feat(sugar): equal sign minus like x=-1/x==-1

p.s. such a ast will be parsed as `=-`(x,1) in Nim

src/pylib/pysugar/stmt/exprRewrite.nim

@@ -147,13 +147,34 @@ proc toDict(e): NimNode =
     ), eles
   )
 
-
-template toPyExprImpl(atm: NimNode; toListCb): NimNode =
+proc rewriteEqualMinus(e; k=nnkAsgn): NimNode =
+  ## x==-1 -> x == -1
+  ## x=-1 -> x = -1
+
+  let lhs = e[1].toPyExpr
+  template rhs: NimNode = newCall("-", e[2].toPyExpr)
+  if e[0].eqIdent"=-":
+    k.newTree lhs, rhs
+  elif e[0].eqIdent"==-":
+    newCall "==", lhs, rhs
+  else: e
+
+proc callToPyExpr*(e): NimNode
+
+template toPyExprImpl(atm: NimNode; toListCb; equalMinusAs=nnkAsgn): NimNode =
   case atm.kind
   of nnkBracketExpr:
     rewriteSliceInBracket atm
   of nnkCommand:
     rewriteStrLitCat atm
+  of nnkCall:
+    callToPyExpr atm
+  of nnkPrefix:
+    nnkPrefix.newTree atm[0], atm[1].toPyExpr
+  of nnkPar:
+    nnkPar.newTree atm[0].toPyExpr
+  of nnkInfix:
+    rewriteEqualMinus atm, equalMinusAs
 
   of nnkTripleStrLit,
       nnkStrLit, nnkRStrLit:
@@ -171,3 +192,12 @@ template toPyExprImpl(atm: NimNode; toListCb): NimNode =
 proc toPyExpr*(atm: NimNode): NimNode = toPyExprImpl atm, toList
 proc toPyExprNoList*(atm: NimNode): NimNode = toPyExprImpl atm, rewriteEachEle
 
+proc argInCallToPyExpr(atm: NimNode): NimNode =
+  ## f(x=-1) needs to be rewritten as Call(ExprEqExpr(Ident"x", -1))
+  toPyExprImpl atm, toList, nnkExprEqExpr
+
+proc callToPyExpr*(e): NimNode =
+  result = e.copyNimNode
+  for i in e:
+    result.add i.argInCallToPyExpr
+

src/pylib/pysugar/stmt/tonim.nim

@@ -162,10 +162,7 @@ proc parsePyStmt*(mparser; statement: NimNode): NimNode =
     if statement[^1].kind == nnkStmtList:
       result.add parseBodyOnlyLast statement
     else:
-      var nStmt = statement.copyNimNode
-      for i in statement:
-        nStmt.add i.toPyExpr
-      result.add nStmt
+      result.add statement.callToPyExpr
   of nnkForStmt, nnkWhileStmt:
     result.add parseBodyOnlyLast statement
   elif statement.len == 0:

tests/testaments/pysugar/equalMinus.nim

@@ -0,0 +1,23 @@
+
+discard """
+  output: '''
+-1
+'''
+"""
+
+import pylib
+
+
+def g():
+    def f(x):
+      return x
+
+    print(f(x=-1))
+
+    x = 3==-1
+    assert not(5==-1)  ## NOTE: par is a must!
+    ## or it'll be `not(5) == -1` in Nim
+    assert not x
+
+g()
+