diff options
Diffstat (limited to 'stdlib/parsing.ml')
| -rw-r--r-- | stdlib/parsing.ml | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/stdlib/parsing.ml b/stdlib/parsing.ml index 2b4d93ddb..44c7fb271 100644 --- a/stdlib/parsing.ml +++ b/stdlib/parsing.ml @@ -180,9 +180,15 @@ let peek_val env n = Obj.magic env.v_stack.(env.asp - n) let symbol_start_pos () = - if env.rule_len > 0 - then env.symb_start_stack.(env.asp - env.rule_len + 1) - else env.symb_end_stack.(env.asp) + let rec loop i = + if i <= 0 then env.symb_end_stack.(env.asp) + else begin + let st = env.symb_start_stack.(env.asp - i + 1) in + let en = env.symb_end_stack.(env.asp - i + 1) in + if st <> en then st else loop (i - 1) + end + in + loop env.rule_len ;; let symbol_end_pos () = env.symb_end_stack.(env.asp);; let rhs_start_pos n = env.symb_start_stack.(env.asp - (env.rule_len - n));; |