diff options
Diffstat (limited to 'syntax/scan.go')
| -rw-r--r-- | syntax/scan.go | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/syntax/scan.go b/syntax/scan.go index 53d9f5c..a162264 100644 --- a/syntax/scan.go +++ b/syntax/scan.go @@ -182,6 +182,15 @@ var tokenNames = [...]string{ WHILE: "while", } +// A FilePortion describes the content of a portion of a file. +// Callers may provide a FilePortion for the src argument of Parse +// when the desired initial line and column numbers are not (1, 1), +// such as when an expression is parsed from within larger file. +type FilePortion struct { + Content []byte + FirstLine, FirstCol int32 +} + // A Position describes the location of a rune of input. type Position struct { file *string // filename (indirect for compactness) @@ -249,8 +258,12 @@ type scanner struct { } func newScanner(filename string, src interface{}, keepComments bool) (*scanner, error) { + var firstLine, firstCol int32 = 1, 1 + if portion, ok := src.(FilePortion); ok { + firstLine, firstCol = portion.FirstLine, portion.FirstCol + } sc := &scanner{ - pos: Position{file: &filename, Line: 1, Col: 1}, + pos: MakePosition(&filename, firstLine, firstCol), indentstk: make([]int, 1, 10), // []int{0} + spare capacity lineStart: true, keepComments: keepComments, @@ -279,6 +292,8 @@ func readSource(filename string, src interface{}) ([]byte, error) { return nil, err } return data, nil + case FilePortion: + return src.Content, nil case nil: return ioutil.ReadFile(filename) default: |