Forbid leading zeroes in int literal

2 files changed, 16 insertions, 0 deletions

diff --git a/src/main/java/org/shedlang/compiler/parser/IntLiteralCannotHaveLeadingZeroesError.java b/src/main/java/org/shedlang/compiler/parser/IntLiteralCannotHaveLeadingZeroesError.java
new file mode 100644
index 00000000..28421cad
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/parser/IntLiteralCannotHaveLeadingZeroesError.java
@@ -0,0 +1,10 @@
+package org.shedlang.compiler.parser;
+
+import org.shedlang.compiler.errors.SourceError;
+import org.shedlang.compiler.sources.Source;
+
+public class IntLiteralCannotHaveLeadingZeroesError extends SourceError {
+    public IntLiteralCannotHaveLeadingZeroesError(Source source) {
+        super("int literal cannot have leading zeroes", source);
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/parser/Parser.java b/src/main/java/org/shedlang/compiler/parser/Parser.java
index 763d0a01..fcc92d99 100644
--- a/src/main/java/org/shedlang/compiler/parser/Parser.java
+++ b/src/main/java/org/shedlang/compiler/parser/Parser.java
@@ -481,6 +481,12 @@ public class Parser {
         var end = tokens.position();
         var source = start.to(end);
 
+        if (string.length() > 1 && string.startsWith("0")) {
+            throw new IntLiteralCannotHaveLeadingZeroesError(source);
+        } else if (string.length() > 2 && string.startsWith("-0")) {
+            throw new IntLiteralCannotHaveLeadingZeroesError(source);
+        }
+
         return new UntypedIntLiteralNode(value, source);
     }