From 1b8abc8fa02acfa8f324a0dff963a52b671deea8 Mon Sep 17 00:00:00 2001
From: Jeremy Rand <jeremy@moleman>
Date: Wed, 24 Jul 2013 18:01:04 -0500
Subject: [PATCH] Finish implementation on add

---
 Makefile      |  5 ++---
 abCalcMain.c  |  8 +++++---
 abCalcOp.c    |  5 +++++
 abCalcOp.h    | 17 +++++++++++++++++
 abCalcOpAdd.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 abCalcStack.c | 11 ++++++++---
 6 files changed, 78 insertions(+), 10 deletions(-)

diff --git a/Makefile b/Makefile
index 4c2b83a..84025f9 100644
--- a/Makefile
+++ b/Makefile
@@ -13,11 +13,10 @@ abCalcExprInt.o: abCalcExpr.h abCalcMode.h abCalcExprInt.h
 abCalc.o: abCalc.h abCalcExpr.h abCalcMode.h abCalcExprReal.h abCalcExprInt.h \
          abCalcStack.h abCalcOp.h abCalcError.h
 abCalcMain.o: abCalc.h abCalcStack.h abCalcExpr.h abCalcOp.h abCalcError.h
-abCalcOp.o: abCalcOp.h abCalcOpAdd.h
-abCalcOpAdd.o: abCalcOp.h abCalcOpAdd.h
+abCalcOp.o: abCalcOp.h abCalcError.h abCalcExpr.h abCalcStack.h abCalcOpAdd.h
+abCalcOpAdd.o: abCalcOp.h abCalcError.h abCalcOpAdd.h
 abCalcError.o: abCalcError.h
 
-CFLAGS=-g
 
 $(NAME): $(OBJS)
 	cc -o $(NAME) $(OBJS)
diff --git a/abCalcMain.c b/abCalcMain.c
index d6c1c49..489647f 100644
--- a/abCalcMain.c
+++ b/abCalcMain.c
@@ -31,7 +31,7 @@ int main(void)
     abCalcInit();
 
     while (!timeToQuit) {
-        printf("Stack:\n");
+        printf("\n---------------------------\nStack:\n");
         depth = abCalcStackNumItems();
 
         if (depth == 0) {
@@ -45,11 +45,11 @@ int main(void)
 
         errorString = abCalcGetError();
         if (errorString != NULL) {
-            printf("\n   %s\n", errorString);
+            printf("\n   === %s ===\n", errorString);
             abCalcClearError();
         }
 
-        timeToQuit = 1;
+        printf("> ");
         if (fgets(gBuffer, sizeof(gBuffer), stdin) != NULL) {
             len = strlen(gBuffer);
             if ((gBuffer[len - 1] == '\r') ||
@@ -66,6 +66,8 @@ int main(void)
             } else {
                 abCalcRaiseError(abCalcSyntaxError, NULL);
             }
+        } else {
+            timeToQuit = 1;
         }
     }
 
diff --git a/abCalcOp.c b/abCalcOp.c
index b5766af..ed06342 100644
--- a/abCalcOp.c
+++ b/abCalcOp.c
@@ -8,6 +8,9 @@
 #include <string.h>
 
 #include "abCalcOp.h"
+#include "abCalcExpr.h"
+#include "abCalcError.h"
+#include "abCalcStack.h"
 
 #include "abCalcOpAdd.h"
 
@@ -52,3 +55,5 @@ abCalcOp *abCalcOpLookup(char *name)
 
     return NULL;
 }
+
+
diff --git a/abCalcOp.h b/abCalcOp.h
index 513812d..2f575ee 100644
--- a/abCalcOp.h
+++ b/abCalcOp.h
@@ -8,6 +8,23 @@
 #define ABCALCOP_H
 
 
+#define AB_CALC_OP_ONE_ARG(opName)                       \
+    abCalcExpr *expr;                                    \
+    if (abCalcStackNumItems() < 1) {                     \
+        abCalcRaiseError(abCalcTooFewArgsError, opName); \
+        return;                                          \
+    }                                                    \
+    expr = abCalcStackExprAt(0);
+
+#define AB_CALC_OP_TWO_ARGS(opName)                      \
+    abCalcExpr *expr1, *expr2;                           \
+    if (abCalcStackNumItems() < 2) {                     \
+        abCalcRaiseError(abCalcTooFewArgsError, opName); \
+        return;                                          \
+    }                                                    \
+    expr1 = abCalcStackExprAt(0);                        \
+    expr2 = abCalcStackExprAt(1);
+
 typedef struct abCalcOp {
     char *name;
     void (*execute)(void);
diff --git a/abCalcOpAdd.c b/abCalcOpAdd.c
index 82d3907..9bb185b 100644
--- a/abCalcOpAdd.c
+++ b/abCalcOpAdd.c
@@ -7,7 +7,11 @@
 #include <stdio.h>
 
 #include "abCalcOpAdd.h"
+
 #include "abCalcOp.h"
+#include "abCalcError.h"
+#include "abCalcExpr.h"
+#include "abCalcStack.h"
 
 
 #define OP_NAME "+"
@@ -24,5 +28,41 @@ void abCalcOpAddInit(void)
 
 void addExecute(void)
 {
-    printf("In add!\n");
+    abCalcExpr result;
+    char expr1Real = 0;
+    char expr2Real = 0;
+    AB_CALC_OP_TWO_ARGS(OP_NAME);
+
+    if (expr1->type == abCalcExprTypeReal) {
+        expr1Real = 1;
+    } else if (expr1->type != abCalcExprTypeInt) {
+        abCalcRaiseError(abCalcBadArgTypeError, OP_NAME);
+        return;
+    }
+
+    if (expr2->type == abCalcExprTypeReal) {
+        expr2Real = 1;
+    } else if (expr2->type != abCalcExprTypeInt) {
+        abCalcRaiseError(abCalcBadArgTypeError, OP_NAME);
+        return;
+    }
+
+    if ((expr1Real) && (expr2Real)) {
+        result.type = abCalcExprTypeReal;
+        result.u.real = expr1->u.real + expr2->u.real;
+    } else {
+        result.type = abCalcExprTypeInt;
+
+        if (expr1Real) {
+            result.u.integer = (abCalcIntType)expr1->u.real + expr2->u.integer;
+        } else if (expr2Real) {
+            result.u.integer = expr1->u.integer + (abCalcIntType)expr2->u.real;
+        } else {
+            result.u.integer = expr1->u.integer + expr2->u.integer;
+        }
+    }
+
+    abCalcStackExprPop(NULL);
+    abCalcStackExprPop(NULL);
+    abCalcStackExprPush(&result);
 }
diff --git a/abCalcStack.c b/abCalcStack.c
index ad857de..5d7216d 100644
--- a/abCalcStack.c
+++ b/abCalcStack.c
@@ -45,12 +45,17 @@ abCalcExpr *abCalcStackExprPush(abCalcExpr *expr)
 abCalcExpr *abCalcStackExprPop(abCalcExpr *expr)
 {
     abCalcExpr *result = NULL;
-    if ((gStackNumItems > 0) &&
-        (expr != NULL)) {
-        gStackNumItems--;
+
+    if (gStackNumItems < 1)
+        return NULL;
+
+    gStackNumItems--;
+
+    if (expr != NULL) {
         result = expr;
         memcpy(expr, &(gStack[gStackNumItems]), sizeof(*expr));
     }
+
     return result;
 }