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authorCliff Click <cliffc@acm.org>2023-10-29 10:45:20 -0700
committerDibyendu Majumdar <dibyendumajumdar@users.noreply.github.com>2023-11-01 18:56:50 +0000
commitf3bd82bdae3ebce5289b1a1bed9105c5bf04fdbe (patch)
treeede729aca8e374db986b0606e0756875ee668bf3 /chapter04/src/main/java/com
parent57d73a18aa2781d99098e5c13c5e2b8d25059aa4 (diff)
downloadSimple-f3bd82bdae3ebce5289b1a1bed9105c5bf04fdbe.tar.gz
Simple-f3bd82bdae3ebce5289b1a1bed9105c5bf04fdbe.zip
Fix div-by-0, some javadoc
higher level parsers can return null, but their return is ignored anycase. div-by-0 is defined to be 0, backported to ch2,3,4,5
Diffstat (limited to 'chapter04/src/main/java/com')
-rw-r--r--chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java9
-rw-r--r--chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java1
2 files changed, 5 insertions, 5 deletions
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
index 22167a87..1f562378 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -23,11 +23,10 @@ public class DivNode extends Node {
public Type compute() {
if (in(1)._type instanceof TypeInteger i0 &&
in(2)._type instanceof TypeInteger i1) {
- if (i0.isConstant() && i1.isConstant()) {
- if (i1.value() == 0)
- throw new IllegalArgumentException("Divide by zero");
- return TypeInteger.constant(i0.value()/i1.value());
- }
+ if (i0.isConstant() && i1.isConstant())
+ return i1.value() == 0
+ ? TypeInteger.ZERO
+ : TypeInteger.constant(i0.value()/i1.value());
return i0.meet(i1);
}
return TypeBot.BOTTOM;
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java b/chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java
index e23840e0..b53b1b29 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java
@@ -7,6 +7,7 @@ public class TypeInteger extends Type {
public final static TypeInteger TOP = new TypeInteger(false, 0);
public final static TypeInteger BOT = new TypeInteger(false, 1);
+ public final static TypeInteger ZERO= new TypeInteger(true, 0);
private final boolean _is_con;