Start of highlighting multi-line comments

kilo.c

@@ -41,6 +41,7 @@ enum editorKey {
 enum editorHighlight {
 	HL_NORMAL = 0,
 	HL_COMMENT,
+	HL_MLCOMMENT,
 	HL_KEYWORD1,
 	HL_KEYWORD2,
 	HL_STRING,
@@ -53,36 +54,49 @@ enum editorHighlight {
 
 /*** data ***/
 
+/**
+ * Struct representing parsing parameters for a file type
+ */
 struct editorSyntax {
 	char *filetype;
 	char **filematch;
 	char **keywords;
 	char *singleline_comment_start;
+	char *multiline_comment_start;
+	char *multiline_comment_end;
 	int flags;
 };
 
+/**
+ * Struct representing a row in the editor
+ */
 typedef struct erow {
-	int size;
-	int rsize;
-	char *chars;
-	char *render;
-	unsigned char *hl;
+	int size; // Number of characters
+	int rsize; // Number of characters rendered to screen
+	char *chars; // Input characters
+	char *render; // Display characters
+	unsigned char *hl; // Highlighted representation of characters
 } erow;
 
+/**
+ * Global editor state
+ *
+ * // Nested comment to check for double highlight
+ */
 struct editorConfig {
-	int cx, cy;
-	int rx;
-	int rowoff;
-	int coloff;
-	int screenrows;
-	int screencols;
+	int cx, cy; // Cursor position
+	int rx;	// Cursor render position
+	int rowoff; // Vertical scroll offset
+	int coloff; // Horizontal scroll offset
+	int screenrows; // Number of rows visible in the current terminal
+	int screencols; // Number of columns visible in the current terminal
 	int numrows;
-	erow *row;
-	int dirty;
-	char *filename;
-	char statusmsg[80];
+	erow *row; // Current row
+	int dirty; // File modification check flag
+	char *filename; // Name of the current file
+	char statusmsg[80]; // Message for the status bar
 	time_t statusmsg_time;
-	struct editorSyntax *syntax;
+	struct editorSyntax *syntax; // Type of syntax for current file
 	struct termios orig_termios;
 };
 
@@ -104,7 +118,7 @@ struct editorSyntax HLDB[] = {
 		"c",
 		C_HL_extensions,
 		C_HL_keywords,
-		"//",
+		"//", "/*", "*/",
 		HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
 	},
 };
@@ -317,10 +331,16 @@ void editorUpdateSyntax(erow *row)
 	char **keywords = E.syntax->keywords;
 
 	char *scs = E.syntax->singleline_comment_start;
+	char *mcs = E.syntax->multiline_comment_start;
+	char *mce = E.syntax->multiline_comment_end;
+
 	int scs_len = scs ? strlen(scs) : 0;
+	int mcs_len = mcs ? strlen(mcs): 0;
+	int mce_len = mce ? strlen(mce): 0;
 
 	int prev_sep = 1;
 	int in_string = 0;
+	int in_comment = 0;
 
 	int i = 0;
 	while (i < row->rsize)
@@ -337,6 +357,34 @@ void editorUpdateSyntax(erow *row)
 			}
 		}
 
+		if (mcs_len && mce_len && ! in_string)
+		{
+			if (in_comment)
+			{
+				row->hl[i] = HL_MLCOMMENT;
+				if ( ! strncmp(&row->render[i], mce, mce_len))
+				{
+					memset(&row->hl[i], HL_MLCOMMENT, mce_len);
+					i += mce_len;
+					in_comment = 0;
+					prev_sep = 1;
+					continue;
+				}
+				else
+				{
+					i++;
+					continue;
+				}
+			}
+			else if ( ! strncmp(&row->render[i], mcs, mcs_len))
+			{
+				memset(&row->hl[i], HL_MLCOMMENT, mcs_len);
+				i += mcs_len;
+				in_comment = 1;
+				continue;
+			}
+		}
+
 		if (E.syntax->flags & HL_HIGHLIGHT_STRINGS)
 		{
 			if (in_string)
@@ -418,6 +466,7 @@ int editorSyntaxToColor(int hl)
 	switch (hl)
 	{
 		case HL_COMMENT:
+		case HL_MLCOMMENT:
 			return 36; // cyan
 
 		case HL_KEYWORD1: