failing scanner

cig.h

@@ -324,6 +324,8 @@ bool scan_f32(scanner_t *s);
 bool scan_identifier(scanner_t *s);
 bool scan_string_literal(scanner_t *s);
 bool scanner_print_errors(scanner_t *s, FILE *fp);
+bool looks_like_float(scanner_t *s);
+bool looks_like_int(scanner_t *s);
 
 // string builder //////////////////////////////////////////////////////////////
 typedef struct string_builder_node {

scanner.c

@@ -332,3 +332,21 @@ bool scanner_print_errors(scanner_t *s, FILE *fp) {
 	}
 	return s->errors != NULL;
 }
+
+bool looks_like_float(scanner_t *s) {
+	const char *cur = s->cur;
+	if (*cur == '+' || *cur == '-') cur++;
+	if (!isdigit((unsigned char)*(cur++))) return false;
+	while (isdigit((unsigned char)*(cur++)));
+	if (*cur != '.') return false;
+	cur++;
+	return isdigit((unsigned char)*cur);
+}
+
+bool looks_like_int(scanner_t *s) {
+	const char *cur = s->cur;
+	if (*cur == '+' || *cur == '-') {
+		cur++;
+	}
+	return isdigit(*cur);
+}

test_arena_allocator.c

@@ -1,5 +1,4 @@
 #include <criterion/criterion.h>
-#include <criterion/internal/assert.h>
 #include <string.h>
 #include "cig.h"
 

test_scanner.c

@@ -0,0 +1,40 @@
+#include <assert.h>
+#include <criterion/criterion.h>
+#include "cig.h"
+
+Test(scanner, looks_like_float) {
+	const char *buffer =
+		"1.0 true\n"
+		"12.34 true\n"
+		"0.5 true\n"
+		"9.99 true\n"
+		"+1.2 true\n"
+		"-3.14 true\n"
+		"1 false\n"
+		"42 false\n"
+		"+7 false\n"
+		"1. false\n"
+		".5 false\n"
+		"+. false\n"
+		"abc false\n"
+		"+x false\n";
+	with_borrow(allocator) {
+		scanner_t scanner = make_scanner("test", buffer, allocator);
+		while (!scan_eof(&scanner)) {
+			bool actual = looks_like_float(&scanner);
+			while (*scanner.cur++ != ' ');
+			bool expect;
+			if (scan_literal(&scanner, "true")) {
+				expect = true;
+			} else if (scan_literal(&scanner, "false")) {
+				expect = false;
+			} else {
+				assert(false && "invalid expectation");
+			}
+			scan_whitespace(&scanner);
+			cr_assert_eq(actual, expect);
+
+		}
+	}
+
+}