M core/utils.nim → core/utils.nim

@@ -66,6 +66,9 @@ 
 proc raiseRuntime*(msg: string, qVal: var seq[MinValue]) =
   raise MinRuntimeError(msg: msg, qVal: qVal)
 
+proc raiseEmptyStack*() =
+  raise MinEmptyStackError(msg: "Insufficient items on the stack")
+
 proc getString*(v: MinValue): string =
   if v.isSymbol:
     return v.symVal

M lib/min_stack.nim → lib/min_stack.nim

@@ -13,6 +13,8 @@ .symbol("id") do (i: In):
     discard
   
   .symbol("pop") do (i: In):
+    if i.stack.len < 1:
+      raiseEmptyStack()
     discard i.pop
   
   .symbol("dup") do (i: In):
@@ -26,6 +28,8 @@ i.unquote("<dip>", q)
     i.push v
   
   .symbol("swap") do (i: In):
+    if i.stack.len < 2:
+      raiseEmptyStack()
     let a = i.pop
     let b = i.pop
     i.push a

M lib/prelude.min → lib/prelude.min

@@ -50,7 +50,6 @@ 'filter       :select
 'clear        :empty
 'cons         :prepend
 'size         :length
-'swap         :<>
 
 ; Mathematical Operators
 (1 +)           :succ
@@ -81,7 +80,6 @@ (print pop)                                     :print!
 (put pop)                                       :put!
 (:ms :q :check (check) (ms sleep q) while)      :interval
 (call pop)                                      :call!
-(swap pop)                                      :<!>
 
 ; Socket constructors
 ((ipv4 stream tcp) ^socket)   :tcp-socket

M tests/lang.min → tests/lang.min

@@ -7,7 +7,7 @@ 
   "Total Symbols: " print! symbols size put!
   "  Total Sigils: " print! sigils size put!
 
-  (symbols size 182 ==) assert
+  (symbols size 180 ==) assert
 
   (sigils size 12 ==) assert