M core/interpreter.nim → core/interpreter.nim

@@ -68,7 +68,7 @@ q.scope = new MinScope
   q.scope.name = id
   q.scope.parent = i.scope
 
-template withScope*(i: In, id: string, q: MinValue, body: stmt): stmt {.immediate.}=
+template createScope*(i: In, id: string, q: MinValue, body: stmt): stmt {.immediate.} =
   q.scope = new MinScope
   q.scope.name = id
   q.scope.parent = i.scope
@@ -78,6 +78,14 @@ i.scope = q.scope
   body
   #i.debug "[scope] " & scope.fullname
   i.scope = scope
+
+template withScope*(i: In, q: MinValue, body: stmt): stmt {.immediate.} =
+  #i.debug "[scope] " & q.scope.fullname
+  let origScope = i.scope
+  i.scope = q.scope
+  body
+  #i.debug "[scope] " & scope.fullname
+  i.scope = origScope
 
 proc copystack*(i: MinInterpreter): MinStack =
   var s = newSeq[MinValue](0)
@@ -196,7 +204,7 @@ val = i.parser.parseMinValue
     i.push val
 
 proc unquote*(i: In, name: string, q: var MinValue) =
-  i.withScope(name, q): 
+  i.createScope(name, q): 
     for v in q.qVal:
       i.push v
 

M lib/min_lang.nim → lib/min_lang.nim

@@ -135,6 +135,13 @@ if not file.endsWith(".min"):
       file = file & ".min"
     i.load i.pwd.joinPath(file)
 
+ .symbol("with") do (i: In):
+   var qscope, qprog: Minvalue
+   i.reqTwoQuotations qscope, qprog
+   i.unquote("<with-scope>", qscope)
+   i.withScope(qscope):
+     i.unquote("<with-program>", qprog)
+
   .symbol("call") do (i: In):
     var symbols, target: MinValue
     i.reqTwoQuotations symbols, target

M lib/prelude.min → lib/prelude.min

@@ -84,3 +84,4 @@ ((ipv6 stream tcp) socket)   :tcp6-socket
 ((ipv4 dgram tcp) socket)    :udp-socket
 ((ipv6 dgram tcp) socket)    :udp6-socket
 
+

M tests/lang.min → tests/lang.min

@@ -3,7 +3,7 @@ #test
 
 "lang" describe
 
-  (symbols size 178 ==) assert
+  (symbols size 179 ==) assert
 
   (sigils size 10 ==) assert
 
@@ -116,6 +116,8 @@ (8 factorial)
     (12 factorial)
     (9 factorial)
     ) ->> (40320 479001600 362880) ==) assert
+
+  ((a b +) (4 :a 5 :b) with 9 ==) assert
 
   report
   ; Tidy up