lang: lex: implement lexing of decimal numbers

lang/include/ivy/lang/lex.h

@@ -10,7 +10,8 @@ enum ivy_token_type {
 	IVY_TOK_KEYWORD,
 	IVY_TOK_SYMBOL,
 	IVY_TOK_ATOM,
-	IVY_TOK_NUMBER,
+	IVY_TOK_INT,
+	IVY_TOK_DOUBLE,
 	IVY_TOK_LABEL,
 	IVY_TOK_IDENT,
 	IVY_TOK_STRING,
@@ -104,7 +105,8 @@ struct ivy_token {
 	union {
 		enum ivy_keyword t_keyword;
 		enum ivy_symbol t_symbol;
-		unsigned long long t_number;
+		unsigned long long t_int;
+		double t_double;
 		char *t_str;
 	};
 };

lang/lex.c

@@ -537,7 +537,7 @@ static enum ivy_status push_atom(struct ivy_lexer *lex, char *s)
 	return push_token(lex, tok);
 }
 
-static enum ivy_status push_number(struct ivy_lexer *lex, unsigned long long v)
+static enum ivy_status push_int(struct ivy_lexer *lex, unsigned long long v)
 {
 	struct ivy_token *tok = malloc(sizeof *tok);
 	if (!tok) {
@@ -546,8 +546,22 @@ static enum ivy_status push_number(struct ivy_lexer *lex, unsigned long long v)
 
 	memset(tok, 0x0, sizeof *tok);
 
-	tok->t_type = IVY_TOK_NUMBER;
-	tok->t_number = v;
+	tok->t_type = IVY_TOK_INT;
+	tok->t_int = v;
+	return push_token(lex, tok);
+}
+
+static enum ivy_status push_double(struct ivy_lexer *lex, double v)
+{
+	struct ivy_token *tok = malloc(sizeof *tok);
+	if (!tok) {
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	memset(tok, 0x0, sizeof *tok);
+
+	tok->t_type = IVY_TOK_DOUBLE;
+	tok->t_double = v;
 	return push_token(lex, tok);
 }
 
@@ -784,6 +798,7 @@ static enum ivy_status read_number(struct ivy_lexer *lex)
 {
 	int token_len = 0;
 	int base = 10;
+	int dots = 0;
 	b_string *str = get_temp_string(lex);
 
 	while (true) {
@@ -802,6 +817,23 @@ static enum ivy_status read_number(struct ivy_lexer *lex)
 			continue;
 		}
 
+		if (c == '.' && iswdigit(peek_next(lex))) {
+			if (base != 10) {
+				return IVY_ERR_BAD_SYNTAX;
+			}
+
+			if (dots > 0) {
+				return IVY_ERR_BAD_SYNTAX;
+			}
+
+			token_len++;
+			dots++;
+			char s[] = {c, 0};
+			b_string_append_cstr(str, s);
+			advance(lex);
+			continue;
+		}
+
 		if (isspace(c) || ispunct(c)) {
 			break;
 		}
@@ -845,21 +877,33 @@ static enum ivy_status read_number(struct ivy_lexer *lex)
 	}
 
 	if (token_len == 1 && base == 7) {
-		return push_number(lex, 0);
+		return push_int(lex, 0);
 	}
 
 	const char *s = b_string_ptr(str);
-	char *ep;
+	char *ep = NULL;
 
 	/* negative numbers will be lexed as a hyphen followed by a positive
 	 * number. */
+
+	if (dots > 0) {
+		double v = strtod(s, &ep);
+
+		if (*ep != '\0') {
+			return IVY_ERR_BAD_SYNTAX;
+		}
+
+		return push_double(lex, v);
+
+	} else {
 		unsigned long long v = strtoull(s, &ep, base);
 
 		if (*ep != '\0') {
 			return IVY_ERR_BAD_SYNTAX;
 		}
 
-	return push_number(lex, v);
+		return push_int(lex, v);
+	}
 }
 
 static enum ivy_status read_ident(struct ivy_lexer *lex)
@@ -1028,7 +1072,8 @@ const char *ivy_lex_token_type_to_string(enum ivy_token_type type)
 		ENUM_STR(IVY_TOK_KEYWORD);
 		ENUM_STR(IVY_TOK_SYMBOL);
 		ENUM_STR(IVY_TOK_ATOM);
-		ENUM_STR(IVY_TOK_NUMBER);
+		ENUM_STR(IVY_TOK_INT);
+		ENUM_STR(IVY_TOK_DOUBLE);
 		ENUM_STR(IVY_TOK_LABEL);
 		ENUM_STR(IVY_TOK_IDENT);
 		ENUM_STR(IVY_TOK_STRING);