Merge branch 'division'

Implement the division feature and fix left priority issue

eval.l

@@ -15,7 +15,7 @@ VOID [ \n\t]
 %%
 
 [0-9]+      yylval = atoi(yytext); return number; // Number token
-[-*+()=]    return yytext[0]; // Operators
+[-*+()=/]   return yytext[0]; // Operators
 {VOID}+     ; // Skip white characters
 .           fprintf(stderr, "Input '%c' unknown\n", yytext[0]); // Fallback error
 

eval.y

@@ -29,17 +29,20 @@ EXPR_CALCS	: EXPR_CALC
 EXPR_CALC	: EXPR '=' 	{ printf("%d\n", $1); }
 		;
 
-EXPR	: EXPR '+' EXPR		{$$ = $1 + $3;}
-	| EXPR '-' EXPR		{$$ = $1 - $3;}
-	| FACTOR
+EXPR	: EXPR '+' FACTOR	{$$ = $1 + $3;}
+	| EXPR '-' FACTOR	{$$ = $1 - $3;}
+        | FACTOR
 	;
 
-FACTOR	: number		{$$ = $1;}
-	| FACTOR '*' FACTOR	{$$ = $1 * $3;}
-	| FACTOR '/' FACTOR	{$$ = $1 / $3;}
-	| '(' EXPR ')'		{$$ = $2;}
+FACTOR	: FACTOR '*' ATOM	{$$ = $1 * $3;}
+	| FACTOR '/' ATOM	{if ($3 == 0) $$ = $1; else $$ = $1 / $3;}
+        | ATOM
 	;
 
+ATOM    : number                {$$ = $1;}
+	| '(' EXPR ')'		{$$ = $2;}
+        ;
+
 %%
 #include <stdio.h>
 #include "eval.tab.h"

test.bats

@@ -15,6 +15,11 @@
 	[ "$result" = "-1" ]
 }
 
+@test "Substraction with left priority" {
+        result="$(echo '8 - 2 - 1 =' | ./eval.out)"
+        [ "$result" = "5" ]
+}
+
 @test "Multiplication priority over addition" {
 	result="$(echo '1+2*3=' | ./eval.out)"
 	[ "$result" = "7" ]
@@ -52,14 +57,38 @@
 }
 
 @test "Basic division" {
-        skip "Feature not implemented"
 	result="$(echo '42 / 7 =' | ./eval.out)"
 	[ "$result" = "6" ]
 }
 
 @test "Basic truncated division" {
-        skip "Feature not implemented"
 	result="$(echo '16 / 3 =' | ./eval.out)"
 	[ "$result" = "5" ]
 }
 
+@test "Division with left priority" {
+        result="$(echo '8 / 4 / 2 =' | ./eval.out)"
+        [ "$result" = "1" ]
+}
+
+@test "Division by zero" {
+        # To improve
+        result="$(echo '42 / 0 =' | ./eval.out)"
+        [ "$result" = "42" ]
+}
+
+@test "Complex division" {
+	result="$(echo '192 / 3 / 16 =' | ./eval.out)"
+	[ "$result" = "4" ]
+}
+
+@test "Complex truncated division" {
+	result="$(echo '182 / 3 / 15 =' | ./eval.out)"
+	[ "$result" = "4" ]
+}
+
+@test "Mixed operation with * + / -" {
+	result="$(echo '15 * (1 + 1 + 1 + 4 - 2*2) / 3 / 15 =' | ./eval.out)"
+	[ "$result" = "1" ]
+}
+