add PyImportFrom in surface syntax and get-strcutured-python; havn't …

…desugar yet [issue #3]
brownplt · Dec 23, 2012 · 52021df · 52021df
1 parent b3479d9
commit 52021df
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Showing 3 changed files with 52 additions and 6 deletions.
diff --git a/base/get-structured-python.rkt b/base/get-structured-python.rkt
@@ -336,6 +336,22 @@ structure that you define in python-syntax.rkt
                             (string->symbol (hash-ref x 'name))
                             (string->symbol as))))
                     names))]
+
+    ; largely the same with PyImport.
+    [(hash-table ('nodetype "ImportFrom")
+                 ('module module)
+                 ('names names)
+                 ('level level))
+     (PyImportFrom module
+                   (map (lambda (x)
+                          (hash-ref x 'name)))
+                   (map (lambda (x)
+                          (let ([as (hash-ref x 'asname)])
+                            (if (equal? as #\nul)
+                                (string->symbol (hash-ref x 'name))
+                                (string->symbol as))))
+                        names)
+                   level)]
 
     [(list (hash-table (k v) ...) ..2)
      (PySeq (map get-structured-python pyjson))]

diff --git a/base/python-desugar.rkt b/base/python-desugar.rkt
@@ -334,6 +334,29 @@
                                                           (list (PyStr (first names))))))))]))]
          (PySeq (helper names asnames (list)))))
 
+;;; desugar from module import id as id_alias
+;;; __tmp_module = __import__(module, globals(), locals(), [id], 0)
+;;; id_alias = __tmp_module.id
+(define (desugar-importfrom-py [module : string]
+                               [names : (listof string)]
+                               [asnames : (listof symbol)]
+                               [level : number]) : PyExpr
+  (PySeq (list)))
+;  (local [(define tmp-expr 
+;            (PyAssign (list (PyId '__tmp_module 'Store))
+;                      (PyApp (PyId '__import__ 'Load)
+;                             (list (PyStr module)
+;                                   (PyApp (PyId '__globals 'Load) (list))
+;                                   (PyApp (PyId '__locals 'Load) (list))
+;                                   ; list type of names
+;                                   level))))
+;          ;(define assign-exprs
+
+
+
+
+
+
 (define (rec-desugar [expr : PyExpr] [global? : boolean]
                      [env : IdEnv] [inclass? : boolean]) : DesugarResult 
   (begin ;(display expr) (display "\n\n")
@@ -871,13 +894,13 @@
                   [else (error 'desugar "We don't know how to delete identifiers yet.")]))]
 
     [PyImport (names asnames)
-              (rec-desugar
-               (desugar-import-py names asnames)
-               global?
-               env
-               inclass?)]
+              (rec-desugar (desugar-import-py names asnames) global? env inclass?)]
+
+    [PyImportFrom (module names asnames level)
+                  (rec-desugar (desugar-importfrom-py module names asnames level) global? env inclass?)]
     )))
 
+
 (define (desugar [expr : PyExpr]) : CExpr
   (type-case DesugarResult (rec-desugar expr true empty false)
     [DResult (expr env) expr]))

diff --git a/base/python-syntax.rkt b/base/python-syntax.rkt
@@ -72,8 +72,15 @@
   [PyNone]
   [PyBreak]
 
-  ; import, which is desugar to asname = __import__("name")
+  ; import, which desugar to asname = __import__("name")
   [PyImport (names : (listof string)) (asnames : (listof symbol))]
+  ; from import, which desugar to 
+  ; 1. _temp = __import__(...)
+  ; 2. asname = _temp.name
+  [PyImportFrom (module : string) 
+                (names : (listof string))
+                (asnames : (listof symbol))
+                (level : number)]
 )