added LocVoid() and Loc.IsVoid()

Author: matthias314

cmd/micro/micro.go

@@ -165,7 +165,7 @@ func LoadInput(args []string) []*buffer.Buffer {
 	}
 
 	files := make([]string, 0, len(args))
-	flagStartPos := buffer.Loc{-1, -1}
+	flagStartPos := buffer.LocVoid()
 	flagr := regexp.MustCompile(`^\+(\d+)(?::(\d+))?$`)
 	for _, a := range args {
 		match := flagr.FindStringSubmatch(a)

internal/action/command.go

@@ -971,7 +971,7 @@ func (h *BufPane) ReplaceCmd(args []string) {
 			return l.GreaterEqual(start) && l.LessEqual(end)
 		}
 
-		lastMatchEnd := buffer.Loc{-1, -1}
+		lastMatchEnd := buffer.LocVoid()
 		var doReplacement func()
 		doReplacement = func() {
 			locs := h.Buf.FindDown(rgrp, searchLoc, end)
@@ -986,7 +986,7 @@ func (h *BufPane) ReplaceCmd(args []string) {
 				// skip empty match right after previous match
 				if searchLoc == end {
 					searchLoc = start
-					lastMatchEnd = buffer.Loc{-1, -1}
+					lastMatchEnd = buffer.LocVoid()
 				} else {
 					searchLoc = searchLoc.Move(1, h.Buf)
 				}

internal/buffer/buffer.go

@@ -217,18 +217,18 @@ type Buffer struct {
 }
 
 // NewBufferFromFileAtLoc opens a new buffer with a given cursor location
-// If cursorLoc is {-1, -1} the location does not overwrite what the cursor location
+// If cursorLoc is void, the location does not overwrite what the cursor location
 // would otherwise be (start of file, or saved cursor position if `savecursor` is
 // enabled)
 func NewBufferFromFileAtLoc(path string, btype BufType, cursorLoc Loc) (*Buffer, error) {
 	var err error
 	filename := path
-	if config.GetGlobalOption("parsecursor").(bool) && cursorLoc.X == -1 && cursorLoc.Y == -1 {
+	if config.GetGlobalOption("parsecursor").(bool) && cursorLoc.IsVoid() {
 		var cursorPos []string
 		filename, cursorPos = util.GetPathAndCursorPosition(filename)
 		cursorLoc, err = ParseCursorLocation(cursorPos)
 		if err != nil {
-			cursorLoc = Loc{-1, -1}
+			cursorLoc = LocVoid()
 		}
 	}
 
@@ -280,7 +280,7 @@ func NewBufferFromFileAtLoc(path string, btype BufType, cursorLoc Loc) (*Buffer,
 // It will return an empty buffer if the path does not exist
 // and an error if the file is a directory
 func NewBufferFromFile(path string, btype BufType) (*Buffer, error) {
-	return NewBufferFromFileAtLoc(path, btype, Loc{-1, -1})
+	return NewBufferFromFileAtLoc(path, btype, LocVoid())
 }
 
 // NewBufferFromStringAtLoc creates a new buffer containing the given string with a cursor loc
@@ -290,7 +290,7 @@ func NewBufferFromStringAtLoc(text, path string, btype BufType, cursorLoc Loc) *
 
 // NewBufferFromString creates a new buffer containing the given string
 func NewBufferFromString(text, path string, btype BufType) *Buffer {
-	return NewBuffer(strings.NewReader(text), int64(len(text)), path, Loc{-1, -1}, btype)
+	return NewBuffer(strings.NewReader(text), int64(len(text)), path, LocVoid(), btype)
 }
 
 // NewBuffer creates a new buffer from a given reader with a given path

internal/buffer/loc.go

@@ -9,6 +9,16 @@ type Loc struct {
 	X, Y int
 }
 
+// LocVoid returns a Loc strictly smaller then any valid buffer location
+func LocVoid() Loc {
+	return Loc{-1, -1}
+}
+
+// IsVoid returns true if the location l is void
+func (l Loc) IsVoid() bool {
+	return l == LocVoid()
+}
+
 // LessThan returns true if b is smaller
 func (l Loc) LessThan(b Loc) bool {
 	if l.Y < b.Y {

internal/buffer/search.go

@@ -93,7 +93,7 @@ func (b *Buffer) findDownFunc(rgrp RegexpGroup, start, end Loc, find bytesFind)
 					}
 					return Loc{x, i}
 				} else { // start or end of unused submatch
-					return Loc{-1, -1}
+					return LocVoid()
 				}
 			})
 		}
@@ -113,7 +113,7 @@ func (b *Buffer) FindDown(rgrp RegexpGroup, start, end Loc) []Loc {
 // FindDownSubmatch returns a slice containing the start and end positions
 // of the first match of `rgrp` between `start` and `end` plus those
 // of all submatches (capturing groups), or nil if no match exists.
-// The start and end positions of an unused submatch are `Loc{-1, -1}`.
+// The start and end positions of an unused submatch are void.
 func (b *Buffer) FindDownSubmatch(rgrp RegexpGroup, start, end Loc) []Loc {
 	return b.findDownFunc(rgrp, start, end, (*regexp.Regexp).FindSubmatchIndex)
 }
@@ -169,7 +169,7 @@ func (b *Buffer) FindUp(rgrp RegexpGroup, start, end Loc) []Loc {
 // FindUpSubmatch returns a slice containing the start and end positions
 // of the last match of `rgrp` between `start` and `end` plus those
 // of all submatches (capturing groups), or nil if no match exists.
-// The start and end positions of an unused submatch are `Loc{-1, -1}`.
+// The start and end positions of an unused submatch are void.
 func (b *Buffer) FindUpSubmatch(rgrp RegexpGroup, start, end Loc) []Loc {
 	return b.findUpFunc(rgrp, start, end, func(re *regexp.Regexp, l []byte) []int {
 		allMatches := re.FindAllSubmatchIndex(l, -1)
@@ -259,7 +259,7 @@ func (b *Buffer) FindAllSubmatch(s string, start, end Loc) ([][]Loc, error) {
 func (b *Buffer) MatchedStrings(locs []Loc) []string {
 	strs := make([]string, len(locs)/2)
 	for i := 0; 2*i < len(locs); i += 2 {
-		if locs[2*i] != (Loc{-1, -1}) {
+		if !locs[2*i].IsVoid() {
 			strs[i] = string(b.Substr(locs[2*i], locs[2*i+1]))
 		}
 	}
@@ -310,7 +310,7 @@ func (b *Buffer) FindNext(s string, start, end, from Loc, down bool, useRegex bo
 func (b *Buffer) replaceAllFuncFunc(s string, start, end Loc, find bufferFind, repl func(match []Loc) []byte) (int, Loc, error) {
 	rgrp, err := NewRegexpGroup(s)
 	if err != nil {
-		return -1, Loc{-1, -1}, err
+		return -1, LocVoid(), err
 	}
 
 	charsEnd := util.CharacterCount(b.LineBytes(end.Y))