add dbg macro

Technologicat · Technologicat · commit 431552c60713 · 2019-04-04T16:19:11.000+03:00
diff --git a/unpythonic/syntax/__init__.py b/unpythonic/syntax/__init__.py
@@ -24,7 +24,7 @@
                    dlet as _dlet, dletseq as _dletseq, dletrec as _dletrec, \
                    blet as _blet, bletseq as _bletseq, bletrec as _bletrec
 from .letsyntax import let_syntax_expr, let_syntax_block, block, expr
-from .nb import nb as _nb
+from .nb import nb as _nb, dbg as _dbg
 from .prefix import prefix as _prefix
 from .tailtools import autoreturn as _autoreturn, tco as _tco, \
                        continuations as _continuations, call_cc
@@ -1424,6 +1424,11 @@ def nb(tree, args, **kw):
     """
     return _nb(body=tree, args=args)
 
+@macros.block
+def dbg(tree, args, **kw):
+    """[syntax, block] TODO: document"""  # TODO: document
+    return _dbg(body=tree, args=args)
+
 # -----------------------------------------------------------------------------
 
 @macros.block
diff --git a/unpythonic/syntax/nb.py b/unpythonic/syntax/nb.py
@@ -5,9 +5,10 @@
 
 # This is the kind of thing thinking with macros does to your program. ;)
 
-from ast import Expr
+from ast import Expr, Call, Name
 
-from macropy.core.quotes import macros, q, ast_literal
+from macropy.core.quotes import macros, q, u, ast_literal
+from macropy.core.walkers import Walker
 
 def nb(body, args):
     p = args[0] if args else q[print]  # custom print function hook
@@ -26,3 +27,27 @@ def nb(body, args):
                 theprint(_)
         newbody.extend(newstmts)
     return newbody
+
+# with dbg:
+#     x = 3
+#     print(x)   # --> "x: <value>"
+#
+# with dbg(prt):
+#     x = 3
+#     prt(x)     # --> prt(name, value)
+#
+def dbg(body, args):
+    p = args[0] if args else q[print]  # custom print function hook
+    if type(p) is not Name:
+        assert False, "The print function can only be specified by a bare name"
+    theid = p.id
+
+    @Walker
+    def transform(tree, *, stop, **kw):
+        if type(tree) is Call and type(tree.func) is Name and tree.func.id == theid and \
+           len(tree.args) == 1 and type(tree.args[0]) is Name:
+            varname = q[u[tree.args[0].id]]
+            tree.args.insert(0, varname)
+        return tree
+
+    return [transform.recurse(stmt) for stmt in body]
diff --git a/unpythonic/syntax/test/test_nb.py b/unpythonic/syntax/test/test_nb.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-from ...syntax import macros, nb
+from ...syntax import macros, nb, dbg
 
 def test():
     with nb:
@@ -23,6 +23,15 @@ def test():
             3 * _
             assert _ == 3 * x * y
 
+    with dbg:
+        x = 3
+        print(x)
+
+    prt = lambda *args: print(*args)
+    with dbg(prt):
+        x = 5
+        prt(x)
+
     print("All tests PASSED")
 
 if __name__ == '__main__':
