M lib/min_lang.nim → lib/min_lang.nim

@@ -178,6 +178,11 @@ qscope.scope.symbols[sym] = MinOperator(kind: minProcOp, prc: op)
 
   ### End of symbols not present in minimin
 
+  def.symbol("expect-empty-stack") do (i: In):
+    let l = i.stack.len
+    if l != 0:
+      raiseInvalid("Expected empty stack, found $# elements instead" % $l)
+
   def.symbol("exit") do (i: In):
     let vals = i.expect("int")
     quit(vals[0].intVal.int)
@@ -915,6 +920,9 @@ i.push("quote-bind".newSym)
 
   def.symbol("=") do (i: In):
     i.push("quote-define".newSym)
+    
+  def.symbol("=-=") do (i: In):
+    i.push("expect-empty-stack".newSym)
 
   def.symbol(":") do (i: In):
     i.push("define".newSym)

M next-release.md → next-release.md

@@ -5,3 +5,4 @@ * Added **invoke** symbol (and **\*** sigil) to easily call a symbol defined in a module or dictionary, e.g. `*mymodule/mymethod`.
 * Fixed library installation via nimble
 * Fixed error handling and stack trace for **start-server** symbol.
 * Added the possibility to bundle assets in a compiled min program by specifying tbe **-a** (or **--asset-path**) option.
+* Added **expect-empty-stack** (**=-=**) symbol.

M site/contents/reference-lang.md → site/contents/reference-lang.md

@@ -38,6 +38,8 @@ {#alias||><||infix-dequote#}
 
 {#alias||=>||apply#}
 
+{#alias||=-=||expect-empty-stack#}
+
 {#sig||#||quote-bind#}
 
 {#alias||#||quote-bind#}
@@ -139,6 +141,10 @@ > >
 > > the following program evaluates to `true`:
 > > 
 > > `(int string num) expect (3.4 "test" 1) ==`#}
+
+{#op||expect-empty-stack||{{null}}||{{null}}||
+Raises an error if the stack is not empty.#}
+
 
 {#op||float||{{any}}||{{flt}}||
 > Converts {{any}} to an integer value based on the following rules: