matterbridge/vendor/github.com/d5/tengo/compiler/source/file.go

111 lines
2.3 KiB
Go

package source
// File represents a source file.
type File struct {
// File set for the file
set *FileSet
// File name as provided to AddFile
Name string
// Pos value range for this file is [base...base+size]
Base int
// File size as provided to AddFile
Size int
// Lines contains the offset of the first character for each line (the first entry is always 0)
Lines []int
}
// Set returns FileSet.
func (f *File) Set() *FileSet {
return f.set
}
// LineCount returns the current number of lines.
func (f *File) LineCount() int {
return len(f.Lines)
}
// AddLine adds a new line.
func (f *File) AddLine(offset int) {
if i := len(f.Lines); (i == 0 || f.Lines[i-1] < offset) && offset < f.Size {
f.Lines = append(f.Lines, offset)
}
}
// LineStart returns the position of the first character in the line.
func (f *File) LineStart(line int) Pos {
if line < 1 {
panic("illegal line number (line numbering starts at 1)")
}
if line > len(f.Lines) {
panic("illegal line number")
}
return Pos(f.Base + f.Lines[line-1])
}
// FileSetPos returns the position in the file set.
func (f *File) FileSetPos(offset int) Pos {
if offset > f.Size {
panic("illegal file offset")
}
return Pos(f.Base + offset)
}
// Offset translates the file set position into the file offset.
func (f *File) Offset(p Pos) int {
if int(p) < f.Base || int(p) > f.Base+f.Size {
panic("illegal Pos value")
}
return int(p) - f.Base
}
// Position translates the file set position into the file position.
func (f *File) Position(p Pos) (pos FilePos) {
if p != NoPos {
if int(p) < f.Base || int(p) > f.Base+f.Size {
panic("illegal Pos value")
}
pos = f.position(p)
}
return
}
func (f *File) position(p Pos) (pos FilePos) {
offset := int(p) - f.Base
pos.Offset = offset
pos.Filename, pos.Line, pos.Column = f.unpack(offset)
return
}
func (f *File) unpack(offset int) (filename string, line, column int) {
filename = f.Name
if i := searchInts(f.Lines, offset); i >= 0 {
line, column = i+1, offset-f.Lines[i]+1
}
return
}
func searchInts(a []int, x int) int {
// This function body is a manually inlined version of:
// return sort.Search(len(a), func(i int) bool { return a[i] > x }) - 1
i, j := 0, len(a)
for i < j {
h := i + (j-i)/2 // avoid overflow when computing h
// i ≤ h < j
if a[h] <= x {
i = h + 1
} else {
j = h
}
}
return i - 1
}