From d2a7328b09499a4d1dc2ef3dac9e69d877c83540 Mon Sep 17 00:00:00 2001
From: Ben Harris <ben@tilde.team>
Date: Mon, 5 Aug 2019 12:02:39 -0400
Subject: [PATCH] highlight keywords

---
 kilo.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/kilo.c b/kilo.c
index c1e6539..141f41e 100644
--- a/kilo.c
+++ b/kilo.c
@@ -38,6 +38,9 @@ enum editorKey {
 
 enum editorHighlight {
     HL_NORMAL = 0,
+    HL_COMMENT,
+    HL_KEYWORD1,
+    HL_KEYWORD2,
     HL_STRING,
     HL_NUMBER,
     HL_MATCH
@@ -51,6 +54,8 @@ enum editorHighlight {
 struct editorSyntax {
     char *filetype;
     char **filematch;
+    char **keywords;
+    char *singleline_comment_start;
     int flags;
 };
 
@@ -84,11 +89,19 @@ struct editorConfig E;
 /*** filetypes ***/
 
 char *C_HL_extensions[] = { ".c", ".h", ".cpp", NULL };
+char *C_HL_keywords[] = {
+    "switch", "if", "while", "for", "break", "continue", "return", "else",
+    "struct", "union", "typedef", "static", "enum", "class", "case",
+    "int|", "long|", "double|", "float|", "char|" , "unsigned|", "signed|",
+    "void|", NULL
+};
 
 struct editorSyntax HLDB[] = {
     {
         "c",
         C_HL_extensions,
+        C_HL_keywords,
+        "//",
         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
     },
 };
@@ -243,6 +256,11 @@ void editorUpdateSyntax(erow *row) {
     if (E.syntax == NULL)
         return;
 
+    char **keywords = E.syntax->keywords;
+
+    char *scs = E.syntax->singleline_comment_start;
+    int scs_len = scs ? strlen(scs) : 0;
+
     int prev_sep = 1;
     int in_string = 0;
 
@@ -251,6 +269,13 @@ void editorUpdateSyntax(erow *row) {
         char c = row->render[i];
         unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;
 
+        if (scs_len && !in_string) {
+            if (!strncmp(&row->render[i], scs, scs_len)) {
+                memset(&row->hl[i], HL_COMMENT, row->rsize - 1);
+                break;
+            }
+        }
+
         if (E.syntax->flags & HL_HIGHLIGHT_STRINGS) {
             if (in_string) {
                 row->hl[i] = HL_STRING;
@@ -284,6 +309,26 @@ void editorUpdateSyntax(erow *row) {
             }
         }
 
+        if (prev_sep) {
+            int j;
+            for (j = 0; keywords[j]; j++) {
+                int klen = strlen(keywords[j]);
+                int kw2 = keywords[j][klen - 1] == '|';
+                if (kw2) klen--;
+
+                if (!strncmp(&row->render[i], keywords[j], klen) &&
+                        is_separator(row->render[i + klen])) {
+                    memset(&row->hl[i], kw2 ? HL_KEYWORD2 : HL_KEYWORD1, klen);
+                    i += klen;
+                    break;
+                }
+            }
+            if (keywords[j] != NULL) {
+                prev_sep = 0;
+                continue;
+            }
+        }
+
         prev_sep = is_separator(c);
         i++;
     }
@@ -291,6 +336,9 @@ void editorUpdateSyntax(erow *row) {
 
 int editorSyntaxToColor(int hl) {
     switch (hl) {
+        case HL_COMMENT: return 36;
+        case HL_KEYWORD1: return 33;
+        case HL_KEYWORD2: return 32;
         case HL_STRING: return 35;
         case HL_NUMBER: return 31;
         case HL_NORMAL: return 34;