fix: add error for non-default args following default args

bolt/parse.py

@@ -1039,6 +1039,7 @@ def parse_function_signature(stream: TokenStream) -> AstFunctionSignature:
     new_locals: Set[str] = set()
 
     encountered_positional = False
+    encountered_default = False
     encountered_variadic = False
     encountered_variadic_keyword = False
     expect_named_argument = False
@@ -1077,10 +1078,16 @@ def parse_function_signature(stream: TokenStream) -> AstFunctionSignature:
 
                     default = None
                     if stream.get("equal"):
+                        encountered_default = True
                         with stream.provide(
                             identifiers=scoped_identifiers | new_locals
                         ):
                             default = delegate("bolt:expression", stream)
+                    elif encountered_default:
+                        exc = InvalidSyntax(
+                            "Argument without default can not appear after arguments with default values."
+                        )
+                        raise set_location(exc, token)
 
                     argument = AstFunctionSignatureArgument(
                         name=name.value,

examples/bolt_function_signature/beet.yml

@@ -2,6 +2,6 @@ require:
   - bolt
 data_pack:
   load:
-    data/demo/functions/foo: "foo.mcfunction"
+    data/demo/functions/foo.mcfunction: "foo.mcfunction"
 pipeline:
   - mecha

examples/bolt_function_signature/foo.mcfunction

@@ -13,7 +13,7 @@ def f(a=1,):
 def f(a=1, /):
     pass
 
-def f(a=1, /, b):
+def f(a, /, b):
     pass
 
 def f(a=1, /, b=2):
@@ -22,7 +22,7 @@ def f(a=1, /, b=2):
 def f(a=1, /, b=2, *args):
     pass
 
-def f(a=1, /, b=2, *, c):
+def f(a, /, b, *, c):
     pass
 
 def f(a=1, /, b=2, *, c=3):

tests/resources/bolt_examples.mcfunction

@@ -1056,7 +1056,7 @@ def f(a=1,):
 def f(a=1, /):
     pass
 ###
-def f(a=1, /, b):
+def f(a, /, b):
     pass
 ###
 def f(a=1, /, b=2):
@@ -1065,7 +1065,7 @@ def f(a=1, /, b=2):
 def f(a=1, /, b=2, *args):
     pass
 ###
-def f(a=1, /, b=2, *, c):
+def f(a, /, b, *, c):
     pass
 ###
 def f(a=1, /, b=2, *, c=3):
@@ -1103,3 +1103,6 @@ def g(foo, /, bar, /):
 ###
 def g(foo, *args, bar, *args):
     pass
+###
+def g(a=1, b):
+    pass

tests/snapshots/bolt__parse_288__0.txt

@@ -1,46 +1,42 @@
-def f(a=1, /, b):
+def f(a, /, b):
     pass
 ---
 <class 'mecha.ast.AstRoot'>
   location: SourceLocation(pos=0, lineno=1, colno=1)
-  end_location: SourceLocation(pos=26, lineno=2, colno=9)
+  end_location: SourceLocation(pos=24, lineno=2, colno=9)
   commands:
     <class 'mecha.ast.AstCommand'>
       location: SourceLocation(pos=0, lineno=1, colno=1)
-      end_location: SourceLocation(pos=26, lineno=2, colno=9)
+      end_location: SourceLocation(pos=24, lineno=2, colno=9)
       identifier: 'def:function:body'
       arguments:
         <class 'bolt.ast.AstFunctionSignature'>
           location: SourceLocation(pos=4, lineno=1, colno=5)
-          end_location: SourceLocation(pos=16, lineno=1, colno=17)
+          end_location: SourceLocation(pos=14, lineno=1, colno=15)
           decorators:
             <empty>
           name: 'f'
           arguments:
             <class 'bolt.ast.AstFunctionSignatureArgument'>
               location: SourceLocation(pos=6, lineno=1, colno=7)
-              end_location: SourceLocation(pos=9, lineno=1, colno=10)
+              end_location: SourceLocation(pos=7, lineno=1, colno=8)
               name: 'a'
-              default:
-                <class 'bolt.ast.AstValue'>
-                  location: SourceLocation(pos=8, lineno=1, colno=9)
-                  end_location: SourceLocation(pos=9, lineno=1, colno=10)
-                  value: 1
+              default: None
             <class 'bolt.ast.AstFunctionSignaturePositionalMarker'>
-              location: SourceLocation(pos=11, lineno=1, colno=12)
-              end_location: SourceLocation(pos=12, lineno=1, colno=13)
+              location: SourceLocation(pos=9, lineno=1, colno=10)
+              end_location: SourceLocation(pos=10, lineno=1, colno=11)
             <class 'bolt.ast.AstFunctionSignatureArgument'>
-              location: SourceLocation(pos=14, lineno=1, colno=15)
-              end_location: SourceLocation(pos=15, lineno=1, colno=16)
+              location: SourceLocation(pos=12, lineno=1, colno=13)
+              end_location: SourceLocation(pos=13, lineno=1, colno=14)
               name: 'b'
               default: None
         <class 'mecha.ast.AstRoot'>
-          location: SourceLocation(pos=22, lineno=2, colno=5)
-          end_location: SourceLocation(pos=26, lineno=2, colno=9)
+          location: SourceLocation(pos=20, lineno=2, colno=5)
+          end_location: SourceLocation(pos=24, lineno=2, colno=9)
           commands:
             <class 'mecha.ast.AstCommand'>
-              location: SourceLocation(pos=22, lineno=2, colno=5)
-              end_location: SourceLocation(pos=26, lineno=2, colno=9)
+              location: SourceLocation(pos=20, lineno=2, colno=5)
+              end_location: SourceLocation(pos=24, lineno=2, colno=9)
               identifier: 'pass'
               arguments:
                 <empty>

tests/snapshots/bolt__parse_288__1.txt

@@ -1,12 +1,8 @@
 _bolt_lineno = [1], [1]
-_bolt_helper_missing = _bolt_runtime.helpers['missing']
 _bolt_helper_children = _bolt_runtime.helpers['children']
 _bolt_helper_replace = _bolt_runtime.helpers['replace']
 with _bolt_runtime.scope() as _bolt_var0:
-    def f(a=_bolt_helper_missing, /, b):
-        if a is _bolt_helper_missing:
-            _bolt_var0 = 1
-            a = _bolt_var0
+    def f(a, /, b):
         pass
 _bolt_var1 = _bolt_helper_replace(_bolt_refs[0], commands=_bolt_helper_children(_bolt_var0))
 ---
@@ -15,6 +11,6 @@ output = _bolt_var1
 _bolt_refs[0]
 <class 'mecha.ast.AstRoot'>
   location: SourceLocation(pos=0, lineno=1, colno=1)
-  end_location: SourceLocation(pos=26, lineno=2, colno=9)
+  end_location: SourceLocation(pos=24, lineno=2, colno=9)
   commands:
     <class 'mecha.ast.AstCommand'>

tests/snapshots/bolt__parse_291__0.txt

@@ -1,58 +1,50 @@
-def f(a=1, /, b=2, *, c):
+def f(a, /, b, *, c):
     pass
 ---
 <class 'mecha.ast.AstRoot'>
   location: SourceLocation(pos=0, lineno=1, colno=1)
-  end_location: SourceLocation(pos=34, lineno=2, colno=9)
+  end_location: SourceLocation(pos=30, lineno=2, colno=9)
   commands:
     <class 'mecha.ast.AstCommand'>
       location: SourceLocation(pos=0, lineno=1, colno=1)
-      end_location: SourceLocation(pos=34, lineno=2, colno=9)
+      end_location: SourceLocation(pos=30, lineno=2, colno=9)
       identifier: 'def:function:body'
       arguments:
         <class 'bolt.ast.AstFunctionSignature'>
           location: SourceLocation(pos=4, lineno=1, colno=5)
-          end_location: SourceLocation(pos=24, lineno=1, colno=25)
+          end_location: SourceLocation(pos=20, lineno=1, colno=21)
           decorators:
             <empty>
           name: 'f'
           arguments:
             <class 'bolt.ast.AstFunctionSignatureArgument'>
               location: SourceLocation(pos=6, lineno=1, colno=7)
-              end_location: SourceLocation(pos=9, lineno=1, colno=10)
+              end_location: SourceLocation(pos=7, lineno=1, colno=8)
               name: 'a'
-              default:
-                <class 'bolt.ast.AstValue'>
-                  location: SourceLocation(pos=8, lineno=1, colno=9)
-                  end_location: SourceLocation(pos=9, lineno=1, colno=10)
-                  value: 1
+              default: None
             <class 'bolt.ast.AstFunctionSignaturePositionalMarker'>
-              location: SourceLocation(pos=11, lineno=1, colno=12)
-              end_location: SourceLocation(pos=12, lineno=1, colno=13)
+              location: SourceLocation(pos=9, lineno=1, colno=10)
+              end_location: SourceLocation(pos=10, lineno=1, colno=11)
             <class 'bolt.ast.AstFunctionSignatureArgument'>
-              location: SourceLocation(pos=14, lineno=1, colno=15)
-              end_location: SourceLocation(pos=17, lineno=1, colno=18)
+              location: SourceLocation(pos=12, lineno=1, colno=13)
+              end_location: SourceLocation(pos=13, lineno=1, colno=14)
               name: 'b'
-              default:
-                <class 'bolt.ast.AstValue'>
-                  location: SourceLocation(pos=16, lineno=1, colno=17)
-                  end_location: SourceLocation(pos=17, lineno=1, colno=18)
-                  value: 2
+              default: None
             <class 'bolt.ast.AstFunctionSignatureVariadicMarker'>
-              location: SourceLocation(pos=19, lineno=1, colno=20)
-              end_location: SourceLocation(pos=20, lineno=1, colno=21)
+              location: SourceLocation(pos=15, lineno=1, colno=16)
+              end_location: SourceLocation(pos=16, lineno=1, colno=17)
             <class 'bolt.ast.AstFunctionSignatureArgument'>
-              location: SourceLocation(pos=22, lineno=1, colno=23)
-              end_location: SourceLocation(pos=23, lineno=1, colno=24)
+              location: SourceLocation(pos=18, lineno=1, colno=19)
+              end_location: SourceLocation(pos=19, lineno=1, colno=20)
               name: 'c'
               default: None
         <class 'mecha.ast.AstRoot'>
-          location: SourceLocation(pos=30, lineno=2, colno=5)
-          end_location: SourceLocation(pos=34, lineno=2, colno=9)
+          location: SourceLocation(pos=26, lineno=2, colno=5)
+          end_location: SourceLocation(pos=30, lineno=2, colno=9)
           commands:
             <class 'mecha.ast.AstCommand'>
-              location: SourceLocation(pos=30, lineno=2, colno=5)
-              end_location: SourceLocation(pos=34, lineno=2, colno=9)
+              location: SourceLocation(pos=26, lineno=2, colno=5)
+              end_location: SourceLocation(pos=30, lineno=2, colno=9)
               identifier: 'pass'
               arguments:
                 <empty>

tests/snapshots/bolt__parse_291__1.txt

@@ -1,15 +1,8 @@
 _bolt_lineno = [1], [1]
-_bolt_helper_missing = _bolt_runtime.helpers['missing']
 _bolt_helper_children = _bolt_runtime.helpers['children']
 _bolt_helper_replace = _bolt_runtime.helpers['replace']
 with _bolt_runtime.scope() as _bolt_var0:
-    def f(a=_bolt_helper_missing, /, b=_bolt_helper_missing, *, c):
-        if a is _bolt_helper_missing:
-            _bolt_var0 = 1
-            a = _bolt_var0
-        if b is _bolt_helper_missing:
-            _bolt_var1 = 2
-            b = _bolt_var1
+    def f(a, /, b, *, c):
         pass
 _bolt_var1 = _bolt_helper_replace(_bolt_refs[0], commands=_bolt_helper_children(_bolt_var0))
 ---
@@ -18,6 +11,6 @@ output = _bolt_var1
 _bolt_refs[0]
 <class 'mecha.ast.AstRoot'>
   location: SourceLocation(pos=0, lineno=1, colno=1)
-  end_location: SourceLocation(pos=34, lineno=2, colno=9)
+  end_location: SourceLocation(pos=30, lineno=2, colno=9)
   commands:
     <class 'mecha.ast.AstCommand'>

tests/snapshots/bolt__parse_304__0.txt

@@ -0,0 +1,7 @@
+#>ERROR  Argument without default can not appear after arguments with default values.
+# line 1, column 12
+#      1 |  def g(a=1, b):
+#        :             ^
+#      2 |      pass
+def g(a=1, b):
+    pass

tests/snapshots/examples__build_bolt_function_signature__0.pack.md

@@ -1,3 +1,22 @@
 # Lectern snapshot
 
-The data pack and resource pack are empty.
+## Data pack
+
+`@data_pack pack.mcmeta`
+
+```json
+{
+  "pack": {
+    "pack_format": 10,
+    "description": ""
+  }
+}
+```
+
+### demo
+
+`@function(strip_final_newline) demo:foo`
+
+```mcfunction
+
+```