✨

documentation/plthy.tex

@@ -47,8 +47,9 @@
         \item No valediction
         \item Unexpected token
         \item Random compiler error
-        \item Unknown builtin
         \item Wrong number of arguments for builtin
-        \item Unknown binop
+    \end{enumerate}
+    \begin{enumerate}[label={\textbf{C\protect\threedigits{\theenumi}:}}, leftmargin = *]
+        \item Because assertion incorrect
     \end{enumerate}
 \end{document}

examples/guessing_game.plthy

@@ -1,8 +1,8 @@
 hello|
-$do random<1;128;> -> n|
-$0 -> guess|
+set do random<1;128;> -> n|
+set 0 -> guess|
 until variable guess = variable n [
-    $do input<'guess: ';> -> guess|
+    set do input<'guess: ';> -> guess|
     do print<'too high';> if variable guess > variable n|
     do print<'too low';> if variable guess < variable n|
     do print<'correct!';> if variable guess = variable n|

plthy_impl/ast_nodes.py

@@ -2,6 +2,13 @@ import random
 
 from rply.token import BaseBox
 
+
+BUILTIN_ARGS = {
+    "print": "*",
+    "input" : "*",
+    "random": 2
+}
+
 def rep_join(l):
     format_string = ',\n'.join(
         [repr(i) if not isinstance(i, str) else i for i in l]
@@ -11,7 +18,6 @@ def rep_join(l):
         format_string = f"\n  {format_string}\n"
 
     return format_string
-
 class Exp(BaseBox):
     def eval(self, vtable, ftable):
         return vtable, ftable, None
@@ -86,8 +92,7 @@ class ExpABinop(Exp):
         elif self.op == "<":
             return vtable, ftable, r1 < r2
         else:
-            print(f"E007: Unknown binop {self.op}")
-            exit()
+            raise Exception(f"Unknown binop {self.op}")
 
 class ExpList(Exp):
     def __init__(self, expressions: list[Exp]):
@@ -143,9 +148,15 @@ class Command(BaseBox):
         return f"command()"
 
 class Builtin(Command):
-    def __init__(self, builtin: str, args: list[Exp]):
-        self.builtin = builtin
+    def __init__(self, builtin, args: list[Exp]):
+        self.builtin = builtin.value
         self.args = args
+        self.position = builtin.source_pos.lineno
+        expected_args = BUILTIN_ARGS[self.builtin]
+
+        if not (expected_args == "*" or expected_args == len(self.args)):
+            print(f"E005: Wrong number of arguments for builtin '{self.builtin}' ({len(self.args)}) at line {self.position}")
+            exit()
 
     def __repr__(self) -> str:
         return f"builtin({self.builtin}, {self.args})"
@@ -174,10 +185,6 @@ class Builtin(Command):
             result = input()
             return vtable, ftable, result
         elif self.builtin == "random":
-            if not len(self.args) == 2:
-                print(f"E006: Wrong number of arguments for builtin '{self.builtin}' ({len(self.args)})")
-                exit()
-
             vtable, ftable, r1 = self.args[0].eval(vtable, ftable)
             vtable, ftable, r2 = self.args[1].eval(vtable, ftable)
 
@@ -185,7 +192,7 @@ class Builtin(Command):
 
             return vtable, ftable, r
         else:
-            raise Exception(f"E005: Unknown builtin {self.builtin}")
+            raise Exception(f"Unknown builtin {self.builtin}")
 
 class Do(BaseBox):
     def __init__(self, command: Command):
@@ -309,6 +316,22 @@ class StatementIf(Statement):
         else:
             return vtable, ftable, result
 
+class StatementBecause(Statement):
+    def __init__(self, statement: Statement, condition):
+        self.statement = statement
+        self.condition = condition
+
+    def __repr__(self) -> str:
+        return f"if({self.statement}, {self.condition})"
+
+    def eval(self, vtable, ftable):
+        vtable, ftable, result = self.condition.eval(vtable, ftable)
+        if result:
+            return self.statement.eval(vtable, ftable)
+        else:
+            print("C001: Because assertion incorrect")
+            exit()
+
 class StatementUntil(Statement):
     def __init__(self, statement: Statement, condition):
         self.statement = statement

plthy_impl/lexer.py

@@ -9,13 +9,14 @@ KEYWORD_TOKENS = [("KEYWORD_"+i.upper(), i) for i in [
     "maybe",
     "do",
     "if",
-#    "because",
+    "because",
     "until",
     "define",
     "as",
     "variable",
     "return",
-    "argument"
+    "argument",
+    "set"
 ]]
 
 BUILTIN_TOKENS = [("BUILTIN", i) for i in [
@@ -50,7 +51,7 @@ SYMBOL_TOKENS = [
     ("SYMBOL_LT", r"\<"),
     ("SYMBOL_GT", r"\>"),
     ("SYMBOL_EQUALS", r"\="),
-    ("SYMBOL_DOLLAR", r"\$")
+#    ("SYMBOL_DOLLAR", r"\$")
 ]
 
 ALL_TOKENS = (

plthy_impl/parser.py

@@ -9,9 +9,9 @@ class Parser():
             [i[0] for i in ALL_TOKENS],
             precedence=[
                 ('left', ["KEYWORD_MAYBE", "KEYWORD_RETURN"]),
-                ('left', ["KEYWORD_IF", "KEYWORD_UNTIL", "KEYWORD_DEFINE", "KEYWORD_AS"]),
-                ('left', ["KEYWORD_DO", "BUILTIN"]),
-                ('left', ["SYMBOL_EQUALS", "SYMBOL_SET"]),
+                ('left', ["KEYWORD_IF", "KEYWORD_BECAUSE", "KEYWORD_UNTIL", "KEYWORD_DEFINE", "KEYWORD_AS"]),
+                ('left', ["KEYWORD_DO", "BUILTIN", "SYMBOL_SET"]),
+                ('left', ["SYMBOL_EQUALS"]),
                 ('left', ["SYMBOL_PLUS", "SYMBOL_MINUS"]),
                 ('left', ["SYMBOL_TIMES", "SYMBOL_DIVIDE", "SYMBOL_LT","SYMBOL_GT"])
             ]
@@ -33,7 +33,7 @@ class Parser():
             return [tokens[0]] + tokens[2]
 
         ## statement ##
-        @self.pg.production('statement : SYMBOL_DOLLAR expression SYMBOL_SET ID', precedence="SYMBOL_SET")
+        @self.pg.production('statement : KEYWORD_SET expression SYMBOL_SET ID', precedence="SYMBOL_SET")
         def statement_set(tokens):
             return ast_nodes.StatementSet(tokens[1], tokens[3].value)
 
@@ -49,6 +49,10 @@ class Parser():
         def statement_if(tokens):
             return ast_nodes.StatementIf(tokens[0], tokens[2])
 
+        @self.pg.production('statement : statement KEYWORD_BECAUSE expression')
+        def statement_because(tokens):
+            return ast_nodes.StatementBecause(tokens[0], tokens[2])
+
         @self.pg.production('statement : KEYWORD_UNTIL expression statement')
         def statement_until(tokens):
             return ast_nodes.StatementUntil(tokens[2],tokens[1])
@@ -68,7 +72,7 @@ class Parser():
         ## command ##
         @self.pg.production('command : BUILTIN SYMBOL_LT expressions SYMBOL_GT')
         def command_builtin(tokens):
-            return ast_nodes.Builtin(tokens[0].value, tokens[2])
+            return ast_nodes.Builtin(tokens[0], tokens[2])
 
         @self.pg.production('command : SYMBOL_QUOTE ID SYMBOL_QUOTE SYMBOL_LT expressions SYMBOL_GT')
         def command_call(tokens):
@@ -89,7 +93,7 @@ class Parser():
             return ast_nodes.ExpInt(int(tokens[0].value))
 
         @self.pg.production('expression : DATA_FLOAT')
-        def exp_int(tokens):
+        def exp_float(tokens):
             return ast_nodes.ExpInt(float(tokens[0].value))
 
         @self.pg.production('expression : DATA_STRING')

tests/02_variable.plthy

@@ -1,4 +1,4 @@
 hello|
-$2 -> x|
+set 2 -> x|
 do print<variable x;>|
 goodbye|

tests/03_math.plthy

@@ -1,10 +1,10 @@
 hello|
-$1 -> x|
-$2 -> y|
-$5 -> z|
-$variable x+variable y -> z| // 3
-$5-variable z -> z| // 2
-$2*variable z -> x| // 4
-$variable x/variable y -> y| // 2
+set 1 -> x|
+set 2 -> y|
+set 5 -> z|
+set variable x+variable y -> z| // 3
+set 5-variable z -> z| // 2
+set 2*variable z -> x| // 4
+set variable x/variable y -> y| // 2
 do print<variable x;variable y;variable z;>|
 goodbye|

tests/04_scope.plthy

@@ -1,6 +1,6 @@
 hello|
 [
-    $5 -> x|
+    set 5 -> x|
     do print<variable x;>|
 ]|
 goodbye|

tests/05_maybe.plthy

@@ -1,5 +1,5 @@
 hello|
-$1 -> x|
-maybe $variable x + 1 -> x|
+set 1 -> x|
+maybe set variable x + 1 -> x|
 do print<variable x;>|
 goodbye|

tests/06_if.plthy

@@ -1,5 +1,5 @@
 hello|
-$2 -> x|
+set 2 -> x|
 do print<'a';> if variable x = 1|
 do print<'b';> if variable x = 2|
 goodbye|

tests/08_precedence.plthy

@@ -1,8 +1,8 @@
 hello|
-$ 1 + 2 * 3 -> x|
+set  1 + 2 * 3 -> x|
 do print<variable x;>|
-$ 5 -> y if variable x = 7|
+set  5 -> y if variable x = 7|
 do print<variable y;>|
-$$5 -> z + 1 -> a|
+set set 5 -> z + 1 -> a|
 do print<variable z; variable a;>|
 goodbye|

tests/10_E001.plthy

@@ -1,2 +1,2 @@
-$2 -> x|
+set 2 -> x|
 goodbye|

tests/11_E002.plthy

@@ -1,2 +1,2 @@
 hello|
-$2 -> x|
+set 2 -> x|

tests/12_list.plthy

@@ -1,6 +1,6 @@
 hello|
-${1;2;3;} -> x|
+set {1;2;3;} -> x|
 do print<variable x;>|
-${1;1+1;do print<3;>;} -> y|
+set {1;1+1;do print<3;>;} -> y|
 do print<variable y{5 - 4};>|
 goodbye|

tests/13_because.expected

@@ -0,0 +1 @@
+3

tests/13_because.plthy

@@ -0,0 +1,5 @@
+hello|
+set 2 -> x|
+set 3 -> x because variable x = 2|
+do print<variable x;>|
+goodbye|

tests/14_E005-random.expected

@@ -0,0 +1 @@
+E005: Wrong number of arguments for builtin 'random' (1) at line 2

tests/14_E005-random.plthy

@@ -0,0 +1,3 @@
+hello|
+do random<2;>|
+goodbye|

tests/15_C001.expected

@@ -0,0 +1 @@
+C001: Because assertion incorrect

tests/15_C001.plthy

@@ -0,0 +1,5 @@
+hello|
+set 2 -> x|
+set 3 -> x because variable x = 3|
+do print<variable x;>|
+goodbye|