From a9050fc9b9f91a0cddbd9cbbcc5907d1a9772567 Mon Sep 17 00:00:00 2001
From: Stepan Usatiuk <stepan@usatiuk.com>
Date: Sat, 23 Dec 2023 19:21:05 +0100
Subject: [PATCH] secd parser

---
 src/vm/src/Parser.cpp        | 51 +++++++++++++++++++++++++++++++-----
 test/vm/VMWithParserTest.cpp | 28 ++++++++++++++++++++
 2 files changed, 72 insertions(+), 7 deletions(-)

diff --git a/src/vm/src/Parser.cpp b/src/vm/src/Parser.cpp
index 7ff7fbf..6fa981d 100644
--- a/src/vm/src/Parser.cpp
+++ b/src/vm/src/Parser.cpp
@@ -43,6 +43,34 @@ void Parser::compileBody(const std::function<void(Cell *)> &sink) {
             int64_t loc = std::stoi(_tokenizer.getNext());
             if (_tokenizer.getNext() != ")") throw std::invalid_argument("Expected )");
             sink(_vm.makeCell<ConsCell>(_vm.makeCell<IntCell>(frame), _vm.makeCell<IntCell>(loc)));
+        } else if (token == "SEL") {
+            std::stack<Cell *> outt;
+            compileBody([&outt](Cell *cmd) { outt.emplace(cmd); });
+            std::stack<Cell *> outf;
+            compileBody([&outf](Cell *cmd) { outf.emplace(cmd); });
+
+            if (outt.empty()) throw std::invalid_argument("Function body empty");
+            if (outf.empty()) throw std::invalid_argument("Function body empty");
+
+            ConsCell *ttop = _vm.makeCell<ConsCell>(outt.top());
+            outt.pop();
+            while (!outt.empty()) {
+                _vm.push(ttop, outt.top());
+                outt.pop();
+            }
+
+            ConsCell *ftop = _vm.makeCell<ConsCell>(outf.top());
+            outf.pop();
+            while (!outf.empty()) {
+                _vm.push(ftop, outf.top());
+                outf.pop();
+            }
+
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::SEL));
+            sink(ttop);
+            sink(ftop);
+        } else if (token == "JOIN") {
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::JOIN));
         } else if (token == "LDF") {
             std::stack<Cell *> out;
 
@@ -59,22 +87,31 @@ void Parser::compileBody(const std::function<void(Cell *)> &sink) {
             }
             sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::LDF));
             sink(fntop);
-        } else if (token == "CONS") {
-            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::CONS));
         } else if (token == "AP") {
             sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::AP));
-        } else if (token == "ADD") {
-            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::ADD));
         } else if (token == "RET") {
             sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::RET));
+        } else if (token == "DUM") {
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::DUM));
+        } else if (token == "RAP") {
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::RAP));
+        } else if (token == "STOP") {
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::STOP));
+        } else if (token == "ADD") {
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::ADD));
+        } else if (token == "SUB") {
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::SUB));
+        } else if (token == "READCHAR") {
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::READCHAR));
         } else if (token == "PUTCHAR") {
             sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::PUTCHAR));
         } else if (token == "PUTNUM") {
             sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::PUTNUM));
-        } else if (token == "STOP") {
-            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::STOP));
+        } else if (token == "CONS") {
+            sink(_vm.makeCell<CommandCell>(CommandCell::CommandNum::CONS));
         } else {
-            if (token != ")")throw std::invalid_argument("Unknown token " + token);
+            if (token != ")")
+                throw std::invalid_argument("Unknown token " + token);
         }
     }
 }
diff --git a/test/vm/VMWithParserTest.cpp b/test/vm/VMWithParserTest.cpp
index 9a0ce9c..086f990 100644
--- a/test/vm/VMWithParserTest.cpp
+++ b/test/vm/VMWithParserTest.cpp
@@ -16,6 +16,20 @@ TEST(VMWithParserTest, BasicHello) {
     EXPECT_EQ(ssout.str(), "h");
 }
 
+TEST(VMWithParserTest, BasicBranch) {
+    std::stringstream ssin;
+    std::stringstream ssout;
+    {
+        VM vm(ssin, ssout);
+        Parser parser(vm);
+        parser.loadSecd(
+                "( LDC 1 SEL ( LDC 10 PUTNUM JOIN ) ( LDC 20 PUTNUM JOIN ) LDC 0 SEL ( LDC 30 PUTNUM JOIN ) ( LDC 40 PUTNUM JOIN ) STOP )");
+        vm.run();
+    }
+    ssout.flush();
+    EXPECT_EQ(ssout.str(), "1040");
+}
+
 TEST(VMWithParserTest, BasicFunction) {
     std::stringstream ssin;
     std::stringstream ssout;
@@ -27,4 +41,18 @@ TEST(VMWithParserTest, BasicFunction) {
     }
     ssout.flush();
     EXPECT_EQ(ssout.str(), "3");
+}
+
+TEST(VMWithParserTest, RecFunction) {
+    std::stringstream ssin;
+    std::stringstream ssout;
+    {
+        VM vm(ssin, ssout);
+        Parser parser(vm);
+        parser.loadSecd(
+                "( DUM NIL LDF ( LD ( 1 . 1 ) SEL ( LD ( 1 . 1 ) LDC -1 ADD SEL ( NIL LD ( 1 . 1 ) LDC -1 ADD CONS LD ( 2 . 1 ) AP NIL LD ( 1 . 1 ) LDC -2 ADD CONS LD ( 2 . 1 ) AP ADD JOIN ) ( LDC 1 JOIN ) JOIN ) ( LDC 0 JOIN ) RET ) CONS LDF ( NIL LDC 20 CONS LD ( 1 . 1 ) AP RET ) RAP PUTNUM STOP )");
+        vm.run();
+    }
+    ssout.flush();
+    EXPECT_EQ(ssout.str(), "6765");
 }
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