commit cb0082f76c61614ad0472450d9261e2b4f2f5a8e
from: Benjamin Stürz <benni@stuerz.xyz>
date: Wed Oct 02 18:59:37 2024 UTC

irc: add float support to lexer

commit - 45eb005b00057c2d1d0b5139ff66ca73414cace4
commit + cb0082f76c61614ad0472450d9261e2b4f2f5a8e
blob - 6a547979c00fb315afb7a9582d77a179f3bf2664
blob + 06da2b1c5ba8a468173c41413ce0c9a5a83164a8
--- cc/irc/irc.c
+++ cc/irc/irc.c
@@ -10,6 +10,9 @@
 // enable debugging prints
 #define ENABLE_DEBUG 1
 
+// enable support for floating point numbers
+#define ENABLE_FLOAT 1
+
 // ERROR HANDLING
 
 int linenum;
@@ -68,6 +71,7 @@ reset (void)
 
 enum {
 	TK_INT = 128,
+	TK_FLOAT,
 	TK_REG,
 	TK_IDENT,
 	TK_STRING,
@@ -77,6 +81,7 @@ enum {
 union {
 	long i;
 	char *s;
+	double f;
 } lval;
 
 int peekd = EOF;
@@ -117,6 +122,39 @@ parse_int (void)
 
 	lval.i = i;
 	return 0;
+}
+
+parse_int_or_float (int neg)
+{
+#if ENABLE_FLOAT
+	long i = 0;
+	double f, s;
+
+	while (isdigit (peekch ()))
+		i = i * 10 + (nextch () - '0');
+
+	if (peekch () != '.') {
+		lval.i = neg ? -i : i;
+		return TK_INT;
+	}
+
+	f = i;
+	s = 0.1;
+
+	while (isdigit (peekch ())) {
+		f = f + s * (nextch () - '0');
+		s /= 10.0;
+	}
+
+	lval.f = neg ? -f : f;
+
+	return TK_FLOAT;
+#else
+	parse_int ();
+	if (neg)
+		lval.i = -lval.i;
+	return TK_INT;
+#endif
 }
 
 isname (ch)
@@ -137,8 +175,7 @@ begin:
 	ch = peekch ();
 
 	if (isdigit (ch)) {
-		parse_int ();
-		return TK_INT;
+		return parse_int_or_float (0);
 	} else if (isalpha (ch) || ch == '_') {
 		cap = 10;
 		len = 0;
@@ -162,9 +199,8 @@ begin:
 		return TK_REG;
 	case '-':
 		nextch ();
-		parse_int ();
-		lval.i = -lval.i;
-		return TK_INT;
+		return parse_int_or_float (1);
+
 	case '"':
 		nextch ();
 		cap = 10;