Add more comments to syntax highlighter

src/cursor.go

@@ -275,7 +275,8 @@ func (c *Cursor) GetVisualX() int {
 
 // Display draws the cursor to the screen at the correct position
 func (c *Cursor) Display() {
-	if c.y-c.v.topline < 0 || c.y-c.v.topline > c.v.height-1 {
+	// Don't draw the cursor if it is out of the viewport or if it has a selection
+	if (c.y-c.v.topline < 0 || c.y-c.v.topline > c.v.height-1) || c.HasSelection() {
 		screen.HideCursor()
 	} else {
 		screen.ShowCursor(c.GetVisualX()+c.v.lineNumOffset, c.y-c.v.topline)

src/highlighter.go

@@ -6,7 +6,6 @@ import (
 	"io/ioutil"
 	"path/filepath"
 	"regexp"
-	"strconv"
 	"strings"
 )
 
@@ -49,6 +48,178 @@ func JoinRule(rule string) string {
 	return joined
 }
 
+// LoadSyntaxFile loads the specified syntax file
+// A syntax file is a list of syntax rules, explaining how to color certain
+// regular expressions
+// Example: color comment "//.*"
+// This would color all strings that match the regex "//.*" in the comment color defined
+// by the colorscheme
+func LoadSyntaxFile(filename string) {
+	text, err := ioutil.ReadFile(filename)
+
+	if err != nil {
+		TermMessage("Error loading syntax file " + filename + ": " + err.Error())
+		return
+	}
+	lines := strings.Split(string(text), "\n")
+
+	// Regex for parsing syntax statements
+	syntaxParser := regexp.MustCompile(`syntax "(.*?)"\s+"(.*)"+`)
+	// Regex for parsing header statements
+	headerParser := regexp.MustCompile(`header "(.*)"`)
+
+	// Regex for parsing standard syntax rules
+	ruleParser := regexp.MustCompile(`color (.*?)\s+(?:\((.*?)\)\s+)?"(.*)"`)
+	// Regex for parsing syntax rules with start="..." end="..."
+	ruleStartEndParser := regexp.MustCompile(`color (.*?)\s+(?:\((.*?)\)\s+)?start="(.*)"\s+end="(.*)"`)
+
+	var syntaxRegex *regexp.Regexp
+	var headerRegex *regexp.Regexp
+	var filetype string
+	var rules []SyntaxRule
+	for lineNum, line := range lines {
+		if strings.TrimSpace(line) == "" ||
+			strings.TrimSpace(line)[0] == '#' {
+			// Ignore this line
+			continue
+		}
+
+		if strings.HasPrefix(line, "syntax") {
+			// Syntax statement
+			syntaxMatches := syntaxParser.FindSubmatch([]byte(line))
+			if len(syntaxMatches) == 3 {
+				if syntaxRegex != nil {
+					// Add the current rules to the syntaxFiles variable
+					regexes := [2]*regexp.Regexp{syntaxRegex, headerRegex}
+					syntaxFiles[regexes] = FileTypeRules{filetype, rules}
+				}
+				rules = rules[:0]
+
+				filetype = string(syntaxMatches[1])
+				extensions := JoinRule(string(syntaxMatches[2]))
+
+				syntaxRegex, err = regexp.Compile(extensions)
+				if err != nil {
+					TermError(filename, lineNum, err.Error())
+					continue
+				}
+			} else {
+				TermError(filename, lineNum, "Syntax statement is not valid: "+line)
+				continue
+			}
+		} else if strings.HasPrefix(line, "header") {
+			// Header statement
+			headerMatches := headerParser.FindSubmatch([]byte(line))
+			if len(headerMatches) == 2 {
+				header := JoinRule(string(headerMatches[1]))
+
+				headerRegex, err = regexp.Compile(header)
+				if err != nil {
+					TermError(filename, lineNum, "Regex error: "+err.Error())
+					continue
+				}
+			} else {
+				TermError(filename, lineNum, "Header statement is not valid: "+line)
+				continue
+			}
+		} else {
+			// Syntax rule, but it could be standard or start-end
+			if ruleParser.MatchString(line) {
+				// Standard syntax rule
+				// Parse the line
+				submatch := ruleParser.FindSubmatch([]byte(line))
+				var color string
+				var regexStr string
+				var flags string
+				if len(submatch) == 4 {
+					// If len is 4 then the user specified some additional flags to use
+					color = string(submatch[1])
+					flags = string(submatch[2])
+					regexStr = "(?" + flags + ")" + JoinRule(string(submatch[3]))
+				} else if len(submatch) == 3 {
+					// If len is 3, no additional flags were given
+					color = string(submatch[1])
+					regexStr = JoinRule(string(submatch[2]))
+				} else {
+					// If len is not 3 or 4 there is a problem
+					TermError(filename, lineNum, "Invalid statement: "+line)
+					continue
+				}
+				// Compile the regex
+				regex, err := regexp.Compile(regexStr)
+				if err != nil {
+					TermError(filename, lineNum, err.Error())
+					continue
+				}
+
+				// Get the style
+				// The user could give us a "color" that is really a part of the colorscheme
+				// in which case we should look that up in the colorscheme
+				// They can also just give us a straight up color
+				st := tcell.StyleDefault
+				if _, ok := colorscheme[color]; ok {
+					st = colorscheme[color]
+				} else {
+					st = StringToStyle(color)
+				}
+				// Add the regex, flags, and style
+				// False because this is not start-end
+				rules = append(rules, SyntaxRule{regex, flags, false, st})
+			} else if ruleStartEndParser.MatchString(line) {
+				// Start-end syntax rule
+				submatch := ruleStartEndParser.FindSubmatch([]byte(line))
+				var color string
+				var start string
+				var end string
+				// Use m and s flags by default
+				flags := "ms"
+				if len(submatch) == 5 {
+					// If len is 5 the user provided some additional flags
+					color = string(submatch[1])
+					flags += string(submatch[2])
+					start = string(submatch[3])
+					end = string(submatch[4])
+				} else if len(submatch) == 4 {
+					// If len is 4 the user did not provide additional flags
+					color = string(submatch[1])
+					start = string(submatch[2])
+					end = string(submatch[3])
+				} else {
+					// If len is not 4 or 5 there is a problem
+					TermError(filename, lineNum, "Invalid statement: "+line)
+					continue
+				}
+
+				// Compile the regex
+				regex, err := regexp.Compile("(?" + flags + ")" + "(" + start + ").*?(" + end + ")")
+				if err != nil {
+					TermError(filename, lineNum, err.Error())
+					continue
+				}
+
+				// Get the style
+				// The user could give us a "color" that is really a part of the colorscheme
+				// in which case we should look that up in the colorscheme
+				// They can also just give us a straight up color
+				st := tcell.StyleDefault
+				if _, ok := colorscheme[color]; ok {
+					st = colorscheme[color]
+				} else {
+					st = StringToStyle(color)
+				}
+				// Add the regex, flags, and style
+				// True because this is start-end
+				rules = append(rules, SyntaxRule{regex, flags, true, st})
+			}
+		}
+	}
+	if syntaxRegex != nil {
+		// Add the current rules to the syntaxFiles variable
+		regexes := [2]*regexp.Regexp{syntaxRegex, headerRegex}
+		syntaxFiles[regexes] = FileTypeRules{filetype, rules}
+	}
+}
+
 // LoadSyntaxFilesFromDir loads the syntax files from a specified directory
 // To load the syntax files, we must fill the `syntaxFiles` map
 // This involves finding the regex for syntax and if it exists, the regex
@@ -60,136 +231,7 @@ func LoadSyntaxFilesFromDir(dir string) {
 	files, _ := ioutil.ReadDir(dir)
 	for _, f := range files {
 		if filepath.Ext(f.Name()) == ".micro" {
-			text, err := ioutil.ReadFile(dir + "/" + f.Name())
-			filename := dir + "/" + f.Name()
-
-			if err != nil {
-				TermMessage("Error loading syntax files: " + err.Error())
-				continue
-			}
-			lines := strings.Split(string(text), "\n")
-
-			syntaxParser := regexp.MustCompile(`syntax "(.*?)"\s+"(.*)"+`)
-			headerParser := regexp.MustCompile(`header "(.*)"`)
-
-			ruleParser := regexp.MustCompile(`color (.*?)\s+(?:\((.*?)\)\s+)?"(.*)"`)
-			ruleStartEndParser := regexp.MustCompile(`color (.*?)\s+(?:\((.*?)\)\s+)?start="(.*)"\s+end="(.*)"`)
-
-			var syntaxRegex *regexp.Regexp
-			var headerRegex *regexp.Regexp
-			var filetype string
-			var rules []SyntaxRule
-			for lineNum, line := range lines {
-				if strings.TrimSpace(line) == "" ||
-					strings.TrimSpace(line)[0] == '#' {
-					// Ignore this line
-					continue
-				}
-
-				if strings.HasPrefix(line, "syntax") {
-					syntaxMatches := syntaxParser.FindSubmatch([]byte(line))
-					if len(syntaxMatches) == 3 {
-						if syntaxRegex != nil {
-							regexes := [2]*regexp.Regexp{syntaxRegex, headerRegex}
-							syntaxFiles[regexes] = FileTypeRules{filetype, rules}
-						}
-						rules = rules[:0]
-
-						filetype = string(syntaxMatches[1])
-						extensions := JoinRule(string(syntaxMatches[2]))
-
-						syntaxRegex, err = regexp.Compile(extensions)
-						if err != nil {
-							TermError(filename, lineNum, err.Error())
-							continue
-						}
-					} else {
-						TermError(filename, lineNum, "Syntax statement is not valid: "+line)
-						continue
-					}
-				} else if strings.HasPrefix(line, "header") {
-					headerMatches := headerParser.FindSubmatch([]byte(line))
-					if len(headerMatches) == 2 {
-						header := JoinRule(string(headerMatches[1]))
-
-						headerRegex, err = regexp.Compile(header)
-						if err != nil {
-							TermError(filename, lineNum, "Regex error: "+err.Error())
-							continue
-						}
-					} else {
-						TermError(filename, lineNum, "Header statement is not valid: "+line)
-						continue
-					}
-				} else {
-					if ruleParser.MatchString(line) {
-						submatch := ruleParser.FindSubmatch([]byte(line))
-						var color string
-						var regexStr string
-						var flags string
-						if len(submatch) == 4 {
-							color = string(submatch[1])
-							flags = string(submatch[2])
-							regexStr = "(?" + flags + ")" + JoinRule(string(submatch[3]))
-						} else if len(submatch) == 3 {
-							color = string(submatch[1])
-							regexStr = JoinRule(string(submatch[2]))
-						} else {
-							TermError(filename, lineNum, "Invalid statement: "+line)
-						}
-						regex, err := regexp.Compile(regexStr)
-						if err != nil {
-							TermError(filename, lineNum, err.Error())
-							continue
-						}
-
-						st := tcell.StyleDefault
-						if _, ok := colorscheme[color]; ok {
-							st = colorscheme[color]
-						} else {
-							st = StringToStyle(color)
-						}
-						rules = append(rules, SyntaxRule{regex, flags, false, st})
-					} else if ruleStartEndParser.MatchString(line) {
-						submatch := ruleStartEndParser.FindSubmatch([]byte(line))
-						var color string
-						var start string
-						var end string
-						// Use m and s flags by default
-						flags := "ms"
-						if len(submatch) == 5 {
-							color = string(submatch[1])
-							flags += string(submatch[2])
-							start = string(submatch[3])
-							end = string(submatch[4])
-						} else if len(submatch) == 4 {
-							color = string(submatch[1])
-							start = string(submatch[2])
-							end = string(submatch[3])
-						} else {
-							TermError(filename, lineNum, "Invalid statement: "+line)
-						}
-
-						regex, err := regexp.Compile("(?" + flags + ")" + "(" + start + ").*?(" + end + ")")
-						if err != nil {
-							TermError(filename, lineNum, err.Error())
-							continue
-						}
-
-						st := tcell.StyleDefault
-						if _, ok := colorscheme[color]; ok {
-							st = colorscheme[color]
-						} else {
-							st = StringToStyle(color)
-						}
-						rules = append(rules, SyntaxRule{regex, flags, true, st})
-					}
-				}
-			}
-			if syntaxRegex != nil {
-				regexes := [2]*regexp.Regexp{syntaxRegex, headerRegex}
-				syntaxFiles[regexes] = FileTypeRules{filetype, rules}
-			}
+			LoadSyntaxFile(dir + "/" + f.Name())
 		}
 	}
 }
@@ -212,6 +254,8 @@ func GetRules(buf *Buffer) ([]SyntaxRule, string) {
 type SyntaxMatches [][]tcell.Style
 
 // Match takes a buffer and returns the syntax matches a map specifying how it should be syntax highlighted
+// We need to check the start-end regexes for the entire buffer every time Match is called, but for the
+// non start-end rules, we only have to update the updateLines provided by the view
 func Match(v *View) SyntaxMatches {
 	buf := v.buf
 	rules := v.buf.rules
@@ -222,13 +266,24 @@ func Match(v *View) SyntaxMatches {
 		viewEnd = len(buf.lines)
 	}
 
+	// updateStart := v.updateLines[0]
+	// updateEnd := v.updateLines[1]
+	//
+	// if updateEnd > len(buf.lines) {
+	// 	updateEnd = len(buf.lines)
+	// }
+	// if updateStart < 0 {
+	// 	updateStart = 0
+	// }
 	lines := buf.lines[viewStart:viewEnd]
+	// updateLines := buf.lines[updateStart:updateEnd]
 	matches := make(SyntaxMatches, len(lines))
 
 	for i, line := range lines {
 		matches[i] = make([]tcell.Style, len(line))
 	}
 
+	// We don't actually check the entire buffer, just from synLinesUp to synLinesDown
 	totalStart := v.topline - synLinesUp
 	totalEnd := v.topline + v.height + synLinesDown
 	if totalStart < 0 {
@@ -249,17 +304,12 @@ func Match(v *View) SyntaxMatches {
 					value[0] += startNum
 					value[1] += startNum
 					for i := value[0]; i < value[1]; i++ {
-						colNum, lineNum := GetPos(startNum, totalStart, i, buf)
+						colNum, lineNum := FromCharPos(i, buf)
 						if lineNum == -1 || colNum == -1 {
 							continue
 						}
 						lineNum -= viewStart
 						if lineNum >= 0 && lineNum < v.height {
-							if lineNum >= len(matches) {
-								messenger.Error("Line " + strconv.Itoa(lineNum))
-							} else if colNum >= len(matches[lineNum]) {
-								messenger.Error("Line " + strconv.Itoa(lineNum) + " Col " + strconv.Itoa(colNum) + " " + strconv.Itoa(len(matches[lineNum])))
-							}
 							matches[lineNum][colNum] = rule.style
 						}
 					}
@@ -271,6 +321,7 @@ func Match(v *View) SyntaxMatches {
 					indicies := rule.regex.FindAllStringIndex(line, -1)
 					for _, value := range indicies {
 						for i := value[0]; i < value[1]; i++ {
+							// matches[lineN+updateStart][i] = rule.style
 							matches[lineN][i] = rule.style
 						}
 					}
@@ -281,20 +332,3 @@ func Match(v *View) SyntaxMatches {
 
 	return matches
 }
-
-// GetPos returns an x, y position given a character location in the buffer
-func GetPos(startLoc, startLine, loc int, buf *Buffer) (int, int) {
-	charNum := startLoc
-	x, y := 0, startLine
-
-	for i, line := range buf.lines {
-		if charNum+Count(line) > loc {
-			y = i
-			x = loc - charNum
-			return x, y
-		}
-		charNum += Count(line) + 1
-	}
-
-	return -1, -1
-}

src/view.go

@@ -110,7 +110,7 @@ func NewViewWidthHeight(buf *Buffer, w, h int) *View {
 // UpdateLines sets the values for v.updateLines
 func (v *View) UpdateLines(start, end int) {
 	v.updateLines[0] = start
-	v.updateLines[1] = end
+	v.updateLines[1] = end + 1
 }
 
 // Resize recalculates the actual width and height of the view from the width and height
@@ -352,7 +352,9 @@ func (v *View) HandleEvent(event tcell.Event) {
 			// Insert a newline
 			v.eh.Insert(v.cursor.Loc(), "\n")
 			v.cursor.Right()
-			v.UpdateLines(v.cursor.y-1, v.cursor.y)
+			// Rehighlight the entire buffer
+			v.UpdateLines(v.topline, v.topline+v.height)
+			// v.UpdateLines(v.cursor.y-1, v.cursor.y)
 		case tcell.KeySpace:
 			// Insert a space
 			v.eh.Insert(v.cursor.Loc(), " ")
@@ -377,7 +379,9 @@ func (v *View) HandleEvent(event tcell.Event) {
 				loc := v.cursor.Loc()
 				v.eh.Remove(loc-1, loc)
 				v.cursor.x, v.cursor.y = cx, cy
-				v.UpdateLines(v.cursor.y, v.cursor.y+1)
+				// Rehighlight the entire buffer
+				v.UpdateLines(v.topline, v.topline+v.height)
+				// v.UpdateLines(v.cursor.y, v.cursor.y+1)
 			}
 		case tcell.KeyTab:
 			// Insert a tab
@@ -429,10 +433,13 @@ func (v *View) HandleEvent(event tcell.Event) {
 			if v.cursor.HasSelection() {
 				v.cursor.DeleteSelection()
 				v.cursor.ResetSelection()
+				// Rehighlight the entire buffer
+				v.UpdateLines(v.topline, v.topline+v.height)
+			} else {
+				v.UpdateLines(v.cursor.y, v.cursor.y)
 			}
 			v.eh.Insert(v.cursor.Loc(), string(e.Rune()))
 			v.cursor.Right()
-			v.UpdateLines(v.cursor.y, v.cursor.y)
 		}
 	case *tcell.EventMouse:
 		x, y := e.Position()
@@ -515,11 +522,15 @@ func (v *View) HandleEvent(event tcell.Event) {
 			v.ScrollUp(2)
 			// We don't want to relocate if the user is scrolling
 			relocate = false
+			// Rehighlight the entire buffer
+			v.UpdateLines(v.topline, v.topline+v.height)
 		case tcell.WheelDown:
 			// Scroll down two lines
 			v.ScrollDown(2)
 			// We don't want to relocate if the user is scrolling
 			relocate = false
+			// Rehighlight the entire buffer
+			v.UpdateLines(v.topline, v.topline+v.height)
 		}
 	}
 
@@ -532,7 +543,18 @@ func (v *View) HandleEvent(event tcell.Event) {
 
 // DisplayView renders the view to the screen
 func (v *View) DisplayView() {
-	matches := make(SyntaxMatches, len(v.matches))
+	// matches := make(SyntaxMatches, len(v.buf.lines))
+	//
+	// viewStart := v.topline
+	// viewEnd := v.topline + v.height
+	// if viewEnd > len(v.buf.lines) {
+	// 	viewEnd = len(v.buf.lines)
+	// }
+	//
+	// lines := v.buf.lines[viewStart:viewEnd]
+	// for i, line := range lines {
+	// 	matches[i] = make([]tcell.Style, len(line))
+	// }
 
 	// The character number of the character in the top left of the screen
 	charNum := ToCharPos(0, v.topline, v.buf)
@@ -579,7 +601,14 @@ func (v *View) DisplayView() {
 		for colN, ch := range line {
 			var lineStyle tcell.Style
 			// Does the current character need to be syntax highlighted?
+
+			// if lineN >= v.updateLines[0] && lineN < v.updateLines[1] {
 			highlightStyle = v.matches[lineN][colN]
+			// } else if lineN < len(v.lastMatches) && colN < len(v.lastMatches[lineN]) {
+			// highlightStyle = v.lastMatches[lineN][colN]
+			// } else {
+			// highlightStyle = tcell.StyleDefault
+			// }
 
 			if v.cursor.HasSelection() &&
 				(charNum >= v.cursor.curSelection[0] && charNum <= v.cursor.curSelection[1] ||
@@ -593,6 +622,7 @@ func (v *View) DisplayView() {
 			} else {
 				lineStyle = highlightStyle
 			}
+			// matches[lineN][colN] = highlightStyle
 
 			if ch == '\t' {
 				screen.SetContent(x+tabchars, lineN, ' ', nil, lineStyle)
@@ -625,8 +655,7 @@ func (v *View) DisplayView() {
 
 		charNum++
 	}
-
-	v.lastMatches = matches
+	// v.lastMatches = matches
 }
 
 // Display renders the view, the cursor, and statusline

todolist.md

@@ -47,6 +47,7 @@
 
 - [x] Syntax highlighting
     - [x] Use nano-like syntax files (https://github.com/scopatz/nanorc)
+    - [ ] Optimization
 
 - [x] Undo/redo
     - [x] Undo/redo stack