Fix integer parsing

3 files changed, 37 insertions, 12 deletions

diff --git a/src/lexer.c b/src/lexer.c
index adfe8d3..5d9c5e7 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -1,6 +1,7 @@
 #include <lcq/pit/utils.h>
 #include <lcq/pit/lexer.h>
 #include <lcq/pit/types.h>
+#include <stdio.h>
 
 const char *PIT_LEX_TOKEN_NAMES[PIT_LEX_TOKEN__SENTINEL] = {
     /* [PIT_LEX_TOKEN_EOF] = */ "eof",
@@ -92,20 +93,34 @@ restart:
         }
         advance(st);
         return PIT_LEX_TOKEN_STRING_LITERAL;
-    default:
+    default: {
         if (pit_ctype_isspace(c)) goto restart;
-        if (pit_ctype_isdigit(c)) {
-            if (c == '0') {
-                int next = peek(st);
-                if (next != 'x' && next != 'o' && next != 'b') return PIT_LEX_TOKEN_INTEGER_LITERAL;
-                advance(st); /* skip base specifier */
-            }
-            while (match(st, is_hexdigit)) {}
-            return PIT_LEX_TOKEN_INTEGER_LITERAL;
+        pit_lex_token ret = PIT_LEX_TOKEN_INTEGER_LITERAL;
+        int num_idx = 0;
+        bool leading_dash = false;
+        bool zero_prefix = false;
+        if (!is_symchar(c)) {
+            st->error = "unknown character";
+            return PIT_LEX_TOKEN_ERROR;
         } else {
-            while (match(st, is_symchar)) {}
-            return PIT_LEX_TOKEN_SYMBOL;
+            do {
+                leading_dash = false;
+                switch (num_idx) {
+                case 0:
+                    if (c == '0') zero_prefix = true;
+                    else if (c == '-') { leading_dash = true; continue; }
+                    break;
+                case 1:
+                    if (zero_prefix && (c == 'x' || c == 'o' || c == 'b')) continue;
+                    break;
+                }
+                if (!is_hexdigit(c)) ret = PIT_LEX_TOKEN_SYMBOL;
+                ++num_idx;
+            } while (c = peek(st), match(st, is_symchar));
         }
+        if (leading_dash) return PIT_LEX_TOKEN_SYMBOL;
+        return ret;
+    }
     }
 }
 
diff --git a/src/parser.c b/src/parser.c
index 5dc57db..77b4172 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -129,7 +129,16 @@ pit_value pit_parse(pit_runtime *rt, pit_parser *st, bool *eof) {
         i64 idx = st->cur.start;
         i64 base = 10;
         i64 total = 0;
+        bool neg = false;
         char c = st->lexer->input[idx++];
+        if (c == '-') {
+            neg = true;
+            if (idx < st->cur.end) {
+                c = st->lexer->input[idx++];
+            } else {
+                pit_error(rt, "malformed negative integer literal"); return PIT_NIL;
+            }
+        }
         if (c == '0' && idx + 1 < st->cur.end) {
             switch (st->lexer->input[idx++]) {
             case 'b': base = 2; break;
@@ -145,7 +154,7 @@ pit_value pit_parse(pit_runtime *rt, pit_parser *st, bool *eof) {
                 pit_error(rt, "integer literal too large"); return PIT_NIL;
             }
         }
-        return pit_integer_new(rt, total);
+        return pit_integer_new(rt, neg ? -total : total);
     }
     case PIT_LEX_TOKEN_STRING_LITERAL: {
         char buf[256] = {0};
diff --git a/src/utils.c b/src/utils.c
index 7f2831b..53a9ebf 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -45,6 +45,7 @@ int pit_string_vsnprintf(char *buf, size_t len, char *format, va_list ap) {
                 if (length_mod == 'l') arg = va_arg(ap, long); else arg = va_arg(ap, int);
                 if (arg == 0) { WRITE('0') }
                 else {
+                    if (arg < 0) { WRITE('-'); arg = -arg; }
                     while (arg != 0) { WRITE_SCRATCH('0' + (char) (arg % 10)); arg /= 10; }
                     while (sidx > 0) { WRITE(scratch[sidx - 1]); sidx -= 1; }
                 }