From 3c9fe1dfe5e96e0d23d98f96308de176ac5645fb Mon Sep 17 00:00:00 2001
From: Sleepwalking <alex_shef_31@mail.ru>
Date: Wed, 7 Feb 2024 17:22:49 +0100
Subject: [PATCH] done

---
 src/Expr.lama | 26 +++++++++++++++++++++++++-
 src/SM.lama   | 33 ++++++++++++++++++++++++++++++---
 src/Stmt.lama | 11 +++++++++--
 3 files changed, 64 insertions(+), 6 deletions(-)

diff --git a/src/Expr.lama b/src/Expr.lama
index b758035636..db86765919 100644
--- a/src/Expr.lama
+++ b/src/Expr.lama
@@ -13,6 +13,30 @@ import State;
 --        Const (int)                |
 --        Binop (string, expr, expr)
 
+public fun evalOp (op, left, right) {
+  case op of 
+      "+" -> left + right
+    | "-" -> left - right
+    | "*" -> left * right 
+    | "/" -> left / right
+    | "%" -> left % right
+    | "<" -> left < right
+    | ">" -> left > right
+    | "<=" -> left <= right
+    | ">=" -> left >= right
+    | "==" -> left == right
+    | "!=" -> left != right
+    | "&&" -> left && right
+    | "!!" -> left !! right
+    | o -> failure ("incorrect op\n")
+  esac
+}
+
 public fun evalExpr (st, expr) {
-  failure ("evalExpr not implemented\n")
+  case expr of 
+      Var (s) -> st (s) 
+    | Const (x) -> x
+    | Binop (op, left, right) -> evalOp(op, (evalExpr(st, left)), (evalExpr(st, right)))
+    | e -> failure ("incorrect expr\n")
+  esac 
 }
diff --git a/src/SM.lama b/src/SM.lama
index 5e9e82bd9e..bb234187ee 100644
--- a/src/SM.lama
+++ b/src/SM.lama
@@ -26,8 +26,23 @@ public fun showSM (prg) {
 
 -- Stack machine interpreter. Takes an SM-configuration and a program,
 -- returns a final configuration
+
+fun evalInsn (c@[stack, state, world], insn) {
+  case insn of 
+      ST (x) -> case stack of (z : s) -> [s, state <- [x, z], world] esac 
+    | LD (x) -> [state(x) : stack, state, world]
+    | CONST (x) -> [x : stack, state, world]
+    | BINOP (op) -> case stack of (y : (x : s)) -> [evalOp(op, x, y) : s, state, world] esac
+    | READ -> case readWorld(world) of [res, newWorld] -> [res : stack, state, newWorld] esac
+    | WRITE -> case stack of (z : s) -> [s, state, writeWorld(z, world)] esac
+  esac
+}
+
 fun eval (c, insns) {
-  failure ("SM eval not implemented\n")
+  case insns of 
+      {} -> c
+    | i : rest -> eval (evalInsn(c, i), rest)
+  esac
 }
 
 -- Runs a stack machine for a given input and a given program, returns an output
@@ -38,12 +53,24 @@ public fun evalSM (input, insns) {
 -- Compiles an expression into a stack machine code.
 -- Takes an expression, returns a list of stack machine instructions
 fun compileExpr (expr) {
-  failure ("compileExpr not implemented\n")
+  case expr of 
+      Var (x) -> {LD (x)}
+    | Const (x) -> {CONST (x)}
+    | Binop (op, left, right) -> compileExpr(left) +++ compileExpr(right) +++ {BINOP(op)}
+    | e -> failure ("incorrect expr (compileExpr)\n")
+  esac
 }
 
 -- Compiles a statement into a stack machine code.
 -- Takes a statement, returns a list of stack machine
 -- instructions.
 public fun compileSM (stmt) {
-  failure ("compileSM not implemented\n")
+  case stmt of 
+      Assn (x, expr) -> compileExpr(expr) +++ {ST (x)} 
+    | Seq (stmt1, stmt2) -> compileSM(stmt1) +++ compileSM(stmt2)
+    | Read (x) -> {READ} +++ {ST (x)}
+    | Write (expr) -> compileExpr(expr) +++ {WRITE}
+    | Skip -> {}
+    | s -> failure ("incorrect stmt (compileSM)\n")
+  esac
 }
diff --git a/src/Stmt.lama b/src/Stmt.lama
index 67ec6db9e6..14916e6783 100644
--- a/src/Stmt.lama
+++ b/src/Stmt.lama
@@ -16,8 +16,15 @@ import World;
 --        Read   (string)           |
 --        Write  (expr)             |
 
-fun eval (c, stmt) {
-  failure ("Stmt eval not implemented\n")
+fun eval (c@[state, world], stmt) {
+  case stmt of 
+      Assn (x, expr) -> [state <- [x, evalExpr(state, expr)], world]
+    | Seq (stmt1, stmt2) -> eval(eval(c, stmt1), stmt2)
+    | Read (x) -> case readWorld(world) of [res, newWorld] -> [state <- [x, res], newWorld] esac
+    | Write (expr) -> [state, writeWorld(evalExpr(state, expr), world)]
+    | Skip -> c
+    | s -> failure ("Stmt eval not implemented\n")
+  esac
 }
 
 -- Evaluates a program with a given input and returns an output