lex keywords

4 files changed, 34 insertions, 2 deletions

diff --git a/lexer.c b/lexer.c
index 803949e..a3394be 100644
--- a/lexer.c
+++ b/lexer.c
@@ -76,11 +76,27 @@ lexer(Slice slice)
 			continue;
 		}
 
-		// Word token.
+		// Word token, and keywords by extension.
 		if (iswordy(slice.str[i])) {
 			Slice word = slice_match(slice_sub(slice, i, slice.end),
 			                         iswordy);
-			token_append(&toks, token_create(word, TOK_NUMBER));
+
+			// Keywords.
+			unsigned int type = TOK_WORD;
+			if (slice_equal(word, slice_from_str("while")))
+				type = TOK_KW_WHILE;
+			else if (slice_equal(word, slice_from_str("if")))
+				type = TOK_KW_IF;
+			else if (slice_equal(word, slice_from_str("else")))
+				type = TOK_KW_ELSE;
+			else if (slice_equal(word, slice_from_str("local")))
+				type = TOK_KW_LOCAL;
+			else if (slice_equal(word, slice_from_str("return")))
+				type = TOK_KW_RETURN;
+			else if (slice_equal(word, slice_from_str("global")))
+				type = TOK_KW_GLOBAL;
+
+			token_append(&toks, token_create(word, type));
 			i = word.end;
 			continue;
 		}
diff --git a/slice.c b/slice.c
index 8640d0f..f658124 100644
--- a/slice.c
+++ b/slice.c
@@ -26,3 +26,12 @@ slice_sub(Slice src, int begin, int end)
 {
 	return (Slice){ src.str, begin, end };
 }
+
+int
+slice_equal(Slice s0, Slice s1)
+{
+	if (s0.end - s0.begin != s1.end - s1.begin)
+		return 0;
+	return 0 ==
+	       strncmp(s0.str + s0.begin, s1.str + s1.begin, s0.end - s0.begin);
+}
diff --git a/slice.h b/slice.h
index 9669132..aa4ed4d 100644
--- a/slice.h
+++ b/slice.h
@@ -9,3 +9,4 @@ typedef struct {
 Slice slice_print(Slice slice);
 Slice slice_from_str(char *str);
 Slice slice_sub(Slice src, int begin, int end);
+int slice_equal(Slice s0, Slice s1);
diff --git a/token.h b/token.h
index 9c6de47..5934f7b 100644
--- a/token.h
+++ b/token.h
@@ -15,6 +15,12 @@ enum {
 	TOK_CHARACTER  = 'a',
 	TOK_STRING     = 's',
 	TOK_WORD       = 'w',
+	TOK_KW_LOCAL   = 'L',
+	TOK_KW_GLOBAL  = 'G',
+	TOK_KW_IF      = 'I',
+	TOK_KW_ELSE    = 'E',
+	TOK_KW_WHILE   = 'W',
+	TOK_KW_RETURN  = 'R',
 };
 
 typedef struct Token Token;