Merge pull request #863 from farhaven/read-str

Add read-str

docs/language/core.rst

@@ -1065,6 +1065,21 @@ if *from-file* ends before a complete expression can be parsed.
    hyfriends!
    EOF!
 
+read-str
+--------
+
+Usage: ``(read-str "string")``
+
+This is essentially a wrapper around `read` which reads expressions from a
+string:
+
+.. code-block:: hy
+
+   => (read-str "(print 1)")
+   (u'print' 1L)
+   => (eval (read-str "(print 1)"))
+   1
+   =>
 
 .. _remove-fn:
 

hy/core/language.hy

@@ -28,6 +28,9 @@
 (import collections)
 (import [fractions [Fraction :as fraction]])
 (import sys)
+(if-python2
+  (import [StringIO [StringIO]])
+  (import [io [StringIO]]))
 (import [hy._compat [long-type]]) ; long for python2, int for python3
 (import [hy.models.cons [HyCons]]
         [hy.models.symbol [HySymbol]]
@@ -382,6 +385,12 @@
       (else (if parsed (break)))))
     parsed)
 
+
+(defn read-str [input]
+  "Reads and tokenizes first line of input"
+  (read :from-file (StringIO input)))
+
+
 (defun Botsbuildbots () (Botsbuildbots))
 
 (defn zipwith [func &rest lists]
@@ -423,6 +432,6 @@
                  identity inc input instance? integer integer? integer-char?
                  interleave interpose iterable? iterate iterator? keyword
                  keyword? last list* macroexpand macroexpand-1 map merge-with
-                 name neg? nil? none? nth numeric? odd? pos? range read remove
+                 name neg? nil? none? nth numeric? odd? pos? range read read-str
-                 repeat repeatedly rest reduce second some string string?
+                 remove repeat repeatedly rest reduce second some string string?
                  symbol? take take-nth take-while zero? zip zip_longest zipwith])

tests/native_tests/language.hy

@@ -1186,6 +1186,10 @@
     (catch [e Exception]
       (assert (isinstance e EOFError)))))
 
+(defn test-read-str []
+  "NATIVE: test read-str"
+  (assert (= (read-str "(print 1)") '(print 1))))
+
 (defn test-keyword-creation []
   "NATIVE: Test keyword creation"
   (assert (= (keyword "foo") :foo))