[builtins] Implement Dict => values() method (#1777)

* [doc] document existing methods

builtin/method_dict.py

@@ -27,3 +27,19 @@ def Call(self, rd):
 
         keys = [value.Str(k) for k in dictionary.keys()]  # type: List[value_t]
         return value.List(keys)
+
+
+class Values(vm._Callable):
+
+    def __init__(self):
+        # type: () -> None
+        pass
+
+    def Call(self, rd):
+        # type: (typed_args.Reader) -> value_t
+
+        dictionary = rd.PosDict()
+        rd.Done()
+
+        values = dictionary.values()  # type: List[value_t]
+        return value.List(values)

core/shell.py

@@ -744,7 +744,7 @@ def Main(
         'get': None,  # doesn't raise an error
         'erase': None,  # ensures it doesn't exist
         'keys': method_dict.Keys(),
-        'values': None,  # TODO
+        'values': method_dict.Values(),
 
         # I think items() isn't as necessary because dicts are ordered?
         # YSH code shouldn't use the List of Lists representation.

doc/ref/chap-type-method.md

@@ -138,27 +138,76 @@ rather than its value.
 
 ### append()
 
+Add an element to a list.
+
+    var fruits = :|apple banana pear|
+    call fruits->append("orange")
+    echo @fruits  # => apple banana pear orange
+
 ### pop()
 
+remove an element from a list and return it.
+
+    var fruits = :|apple banana pear orange|
+    var last = fruits->pop()  # "orange" is removed AND returned
+    echo $last                # => orange
+    echo @fruits              # => apple banana pear
+
 ### extend()
 
+Extend an existing list with the elements of another list.
+
+    var foods = :|cheese chocolate|
+    var fruits = :|apple banana|
+    call foods->extend(fruits)
+    echo @foods  # => cheese chocolate apple banana pear
+
 ### indexOf()
 
-Returns the first index of the element in the List, or -1 if it's not present.
+Returns the first index of the element in the list, or -1 if it's not present.
+
+    var names = :| Jane Peter Joana Sam |
+    echo $[names => indexOf("Sam")]    # => 3
+    echo $[names => indexOf("Simon")]  # => -1
 
 ### insert()
 
 ### remove()
 
 ### reverse()
 
+Reverses a list in place.
+
+    var fruits = :|apple banana pear|
+    call fruits->reverse()
+    echo @fruits  # => pear banana apple
 
 ## Dict
 
 ### keys()
 
+Returns all existing keys from a dict as a list of strings.
+
+    var en2fr = {
+      hello: "bonjour",
+      friend: "ami",
+      cat: "chat"
+    }
+    = en2fr => keys()
+    # => (List 0x4689)   ["hello","friend","cat"]
+
 ### values()
 
+Similar to `keys()`, but returns the values of the dictionary.
+
+    var person = {
+      name: "Foo",
+      age: 25,
+      hobbies: :|walking reading|
+    }
+    = en2fr => values()]
+    # => (List 0x4689)   ["Foo",25,["walking","reading"]]
+
 ### get()
 
 ### erase()

spec/ysh-methods.test.sh

@@ -71,6 +71,17 @@ pp line (en2fr => keys())
 (List)   ["hello","friend","cat"]
 ## END
 
+#### Dict => values()
+var en2fr = {}
+setvar en2fr["hello"] = "bonjour"
+setvar en2fr["friend"] = "ami"
+setvar en2fr["cat"] = "chat"
+pp line (en2fr => values())
+## status: 0
+## STDOUT:
+(List)   ["bonjour","ami","chat"]
+## END
+
 #### Separation of -> attr and () calling
 const check = "abc" => startsWith
 pp line (check("a"))