Implement the 3 missing "PUSH" opcodes.

All opcodes are now implemented.

Author: weaversam8

README.md

@@ -50,7 +50,7 @@ A few gotchas to look out for:
 - Make sure to open the compiled story file as a binary file (see the above example, use `open(filename, 'rb')`) in order for it to be properly parsed by the compiled protobuf library.
 - Unless you pass `autostart=False` to the runner when creating it, it will automatically start and run to the next choice point.
 
-Only a subset of Yarn Spinner opcodes are currently implemented. This will certainly change over time. The current status is:
+All Yarn Spinner opcodes are currently implemented. This may certainly change over time, if new opcodes are added to the language. The current status is:
 
 | OpCode           | Status                                                 |
 | ---------------- | ------------------------------------------------------ |
@@ -60,10 +60,10 @@ Only a subset of Yarn Spinner opcodes are currently implemented. This will certa
 | `RUN_COMMAND`    | ✅  Implemented in `runner.__run_command`    |
 | `ADD_OPTION`     | ✅  Implemented in `runner.__add_option`     |
 | `SHOW_OPTIONS`   | ✅  Implemented in `runner.__show_options`   |
-| `PUSH_STRING`    | 🚫  Not Implemented                          |
+| `PUSH_STRING`    | ✅  Implemented in `runner.__push_string`    |
 | `PUSH_FLOAT`     | ✅  Implemented in `runner.__push_float`     |
-| `PUSH_BOOL`      | 🚫  Not Implemented                          |
-| `PUSH_NULL`      | 🚫  Not Implemented                          |
+| `PUSH_BOOL`      | ✅  Implemented in `runner.__push_bool`      |
+| `PUSH_NULL`      | ✅  Implemented in `runner.__push_null`      |
 | `JUMP_IF_FALSE`  | ✅  Implemented in `runner.__jump_if_false`  |
 | `POP`            | ✅  Implemented in `runner.__pop`            |
 | `CALL_FUNC`      | ✅  Implemented in `runner.__call_func`      |

examples/variables.csv

@@ -0,0 +1 @@
+id,text,file,node,lineNumber

examples/variables.yarn

@@ -0,0 +1,7 @@
+title: Start
+---
+<<set $value_string to "string">>
+<<set $value_float to 1.25>>
+<<set $value_bool to true>>
+<<set $value_null to null>>
+===

examples/variables.yarnc

@@ -0,0 +1,18 @@
+import os
+from .context import YarnRunner
+
+compiled_yarn_f = open(os.path.join(os.path.dirname(
+    __file__), '../examples/variables.yarnc'), 'rb')
+names_csv_f = open(os.path.join(os.path.dirname(
+    __file__), '../examples/variables.csv'), 'r')
+
+runner = YarnRunner(compiled_yarn_f, names_csv_f)
+
+
+def test_variables():
+    assert not runner.has_line()
+    assert runner.finished
+    assert runner.variables["$value_string"] == "string"
+    assert runner.variables["$value_float"] == 1.25
+    assert runner.variables["$value_bool"] == True
+    assert runner.variables["$value_null"] is None

tests/test_variables.py

@@ -184,9 +184,18 @@ def __add_option(self, instruction):
     def __show_options(self, _instruction):
         self.paused = True
 
+    def __push_string(self, instruction):
+        self._vm_data_stack.insert(0, instruction.operands[0].string_value)
+
     def __push_float(self, instruction):
         self._vm_data_stack.insert(0, instruction.operands[0].float_value)
 
+    def __push_bool(self, instruction):
+        self._vm_data_stack.insert(0, instruction.operands[0].bool_value)
+
+    def __push_null(self, _instruction):
+        self._vm_data_stack.insert(0, None)
+
     def __jump_if_false(self, instruction):
         if self._vm_data_stack[0] == False:
             self.__jump_to(instruction)
@@ -285,10 +294,10 @@ def noop(instruction):
             Instruction.OpCode.RUN_COMMAND: self.__run_command,
             Instruction.OpCode.ADD_OPTION: self.__add_option,
             Instruction.OpCode.SHOW_OPTIONS: self.__show_options,
-            Instruction.OpCode.PUSH_STRING: noop,
+            Instruction.OpCode.PUSH_STRING: self.__push_string,
             Instruction.OpCode.PUSH_FLOAT: self.__push_float,
-            Instruction.OpCode.PUSH_BOOL: noop,
-            Instruction.OpCode.PUSH_NULL: noop,
+            Instruction.OpCode.PUSH_BOOL: self.__push_bool,
+            Instruction.OpCode.PUSH_NULL: self.__push_null,
             Instruction.OpCode.JUMP_IF_FALSE: self.__jump_if_false,
             Instruction.OpCode.POP: self.__pop,
             Instruction.OpCode.CALL_FUNC: self.__call_func,