugly-xbrace.scala:12: error: Missing closing brace `}' assumed here + println("A for "+ a +", ending with "+ z) + ^ +t5702-neg-ugly-xbrace.scala:13: error: in XML literal: in XML content, please use '}}' to express '}' + } + ^ +t5702-neg-ugly-xbrace.scala:11: error: I encountered a '}' where I didn't expect one, maybe this tag isn't closed + val {a, z@_*) = xml + ^ +t5702-neg-ugly-xbrace.scala:14: error: illegal start of simple pattern +} +^ +t5702-neg-ugly-xbrace.scala:14: error: '}' expected but eof found. +} + ^ +6 errors found diff --git a/test/files/neg/t5702-neg-ugly-xbrace.scala b/test/files/neg/t5702-neg-ugly-xbrace.scala new file mode 100644 index 0000000000..0ff7bfa09d --- /dev/null +++ b/test/files/neg/t5702-neg-ugly-xbrace.scala @@ -0,0 +1,14 @@ + +object Test { + def main(args: Array[String]) { + + val xml = appleboychild + // This is the more likely typo, and the uglier parse. + // We could turn it into a } if } does not follow (to + // avoid handing }} back to xml) but that is quite ad hoc. + // Assuming } for ) after _* would not be not outlandish. + // bad brace or paren after _* + val {a, z@_*) = xml + println("A for "+ a +", ending with "+ z) + } +} diff --git a/test/files/pos/t5702-pos-infix-star.scala b/test/files/pos/t5702-pos-infix-star.scala new file mode 100644 index 0000000000..756bcdd8de --- /dev/null +++ b/test/files/pos/t5702-pos-infix-star.scala @@ -0,0 +1,15 @@ + +object Test { + case class *(a: Int, b: Int) + type Star = * + case class P(a: Int, b: Star) // alias still required + + def main(args: Array[String]) { + val v = new *(6,7) + val x * y = v + printf("%d,%d\n",x,y) + val p = P(5, v) + val P(a, b * c) = p + printf("%d,%d,%d\n",a,b,c) + } +} -- cgit v1.2.3