From bc22ddab0d463209d6b6aae58be07c8a6df9e5d7 Mon Sep 17 00:00:00 2001 From: Clyne Sullivan Date: Tue, 26 Nov 2024 07:41:10 -0500 Subject: if else then --- forth.hpp | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'forth.hpp') diff --git a/forth.hpp b/forth.hpp index 3873c68..a9c55df 100644 --- a/forth.hpp +++ b/forth.hpp @@ -282,6 +282,16 @@ struct forth auto f_semic = [](auto) { *fth.here++ = 0; fth.compiling = false; }; auto f_comm = [](auto) { fth.sourcei = npos; }; auto f_cell = [](auto) { fth.push(sizeof(cell)); }; + auto f_jmp = [](auto) { + auto ptr = ++fth.ip; + fth.ip = *reinterpret_cast(ptr) - 1; + }; + auto f_jmp0 = [](auto) { + auto ptr = ++fth.ip; + + if (fth.pop() == 0) + fth.ip = *reinterpret_cast(ptr) - 1; + }; constexpr static word w_dict {"_d", f_dict}; constexpr static word w_add {"+", f_add, &w_dict}; @@ -308,8 +318,10 @@ struct forth constexpr static word w_semic {";", f_semic, &w_colon, word_base::immediate}; constexpr static word w_comm {"\\", f_comm, &w_semic, word_base::immediate}; constexpr static word w_cell {"cell", f_cell, &w_comm}; + constexpr static word w_jmp {"_jmp", f_jmp, &w_cell}; + constexpr static word w_jmp0 {"_jmp0", f_jmp0, &w_jmp}; - fth.latest = &w_cell; + fth.latest = &w_jmp0; fth.end = end_value; } -- cgit v1.2.3