pit: Better double support

1 files changed, 34 insertions, 0 deletions

diff --git a/pit/src/parser.c b/pit/src/parser.c
index 0f9b167..6c633c9 100644
--- a/pit/src/parser.c
+++ b/pit/src/parser.c
@@ -46,6 +46,11 @@ static i64 digit_value(char c) {
     }
 }
 
+static double digit_value_double(char c) {
+    i64 ret = digit_value(c);
+    return (double) ret;
+}
+
 void pit_parser_from_lexer(pit_parser *ret, pit_lexer *lex) {
     ret->lexer = lex;
     ret->cur.token = ret->next.token = PIT_LEX_TOKEN_ERROR;
@@ -154,6 +159,35 @@ pit_value pit_parse(pit_runtime *rt, pit_parser *st, bool *eof) {
         }
         return pit_value_integer_new(rt, neg ? -total : total);
     }
+    case PIT_LEX_TOKEN_DOUBLE_LITERAL: {
+        i64 idx = st->cur.start;
+        double total = 0.0;
+        double point = 1.0;
+        bool after_point = false;
+        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 double literal"); return PIT_NIL;
+            }
+        } else if (c == '.') after_point = true;
+        total = digit_value_double(c);
+        while (idx < st->cur.end) {
+            c = st->lexer->input[idx++];
+            if (c == '.') {
+                after_point = true;
+            } else {
+                total *= 10.0;
+                total += digit_value_double(c);
+                if (after_point) point *= 10.0;
+            }
+        }
+        total /= point;
+        return pit_value_double_new(rt, neg ? -total : total);
+    }
     case PIT_LEX_TOKEN_STRING_LITERAL: {
         char buf[256] = {0};
         get_token_string(st, buf, sizeof(buf));