Add pause command

SPEC.md

@@ -1,4 +1,4 @@
-# ChooseScript Specification v0.1.2
+# ChooseScript Specification v0.1.3
 
 ## Abstract
 
@@ -48,6 +48,7 @@ The following literal stems are commands. They MUST NOT be used as targets.
  - `input` - see section 2.4.1
  - `testequals` - see section 2.5
  - `check` - see section 2.5.1
+ - `pause` - see section 2.6
 
 ## 2. Commands
 
@@ -113,6 +114,11 @@ An undefined variable MUST fail all comparisons.
 A shorthand for `testequals <STEM> true`. If the variable represented by the 
 argument stem is not a boolean value, an error MUST be thrown.
 
+### 2.6. `pause [<NUMBER>]`
+
+Pause until user presses enter on their keyboard. Alternatively, pause for a 
+number of seconds defined by the argument number.
+
 ## 3. Implementation details
 
 The following are details of the implementation. These are meant to be 

choosescript.py

@@ -1,6 +1,6 @@
 from sly import Lexer as SlyLexer
 
-commands = ["goto","print","choose","input","set","testequals","check","beq","bne"]
+commands = ["goto","print","choose","input","set","testequals","check","beq","bne","pause"]
 
 class Lexer(SlyLexer):
 	tokens = { STEM, COMMAND, TARGET, STRING, NUMBER, BOOLEAN }
@@ -49,6 +49,7 @@ import sys
 def caller_id():
 	return sys._getframe(2).f_code.co_name
 
+import time
 class Evaluator:
 	def __init__(self): pass
 	def run(self,prog):
@@ -165,6 +166,11 @@ class Evaluator:
 		assert target.value in self.targets, f"Invalid branch target {target.value} at line {target.lineno}!"
 		if self.flag: return
 		self.pos = self.targets[target.value]
+	def command_pause(self):
+		if self.peek().type=="NUMBER":
+			time.sleep(self.next("NUMBER").value)
+		else:
+			input("Press enter to continue.")
 
 if __name__=="__main__":
 	_, file = sys.argv