5 files changed, 19 insertions, 19 deletions
diff --git a/src/zisp/io/Parser.zig b/src/zisp/io/Parser.zig
index cddd397..29b8590 100644
--- a/src/zisp/io/Parser.zig
+++ b/src/zisp/io/Parser.zig
@@ -84,14 +84,14 @@ pub const Error = enum {
 
 pub const Context = struct {
     /// What to do next.
-    next: ?Fn = undefined,
+    next: ?Fn = null,
     /// For storing a context value, like datum to join in join syntax.
-    val: Value = undefined,
+    val: Value = value.none,
     /// For storing a context char, like list opening bracket.
-    char: u8 = undefined,
+    char: u8 = 0,
     /// Start index of list elements on current parse level, within the global
     /// list element accumulation array.
-    list_start: usize = undefined,
+    list_start: usize = 0,
     /// Are we in a comment?
     comment: bool = false,
 };
@@ -178,7 +178,7 @@ fn readNoEof(p: *Parser, comptime emsg: []const u8) !u8 {
 
 // Fake optional, for use in: while (readNoEofOpt()) |c| { }
 fn readNoEofOpt(p: *Parser, comptime emsg: []const u8) !?u8 {
-    return try p.read() orelse p.err(.UnexpectedEof, emsg);
+    return try p.readNoEof(emsg);
 }
 
 fn unread(p: *Parser, c: u8) void {
diff --git a/src/zisp/value.zig b/src/zisp/value.zig
index fc815bd..c16b937 100644
--- a/src/zisp/value.zig
+++ b/src/zisp/value.zig
@@ -27,8 +27,8 @@ const endian = builtin.target.cpu.arch.endian();
 const max = std.math.maxInt;
 
 /// Used to find the length of a rune or short string.
-pub fn sstrLen(x: u64) u8 {
-    const bytes: @Vector(8, u8) = @bitCast(x);
+pub fn sstrLen(v: *const Value) u8 {
+    const bytes: @Vector(8, u8) = @bitCast(v.bits);
     const nulls: @Vector(8, u8) = @splat(0);
     const comps: u8 = @bitCast(bytes == nulls);
     // Two bits will always be 0, since the actual short string starts at the
@@ -64,16 +64,16 @@ pub const Zptr = *align(16) anyopaque;
 /// Values for the lowest 4 bits of a heap pointer, indicating the heap type.
 pub const HeapType = enum(u4) {
     /// Unused so the 48-bit payload of a NaN-packed pointer is never zero and
-    /// cannot be confused for an actual NaN even in case of a null-index.
+    /// cannot be confused for an actual NaN even in case of a null index.
     _unused = 0,
 
-    /// Array of various types (see `Array` type for details)
+    /// Array of various types: see `ArrayPtr`.
     array,
 
     pub fn PtrType(self: HeapType) type {
         return switch (self) {
             .array => array.ArrayPtr,
-            else => @panic("not implemented"),
+            else => @panic("Invalid HeapType."),
         };
     }
 };
diff --git a/src/zisp/value/fixnum.zig b/src/zisp/value/fixnum.zig
index 0a6dd46..1929ba2 100644
--- a/src/zisp/value/fixnum.zig
+++ b/src/zisp/value/fixnum.zig
@@ -23,14 +23,14 @@ pub fn assert(v: Value) void {
 pub const min = std.math.minInt(i52) + 1;
 pub const max = std.math.maxInt(i52) - 1;
 
+fn checkValidRange(int: i64) bool {
+    return min < int and int < max;
+}
+
 fn assertValidRange(int: i64) void {
-    if (int < min) {
-        std.debug.print("int too small for fixnum: {}\n", .{int});
-        @panic("int too small for fixnum");
-    }
-    if (int > max) {
-        std.debug.print("int too large for fixnum: {}\n", .{int});
-        @panic("int too large for fixnum");
+    if (!checkValidRange(int)) {
+        std.debug.print("Fixnum out of range: {}\n", .{int});
+        @panic("Fixnum out of range.");
     }
 }
 
diff --git a/src/zisp/value/rune.zig b/src/zisp/value/rune.zig
index 89f6467..67124ea 100644
--- a/src/zisp/value/rune.zig
+++ b/src/zisp/value/rune.zig
@@ -50,7 +50,7 @@ pub fn packForced(s: []const u8) Value {
 
 pub fn unpack(v: *const Value) []const u8 {
     assert(v.*);
-    const len = value.sstrLen(v.bits);
+    const len = value.sstrLen(v);
     return v.bufRO()[ofs .. ofs + len];
 }
 
diff --git a/src/zisp/value/sstr.zig b/src/zisp/value/sstr.zig
index 59995f3..78a84e9 100644
--- a/src/zisp/value/sstr.zig
+++ b/src/zisp/value/sstr.zig
@@ -46,7 +46,7 @@ pub fn pack(s: []const u8) Value {
 
 pub fn unpack(v: *const Value) []const u8 {
     assert(v.*);
-    const len = value.sstrLen(v.bits);
+    const len = value.sstrLen(v);
     return v.bufRO()[ofs .. ofs + len];
 }