diff options
Diffstat (limited to 'src/pkg/regexp/syntax/prog.go')
| -rw-r--r-- | src/pkg/regexp/syntax/prog.go | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/src/pkg/regexp/syntax/prog.go b/src/pkg/regexp/syntax/prog.go index 902d3b3a5..a482a82f2 100644 --- a/src/pkg/regexp/syntax/prog.go +++ b/src/pkg/regexp/syntax/prog.go @@ -56,23 +56,26 @@ const ( // Passing r2 == -1 indicates that the position is // at the end of the text. func EmptyOpContext(r1, r2 rune) EmptyOp { - var op EmptyOp - if r1 < 0 { - op |= EmptyBeginText | EmptyBeginLine - } - if r1 == '\n' { + var op EmptyOp = EmptyNoWordBoundary + var boundary byte + switch { + case IsWordChar(r1): + boundary = 1 + case r1 == '\n': op |= EmptyBeginLine + case r1 < 0: + op |= EmptyBeginText | EmptyBeginLine } - if r2 < 0 { - op |= EmptyEndText | EmptyEndLine - } - if r2 == '\n' { + switch { + case IsWordChar(r2): + boundary ^= 1 + case r2 == '\n': op |= EmptyEndLine + case r2 < 0: + op |= EmptyEndText | EmptyEndLine } - if IsWordChar(r1) != IsWordChar(r2) { - op |= EmptyWordBoundary - } else { - op |= EmptyNoWordBoundary + if boundary != 0 { // IsWordChar(r1) != IsWordChar(r2) + op ^= (EmptyWordBoundary | EmptyNoWordBoundary) } return op } |