diff --git a/src/object.c b/src/object.c
index f0692b9..de21cd2 100644
--- a/src/object.c
+++ b/src/object.c
@@ -824,6 +824,9 @@ errorWithAllocatedContextLineNo(enum errorCode code, char* context, int lineNo,
 
 inline Object errorWithContextLineNo(enum errorCode code, const char* context, int lineNo, const char* fileName)
 {
+    if (!context) {
+        context = "";
+    }
     char* copiedContext = malloc(sizeof(char) * ERR_LEN);
     strcpy(copiedContext, context);
     return errorWithAllocatedContextLineNo(code, copiedContext, lineNo, fileName);
diff --git a/src/pebblisp.c b/src/pebblisp.c
index 252b19d..8feeafe 100644
--- a/src/pebblisp.c
+++ b/src/pebblisp.c
@@ -328,24 +328,24 @@ Object structAccess(Object* params, unused int length, unused struct Environment
 Result parse(struct Slice* slices)
 {
     struct Slice* token = slices;
-    if (token && token->text) {
-        struct Slice* rest = &slices[1];
-        if (token->text[0] == '\'' && token->text[1] == '(') {
-            Result r = readSeq(&slices[2]);
-            if (r.obj.type == TYPE_LIST) {
-                r.obj.type = TYPE_SLIST;
-            }
-            return r;
-        } else if (token->text[0] == '(') {
-            return readSeq(rest);
-        } else {
-            Result r = parseAtom(token);
-            r.slices = &r.slices[1];
-            return r;
-        }
-    } else {
+    if (!token || !token->text) {
         return (Result) { errorObject(NULL_PARSE), NULL };
     }
+
+    struct Slice* rest = &slices[1];
+    if (token->text[0] == '\'' && token->text[1] == '(') {
+        Result r = readSeq(&slices[2]);
+        if (r.obj.type == TYPE_LIST) {
+            r.obj.type = TYPE_SLIST;
+        }
+        return r;
+    } else if (token->text[0] == '(') {
+        return readSeq(rest);
+    } else {
+        Result r = parseAtom(token);
+        r.slices = &r.slices[1];
+        return r;
+    }
 }
 
 #ifndef NO_SUGAR
@@ -382,33 +382,47 @@ Result readSeq(struct Slice* tokens)
     }
 }
 
-Object parseDecimal(struct Slice* s)
+int hexChar(char c)
 {
-    int num = 0;
-    for (int i = 0; i < s->length; i++) {
-        if (!isDigit(s->text[i])) {
-            return errorObject(BAD_NUMBER);
-        }
-        num *= 10;
-        num += s->text[i] - '0';
+    if (isDigit(c)) {
+        return c - '0';
     }
-    return numberObject(num);
+    if (c >= 'a' && c <= 'f') {
+        return c - 'a' + 10;
+    }
+    if (c >= 'A' && c <= 'F'){
+        return c - 'A' + 10;
+    }
+    return -1;
 }
 
-Object parseHex(struct Slice* s)
+int binChar(char c)
+{
+    if (c == '0' || c == '1') {
+        return c - '0';
+    }
+    return -1;
+}
+
+int decChar(char c)
+{
+    if (isDigit(c)) {
+        return c - '0';
+    }
+    return -1;
+}
+
+Object parseNum(int base, const char* text, int length, int (*func)(char))
 {
     int num = 0;
-    for (int i = 2; i < s->length; i++) {
-        const char c = s->text[i];
-        if (!isHex(c)) {
-            return errorObject(BAD_NUMBER);
-        }
-        num *= 16;
-        if (isDigit(c)) {
-            num += c - '0';
-        } else /* is hex */ {
-            num += c - 'a' + 10;
+    for (int i = 0; i < length; i++) {
+        const char c = text[i];
+        int value = func(c);
+        if (value < 0) {
+            throw(BAD_NUMBER, "at %s", text);
         }
+        num *= base;
+        num += value;
     }
     return numberObject(num);
 }
@@ -440,30 +454,28 @@ Result parseAtom(struct Slice* s)
     const char c = s->text[0];
     if (isDigit(c)) {
         if (c != '0' || s->length == 1) {
-            return (Result) { parseDecimal(s), s };
-#ifndef LOW_MEM
-        } else if (s->text[1] == 'x') {
-            return (Result) { parseHex(s), s };
-        } else if (s->text[1] == 'b') {
-            return (Result) { parseBin(s), s };
-#endif
-        } else {
-            return (Result) { errorWithContext(UNSUPPORTED_NUMBER_TYPE, s->text), s };
+            return (Result) { parseNum(10, s->text, s->length, decChar), s };
         }
-    } else if (s->length == 1 && c == 'T') {
+#ifndef LOW_MEM
+        if (s->text[1] == 'x') {
+            return (Result) { parseNum(16, s->text + 2, s->length - 2, hexChar), s };
+        }
+        if (s->text[1] == 'b') {
+            return (Result) { parseNum(2, s->text + 2, s->length - 2, binChar), s };
+        }
+#endif
+        return (Result) { errorWithContext(UNSUPPORTED_NUMBER_TYPE, s->text), s };
+    }
+    if (s->length == 1 && c == 'T') {
         return (Result) { trueObject(), s };
-    } else if (s->length == 1 && c == 'F') {
+    }
+    if (s->length == 1 && c == 'F') {
         return (Result) { falseObject(), s };
-    } else if (c == '"'/* || c == '\''*/) {
+    }
+    if (c == '"') {
         return (Result) { objFromSlice(s->text, s->length), s };
-    } else if (s->text[s->length] == '.') {
-        /*
-        struct InlinedFunction f ={
-            .func = structAccess,
-            .arguments = malloc(sizeof(Object) * 2),
-            .argCount = 2,
-        };
-        f.arguments[0] = symFromSlice(s->text, s->length);
+    }
+    if (s->text[s->length] == '.') {
         struct Slice* next = s + 2;
         f.arguments[1] = stringFromSlice(next->text, next->length);
 
@@ -523,7 +535,7 @@ Object parseEval(const char* input, struct Environment* env)
         cleanObject(&obj);
         Object parsed = parse(tok).obj;
         if (parsed.type == TYPE_ERROR) {
-            obj = parsed; // TODO Check necessity
+            obj = parsed;
 #ifdef STANDALONE
             obj.error->plContext = malloc(sizeof(struct Slice));
             *obj.error->plContext = *lastOpen;
diff --git a/src/plfunc.c b/src/plfunc.c
index 298f7fb..6561f64 100644
--- a/src/plfunc.c
+++ b/src/plfunc.c
@@ -107,7 +107,7 @@ Object at(Object* params, unused int length, unused struct Environment* env)
         return cloneObject(*found);
     }
 
-    return errorObject(INDEX_PAST_END);
+    throw(INDEX_PAST_END, "Tried to access index %ld from list of len %d", index.number, listLength(&list));
 }
 
 Object rest(Object* params, unused int length, unused struct Environment* env)
diff --git a/src/tokens.c b/src/tokens.c
index e0a55bf..0c6433e 100644
--- a/src/tokens.c
+++ b/src/tokens.c
@@ -18,7 +18,7 @@ int isSingle(const char c)
     int i = 0;
     while (singleTokens[i] != '\0') {
         if (singleTokens[i] == c) {
-            return singleTokens[i];
+            return 1;
         }
         i++;
     }
@@ -30,11 +30,6 @@ int isDigit(const char c)
     return c >= '0' && c <= '9';
 }
 
-int isHex(const char c)
-{
-    return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f');
-}
-
 int isWhitespace(const char c)
 {
     return c == ' ' || c == '\t' || c == '\n';