Merge branch 'completion-improvements' into 'main'

Completion improvements

See merge request GNOME/blueprint-compiler!243

blueprintcompiler/ast_utils.py

@@ -196,6 +196,13 @@ class AstNode:
 
         return None
 
+    def get_child_at(self, idx: int) -> "AstNode":
+        for child in self.children:
+            if idx in child.range:
+                return child.get_child_at(idx)
+
+        return self
+
     def get_semantic_tokens(self) -> T.Iterator[SemanticToken]:
         for child in self.children:
             yield from child.get_semantic_tokens()

blueprintcompiler/completions.py

@@ -21,7 +21,18 @@ import typing as T
 
 from . import annotations, gir, language
 from .ast_utils import AstNode
-from .completions_utils import *
+from .completions_utils import (
+    CompletionContext,
+    CompletionItemKind,
+    CompletionPriority,
+    completer,
+    completers,
+    get_object_id_completions,
+    get_property_completion,
+    get_sort_key,
+    new_statement_patterns,
+)
+from .language.contexts import ValueTypeCtx
 from .language.types import ClassName
 from .lsp_utils import Completion, CompletionItemKind, TextEdit, get_docs_section
 from .parser import SKIP_TOKENS
@@ -38,13 +49,6 @@ def _complete(
     token_idx: int,
     next_token: Token,
 ) -> T.Iterator[Completion]:
-    for child in ast_node.children:
-        if child.group.start <= idx and (
-            idx < child.group.end or (idx == child.group.end and child.incomplete)
-        ):
-            yield from _complete(lsp, child, tokens, idx, token_idx, next_token)
-            return
-
     prev_tokens: T.List[Token] = []
 
     # collect the 5 previous non-skipped tokens
@@ -54,7 +58,7 @@ def _complete(
             prev_tokens.insert(0, token)
         token_idx -= 1
 
-    for completer in ast_node.completers:
+    for completer in completers:
         yield from completer(prev_tokens, next_token, ast_node, lsp, idx)
 
 
@@ -76,11 +80,25 @@ def complete(
         next_token = tokens[next_token_idx]
 
     # if the current token is an identifier or whitespace, move to the token before it
-    while tokens[token_idx].type in [TokenType.IDENT, TokenType.WHITESPACE]:
+    if tokens[token_idx].type == TokenType.IDENT:
         idx = tokens[token_idx].start
         token_idx -= 1
 
-    yield from _complete(lsp, ast_node, tokens, idx, token_idx, next_token)
+    while tokens[token_idx].type == TokenType.WHITESPACE:
+        idx = tokens[token_idx].start
+        token_idx -= 1
+
+    child_node = ast_node.get_child_at(idx)
+    # If the cursor is at the end of a node, completions should be for the next child of the parent, unless the node
+    # is incomplete.
+    while (
+        child_node.range.end == idx
+        and not child_node.incomplete
+        and child_node.parent is not None
+    ):
+        child_node = child_node.parent
+
+    yield from _complete(lsp, child_node, tokens, idx, token_idx, next_token)
 
 
 @completer([language.GtkDirective])
@@ -159,7 +177,13 @@ def _available_namespace_completions(ctx: CompletionContext):
 
 
 @completer(
-    applies_in=[language.UI, language.ObjectContent, language.Template],
+    applies_in=[
+        language.UI,
+        language.ObjectContent,
+        language.Template,
+        language.TypeName,
+        language.BracketedTypeName,
+    ],
     matches=new_statement_patterns,
 )
 def namespace(ctx: CompletionContext):
@@ -180,7 +204,13 @@ def namespace(ctx: CompletionContext):
 
 
 @completer(
-    applies_in=[language.UI, language.ObjectContent, language.Template],
+    applies_in=[
+        language.UI,
+        language.ObjectContent,
+        language.Template,
+        language.TypeName,
+        language.BracketedTypeName,
+    ],
     matches=[
         [(TokenType.IDENT, None), (TokenType.OP, "."), (TokenType.IDENT, None)],
         [(TokenType.IDENT, None), (TokenType.OP, ".")],
@@ -191,7 +221,11 @@ def object_completer(ctx: CompletionContext):
     if ns is not None:
         for c in ns.classes.values():
             snippet = c.name
-            if str(ctx.next_token) != "{":
+            if (
+                str(ctx.next_token) != "{"
+                and not isinstance(ctx.ast_node, language.TypeName)
+                and not isinstance(ctx.ast_node, language.BracketedTypeName)
+            ):
                 snippet += " {\n  $0\n}"
 
             yield Completion(
@@ -205,7 +239,13 @@ def object_completer(ctx: CompletionContext):
 
 
 @completer(
-    applies_in=[language.UI, language.ObjectContent, language.Template],
+    applies_in=[
+        language.UI,
+        language.ObjectContent,
+        language.Template,
+        language.TypeName,
+        language.BracketedTypeName,
+    ],
     matches=new_statement_patterns,
 )
 def gtk_object_completer(ctx: CompletionContext):
@@ -213,7 +253,11 @@ def gtk_object_completer(ctx: CompletionContext):
     if ns is not None:
         for c in ns.classes.values():
             snippet = c.name
-            if str(ctx.next_token) != "{":
+            if (
+                str(ctx.next_token) != "{"
+                and not isinstance(ctx.ast_node, language.TypeName)
+                and not isinstance(ctx.ast_node, language.BracketedTypeName)
+            ):
                 snippet += " {\n  $0\n}"
 
             yield Completion(
@@ -225,6 +269,17 @@ def gtk_object_completer(ctx: CompletionContext):
                 detail=c.detail,
             )
 
+    if isinstance(ctx.ast_node, language.BracketedTypeName) or (
+        isinstance(ctx.ast_node, language.TypeName)
+        and not isinstance(ctx.ast_node, language.ClassName)
+    ):
+        for basic_type in gir.BASIC_TYPES:
+            yield Completion(
+                basic_type,
+                CompletionItemKind.Class,
+                sort_text=get_sort_key(CompletionPriority.CLASS, basic_type),
+            )
+
 
 @completer(
     applies_in=[language.ObjectContent],
@@ -236,7 +291,7 @@ def property_completer(ctx: CompletionContext):
         for prop_name, prop in ctx.ast_node.gir_class.properties.items():
             yield get_property_completion(
                 prop_name,
-                prop,
+                prop.type,
                 ctx,
                 annotations.is_property_translated(prop),
                 prop.doc,
@@ -245,7 +300,11 @@ def property_completer(ctx: CompletionContext):
 
 @completer(
     applies_in=[language.Property, language.A11yProperty],
-    matches=[[(TokenType.IDENT, None), (TokenType.OP, ":")]],
+    matches=[
+        [(TokenType.IDENT, None), (TokenType.OP, ":")],
+        [(TokenType.PUNCTUATION, ",")],
+        [(TokenType.PUNCTUATION, "[")],
+    ],
 )
 def prop_value_completer(ctx: CompletionContext):
     if isinstance(ctx.ast_node, language.Property):
@@ -262,6 +321,8 @@ def prop_value_completer(ctx: CompletionContext):
     )
 
     if (vt := ctx.ast_node.value_type) is not None:
+        assert isinstance(vt, ValueTypeCtx)
+
         if isinstance(vt.value_type, gir.Enumeration):
             for name, member in vt.value_type.members.items():
                 yield Completion(
@@ -287,22 +348,14 @@ def prop_value_completer(ctx: CompletionContext):
         elif isinstance(vt.value_type, gir.Class) or isinstance(
             vt.value_type, gir.Interface
         ):
-            yield Completion(
-                "null",
-                CompletionItemKind.Constant,
-                sort_text=get_sort_key(CompletionPriority.KEYWORD, "null"),
-            )
+            if vt.allow_null:
+                yield Completion(
+                    "null",
+                    CompletionItemKind.Constant,
+                    sort_text=get_sort_key(CompletionPriority.KEYWORD, "null"),
+                )
 
-            for id, obj in ctx.ast_node.root.context[language.ScopeCtx].objects.items():
-                if obj.gir_class is not None and obj.gir_class.assignable_to(
-                    vt.value_type
-                ):
-                    yield Completion(
-                        id,
-                        CompletionItemKind.Variable,
-                        signature=" " + obj.signature,
-                        sort_text=get_sort_key(CompletionPriority.NAMED_OBJECT, id),
-                    )
+            yield from get_object_id_completions(ctx, vt.value_type)
 
             if isinstance(ctx.ast_node, language.Property):
                 yield from _available_namespace_completions(ctx)
@@ -348,7 +401,7 @@ def signal_completer(ctx: CompletionContext):
                         .lower()
                     )
 
-                snippet = f"{signal_name} => \\$${{1:${name}_{signal_name.replace('-', '_')}}}()$0;"
+                snippet = f"{signal_name} => \\$${{1:{name}_{signal_name.replace('-', '_')}}}()$0;"
 
             yield Completion(
                 signal_name,
@@ -367,3 +420,58 @@ def template_completer(_ctx: CompletionContext):
         CompletionItemKind.Snippet,
         snippet="template ${1:ClassName} : ${2:ParentClass} {\n  $0\n}",
     )
+
+
+@completer(
+    applies_in=[language.ObjectContent, language.ChildType],
+    matches=[[(TokenType.PUNCTUATION, "[")]],
+    applies_in_subclass=[("Gtk", "Dialog"), ("Gtk", "InfoBar")],
+)
+def response_id_completer(ctx: CompletionContext):
+    yield Completion(
+        "action",
+        CompletionItemKind.Snippet,
+        sort_text=get_sort_key(CompletionPriority.KEYWORD, "action"),
+        snippet="action response=$0",
+    )
+
+
+@completer(
+    [language.ChildAnnotation, language.ExtResponse],
+    [[(TokenType.IDENT, "action"), (TokenType.IDENT, "response"), (TokenType.OP, "=")]],
+)
+def complete_response_id(ctx: CompletionContext):
+    gir = ctx.ast_node.root.gir
+    response_type = gir.get_type("ResponseType", "Gtk")
+    yield from [
+        Completion(
+            name,
+            kind=CompletionItemKind.EnumMember,
+            docs=member.doc,
+        )
+        for name, member in response_type.members.items()
+    ]
+
+
+@completer(
+    [language.ChildAnnotation, language.ExtResponse],
+    [
+        [
+            (TokenType.IDENT, "action"),
+            (TokenType.IDENT, "response"),
+            (TokenType.OP, "="),
+            (TokenType.IDENT, None),
+        ],
+        [
+            (TokenType.IDENT, "action"),
+            (TokenType.IDENT, "response"),
+            (TokenType.OP, "="),
+            (TokenType.NUMBER, None),
+        ],
+    ],
+)
+def complete_response_default(ctx: CompletionContext):
+    yield Completion(
+        "default",
+        kind=CompletionItemKind.Keyword,
+    )

blueprintcompiler/completions_utils.py

@@ -22,7 +22,7 @@ import typing as T
 from dataclasses import dataclass
 from enum import Enum
 
-from . import gir
+from . import gir, language
 from .ast_utils import AstNode
 from .lsp_utils import Completion, CompletionItemKind
 from .tokenizer import Token, TokenType
@@ -57,21 +57,40 @@ new_statement_patterns = [
     [(TokenType.PUNCTUATION, "}")],
     [(TokenType.PUNCTUATION, "]")],
     [(TokenType.PUNCTUATION, ";")],
+    [(TokenType.OP, "<")],
 ]
 
 
+completers = []
+
+
 def completer(applies_in: T.List, matches: T.List = [], applies_in_subclass=None):
     def decorator(func: T.Callable[[CompletionContext], T.Generator[Completion]]):
         def inner(
             prev_tokens: T.List[Token], next_token: Token, ast_node, lsp, idx: int
         ):
+            if not any(isinstance(ast_node, rule) for rule in applies_in):
+                return
+
             # For completers that apply in ObjectContent nodes, we can further
             # check that the object is the right class
             if applies_in_subclass is not None:
-                type = ast_node.root.gir.get_type(
-                    applies_in_subclass[1], applies_in_subclass[0]
-                )
-                if not ast_node.gir_class or not ast_node.gir_class.assignable_to(type):
+                parent_obj = ast_node
+                while parent_obj is not None and not hasattr(parent_obj, "gir_class"):
+                    parent_obj = parent_obj.parent
+
+                if (
+                    parent_obj is None
+                    or not parent_obj.gir_class
+                    or not any(
+                        [
+                            parent_obj.gir_class.assignable_to(
+                                parent_obj.root.gir.get_type(c[1], c[0])
+                            )
+                            for c in applies_in_subclass
+                        ]
+                    )
+                ):
                     return
 
             any_match = len(matches) == 0
@@ -106,8 +125,7 @@ def completer(applies_in: T.List, matches: T.List = [], applies_in_subclass=None
             )
             yield from func(context)
 
-        for c in applies_in:
-            c.completers.append(inner)
+        completers.append(inner)
         return inner
 
     return decorator
@@ -145,3 +163,18 @@ def get_property_completion(
         snippet=snippet,
         docs=doc,
     )
+
+
+def get_object_id_completions(
+    ctx: CompletionContext, value_type: T.Optional[gir.GirType] = None
+):
+    for id, obj in ctx.ast_node.root.context[language.ScopeCtx].objects.items():
+        if value_type is None or (
+            obj.gir_class is not None and obj.gir_class.assignable_to(value_type)
+        ):
+            yield Completion(
+                id,
+                CompletionItemKind.Variable,
+                signature=" " + obj.signature,
+                sort_text=get_sort_key(CompletionPriority.NAMED_OBJECT, id),
+            )

blueprintcompiler/errors.py

@@ -92,29 +92,38 @@ class CompileError(PrintableError):
     def pretty_print(self, filename: str, code: str, stream=sys.stdout) -> None:
         assert self.range is not None
 
-        line_num, col_num = utils.idx_to_pos(self.range.start + 1, code)
-        end_line_num, end_col_num = utils.idx_to_pos(self.range.end + 1, code)
-        line = code.splitlines(True)[line_num] if code != "" else ""
+        def format_line(range: Range):
+            line_num, col_num = utils.idx_to_pos(range.start, code)
+            end_line_num, end_col_num = utils.idx_to_pos(range.end, code)
+            line = code.splitlines(True)[line_num] if code != "" else ""
 
-        # Display 1-based line numbers
-        line_num += 1
-        end_line_num += 1
+            # Display 1-based line numbers
+            line_num += 1
+            end_line_num += 1
+            col_num += 1
+            end_col_num += 1
 
-        n_spaces = col_num - 1
-        n_carets = (
-            (end_col_num - col_num)
-            if line_num == end_line_num
-            else (len(line) - n_spaces - 1)
-        )
+            n_spaces = col_num - 1
+            n_carets = (
+                (end_col_num - col_num)
+                if line_num == end_line_num
+                else (len(line) - n_spaces - 1)
+            )
 
-        n_spaces += line.count("\t", 0, col_num)
-        n_carets += line.count("\t", col_num, col_num + n_carets)
-        line = line.replace("\t", "  ")
+            n_spaces += line.count("\t", 0, col_num)
+            n_carets += line.count("\t", col_num, col_num + n_carets)
+            line = line.replace("\t", "  ")
+
+            n_carets = max(n_carets, 1)
+
+            return line_num, col_num, line.rstrip(), (" " * n_spaces) + ("^" * n_carets)
+
+        line_num, col_num, line, carets = format_line(self.range)
 
         stream.write(
             f"""{self.color}{Colors.BOLD}{self.category}: {self.message}{Colors.CLEAR}
 at {filename} line {line_num} column {col_num}:
-{Colors.FAINT}{line_num :>4} |{Colors.CLEAR}{line.rstrip()}\n     {Colors.FAINT}|{" "*n_spaces}{"^"*n_carets}{Colors.CLEAR}\n"""
+{Colors.FAINT}{line_num :>4} |{Colors.CLEAR}{line}\n     {Colors.FAINT}|{carets}{Colors.CLEAR}\n"""
         )
 
         for hint in self.hints:
@@ -139,14 +148,12 @@ at {filename} line {line_num} column {col_num}:
                 )
 
         for ref in self.references:
-            line_num, col_num = utils.idx_to_pos(ref.range.start + 1, code)
-            line = code.splitlines(True)[line_num]
-            line_num += 1
+            line_num, col_num, line, carets = format_line(ref.range)
 
             stream.write(
                 f"""{Colors.FAINT}note: {ref.message}:
 at {filename} line {line_num} column {col_num}:
-{Colors.FAINT}{line_num :>4} |{line.rstrip()}\n     {Colors.FAINT}|{" "*(col_num-1)}^{Colors.CLEAR}\n"""
+{Colors.FAINT}{line_num :>4} |{line}\n     {Colors.FAINT}|{carets}{Colors.CLEAR}\n"""
             )
 
         stream.write("\n")

blueprintcompiler/gir.py

@@ -289,7 +289,7 @@ class TypeType(BasicType):
         return isinstance(other, TypeType)
 
 
-_BASIC_TYPES = {
+BASIC_TYPES = {
     "bool": BoolType,
     "string": StringType,
     "int": IntType,
@@ -914,7 +914,7 @@ class Namespace(GirNode):
 
     def get_type_by_cname(self, cname: str) -> T.Optional[GirType]:
         """Gets a type from this namespace by its C name."""
-        for basic in _BASIC_TYPES.values():
+        for basic in BASIC_TYPES.values():
             if basic.glib_type_name == cname:
                 return basic()
 
@@ -1036,8 +1036,8 @@ class GirContext:
         return None
 
     def get_type(self, name: str, ns: str) -> T.Optional[GirType]:
-        if ns is None and name in _BASIC_TYPES:
-            return _BASIC_TYPES[name]()
+        if ns is None and name in BASIC_TYPES:
+            return BASIC_TYPES[name]()
 
         ns = ns or "Gtk"
 

blueprintcompiler/language/__init__.py

@@ -34,10 +34,17 @@ from .gtk_scale import ExtScaleMarks
 from .gtk_size_group import ExtSizeGroupWidgets
 from .gtk_string_list import ExtStringListStrings
 from .gtk_styles import ExtStyles
-from .gtkbuilder_child import Child, ChildExtension, ChildInternal, ChildType
+from .gtkbuilder_child import (
+    Child,
+    ChildAnnotation,
+    ChildExtension,
+    ChildInternal,
+    ChildType,
+)
 from .gtkbuilder_template import Template
 from .imports import GtkDirective, Import
-from .types import ClassName
+from .response_id import ExtResponse
+from .types import BracketedTypeName, ClassName, TypeName
 from .ui import UI
 from .values import (
     ArrayValue,

blueprintcompiler/language/adw_response_dialog.py

@@ -140,7 +140,7 @@ class ExtAdwResponseDialog(AstNode):
 
 @completer(
     applies_in=[ObjectContent],
-    applies_in_subclass=("Adw", "MessageDialog"),
+    applies_in_subclass=[("Adw", "AlertDialog"), ("Adw", "MessageDialog")],
     matches=new_statement_patterns,
 )
 def complete_adw_message_dialog(_ctx: CompletionContext):
@@ -149,20 +149,6 @@ def complete_adw_message_dialog(_ctx: CompletionContext):
     )
 
 
-@completer(
-    applies_in=[ObjectContent],
-    applies_in_subclass=("Adw", "AlertDialog"),
-    matches=new_statement_patterns,
-)
-def complete_adw_alert_dialog(_ctx: CompletionContext):
-    yield Completion(
-        "responses",
-        CompletionItemKind.Keyword,
-        snippet="responses [\n\t$0\n]",
-        sort_text=get_sort_key(CompletionPriority.OBJECT_MEMBER, "responses"),
-    )
-
-
 @decompiler("responses")
 def decompile_responses(ctx, gir):
     ctx.print(f"responses [")

blueprintcompiler/language/common.py

@@ -34,6 +34,7 @@ from ..errors import (
     CompileError,
     CompileWarning,
     DeprecatedWarning,
+    ErrorReference,
     MultipleErrors,
     UnusedWarning,
     UpgradeWarning,

blueprintcompiler/language/contexts.py

@@ -48,7 +48,7 @@ class ScopeCtx:
             return self.node
 
     @cached_property
-    def objects(self) -> T.Dict[str, Object]:
+    def objects(self) -> T.Dict[str, AstNode]:
         return {
             obj.tokens["id"]: obj
             for obj in self._iter_recursive(self.node)
@@ -58,7 +58,7 @@ class ScopeCtx:
     def validate_unique_ids(self) -> None:
         from .gtk_list_item_factory import ExtListItemFactory
 
-        passed = {}
+        passed: T.Dict[str, AstNode] = {}
         for obj in self._iter_recursive(self.node):
             if obj.tokens["id"] is None:
                 continue
@@ -71,10 +71,16 @@ class ScopeCtx:
                     raise CompileError(
                         f"Duplicate object ID '{obj.tokens['id']}'",
                         token.range,
+                        references=[
+                            ErrorReference(
+                                passed[obj.tokens["id"]].group.tokens["id"].range,
+                                "previous declaration was here",
+                            )
+                        ],
                     )
             passed[obj.tokens["id"]] = obj
 
-    def _iter_recursive(self, node: AstNode):
+    def _iter_recursive(self, node: AstNode) -> T.Generator[AstNode, T.Any, None]:
         yield node
         for child in node.children:
             if child.context[ScopeCtx] is self:

blueprintcompiler/language/expression.py

@@ -21,7 +21,7 @@
 from ..decompiler import decompile_element
 from .common import *
 from .contexts import ScopeCtx, ValueTypeCtx
-from .types import TypeName
+from .types import BracketedTypeName, TypeName
 
 expr = Sequence()
 
@@ -196,7 +196,7 @@ class CastExpr(InfixExpr):
     grammar = [
         Keyword("as"),
         AnyOf(
-            ["<", TypeName, Match(">").expected()],
+            BracketedTypeName,
             [
                 UseExact("lparen", "("),
                 TypeName,
@@ -211,7 +211,13 @@ class CastExpr(InfixExpr):
 
     @property
     def type(self) -> T.Optional[GirType]:
-        return self.children[TypeName][0].gir_type
+        if len(self.children[BracketedTypeName]) == 1:
+            type_name = self.children[BracketedTypeName][0].type_name
+            return None if type_name is None else type_name.gir_type
+        elif len(self.children[TypeName]) == 1:
+            return self.children[TypeName][0].gir_type
+        else:
+            return None
 
     @validate()
     def cast_makes_sense(self):

blueprintcompiler/language/gobject_signal.py

@@ -247,3 +247,11 @@ def decompile_signal(
     line += ";"
     ctx.print(line)
     return gir
+
+
+@completer(
+    [Signal],
+    [[(TokenType.PUNCTUATION, "(")]],
+)
+def signal_object_completer(ctx: CompletionContext):
+    yield from get_object_id_completions(ctx)

blueprintcompiler/language/gtk_combo_box_text.py

@@ -91,7 +91,7 @@ class ExtComboBoxItems(AstNode):
 
 @completer(
     applies_in=[ObjectContent],
-    applies_in_subclass=("Gtk", "ComboBoxText"),
+    applies_in_subclass=[("Gtk", "ComboBoxText")],
     matches=new_statement_patterns,
 )
 def items_completer(_ctx: CompletionContext):

blueprintcompiler/language/gtk_file_filter.py

@@ -98,7 +98,7 @@ ext_file_filter_suffixes = create_node("suffixes", "suffix")
 
 @completer(
     applies_in=[ObjectContent],
-    applies_in_subclass=("Gtk", "FileFilter"),
+    applies_in_subclass=[("Gtk", "FileFilter")],
     matches=new_statement_patterns,
 )
 def file_filter_completer(_ctx: CompletionContext):

blueprintcompiler/language/gtk_layout.py

@@ -90,7 +90,7 @@ class ExtLayout(AstNode):
 
 @completer(
     applies_in=[ObjectContent],
-    applies_in_subclass=("Gtk", "Widget"),
+    applies_in_subclass=[("Gtk", "Widget")],
     matches=new_statement_patterns,
 )
 def layout_completer(_ctx: CompletionContext):

blueprintcompiler/language/gtk_scale.py

@@ -23,22 +23,20 @@ from .values import StringValue
 
 
 class ExtScaleMark(AstNode):
-    grammar = [
+    grammar = Statement(
         Keyword("mark"),
         Match("(").expected(),
-        [
-            Optional(AnyOf(UseExact("sign", "-"), UseExact("sign", "+"))),
-            UseNumber("value"),
-            Optional(
-                [
-                    ",",
-                    UseIdent("position"),
-                    Optional([",", StringValue]),
-                ]
-            ),
-        ],
-        Match(")").expected(),
-    ]
+        Optional(AnyOf(UseExact("sign", "-"), UseExact("sign", "+"))),
+        UseNumber("value").expected("value"),
+        Optional(
+            [
+                ",",
+                UseIdent("position").expected("position"),
+                Optional([",", to_parse_node(StringValue).expected("label")]),
+            ]
+        ),
+        end=")",
+    )
 
     @property
     def value(self) -> float:
@@ -134,7 +132,7 @@ class ExtScaleMarks(AstNode):
 
 @completer(
     applies_in=[ObjectContent],
-    applies_in_subclass=("Gtk", "Scale"),
+    applies_in_subclass=[("Gtk", "Scale")],
     matches=new_statement_patterns,
 )
 def complete_marks(_ctx: CompletionContext):
@@ -153,6 +151,23 @@ def complete_mark(_ctx: CompletionContext):
     yield Completion("mark", CompletionItemKind.Keyword, snippet="mark ($0),")
 
 
+@completer(
+    applies_in=[ExtScaleMark],
+    matches=[[(TokenType.NUMBER, None), (TokenType.PUNCTUATION, ",")]],
+)
+def complete_mark_position(ctx: CompletionContext):
+    gir = ctx.ast_node.root.gir
+    response_type = gir.get_type("PositionType", "Gtk")
+    yield from [
+        Completion(
+            name,
+            kind=CompletionItemKind.EnumMember,
+            docs=member.doc,
+        )
+        for name, member in response_type.members.items()
+    ]
+
+
 @decompiler("marks")
 def decompile_marks(
     ctx,

blueprintcompiler/language/gtk_size_group.py

@@ -101,7 +101,7 @@ class ExtSizeGroupWidgets(AstNode):
 
 @completer(
     applies_in=[ObjectContent],
-    applies_in_subclass=("Gtk", "SizeGroup"),
+    applies_in_subclass=[("Gtk", "SizeGroup")],
     matches=new_statement_patterns,
 )
 def size_group_completer(_ctx: CompletionContext):

blueprintcompiler/language/gtk_string_list.py

@@ -72,7 +72,7 @@ class ExtStringListStrings(AstNode):
 
 @completer(
     applies_in=[ObjectContent],
-    applies_in_subclass=("Gtk", "StringList"),
+    applies_in_subclass=[("Gtk", "StringList")],
     matches=new_statement_patterns,
 )
 def strings_completer(_ctx: CompletionContext):

blueprintcompiler/language/gtk_styles.py

@@ -77,7 +77,7 @@ class ExtStyles(AstNode):
 
 @completer(
     applies_in=[ObjectContent],
-    applies_in_subclass=("Gtk", "Widget"),
+    applies_in_subclass=[("Gtk", "Widget")],
     matches=new_statement_patterns,
 )
 def style_completer(_ctx: CompletionContext):

blueprintcompiler/language/gtkbuilder_child.py

@@ -31,7 +31,12 @@ ALLOWED_PARENTS: T.List[T.Tuple[str, str]] = [
 
 
 class ChildInternal(AstNode):
-    grammar = ["internal-child", UseIdent("internal_child")]
+    grammar = [
+        "[",
+        "internal-child",
+        UseIdent("internal_child").expected("internal child name"),
+        Match("]").expected(),
+    ]
 
     @property
     def internal_child(self) -> str:
@@ -39,7 +44,7 @@ class ChildInternal(AstNode):
 
 
 class ChildType(AstNode):
-    grammar = UseIdent("child_type").expected("a child type")
+    grammar = ["[", UseIdent("child_type").expected("a child type"), "]"]
 
     @property
     def child_type(self) -> str:
@@ -59,7 +64,7 @@ class ChildExtension(AstNode):
 
 
 class ChildAnnotation(AstNode):
-    grammar = ["[", AnyOf(ChildInternal, ChildExtension, ChildType), "]"]
+    grammar = AnyOf(ChildInternal, ChildExtension, ChildType)
 
     @property
     def child(self) -> T.Union[ChildInternal, ChildExtension, ChildType]:

blueprintcompiler/language/response_id.py

@@ -28,19 +28,21 @@ class ExtResponse(AstNode):
 
     ALLOWED_PARENTS: T.List[T.Tuple[str, str]] = [("Gtk", "Dialog"), ("Gtk", "InfoBar")]
 
-    grammar = [
+    grammar = Statement(
+        "[",
         Keyword("action"),
         Keyword("response"),
-        "=",
+        Match("=").expected(),
         AnyOf(
             UseIdent("response_id"),
             [
                 Optional(UseExact("sign", "-")),
                 UseNumber("response_id"),
             ],
-        ),
+        ).expected("response ID"),
         Optional([Keyword("default"), UseLiteral("is_default", True)]),
-    ]
+        end="]",
+    )
 
     @validate()
     def parent_has_action_widgets(self) -> None:

blueprintcompiler/language/types.py

@@ -27,11 +27,11 @@ class TypeName(AstNode):
         [
             UseIdent("namespace"),
             ".",
-            UseIdent("class_name"),
+            UseIdent("class_name").expected("class name"),
         ],
         [
             AnyOf("$", [".", UseLiteral("old_extern", True)]),
-            UseIdent("class_name"),
+            UseIdent("class_name").expected("class name"),
             UseLiteral("extern", True),
         ],
         UseIdent("class_name"),
@@ -47,7 +47,11 @@ class TypeName(AstNode):
 
     @validate("class_name")
     def type_exists(self):
-        if not self.tokens["extern"] and self.gir_ns is not None:
+        if (
+            not self.tokens["extern"]
+            and self.gir_ns is not None
+            and self.tokens["class_name"] is not None
+        ):
             self.root.gir.validate_type(
                 self.tokens["class_name"], self.tokens["namespace"]
             )
@@ -182,3 +186,14 @@ class TemplateClassName(ClassName):
             self.root.gir.validate_type(
                 self.tokens["class_name"], self.tokens["namespace"]
             )
+
+
+class BracketedTypeName(AstNode):
+    grammar = Statement("<", to_parse_node(TypeName).expected("type name"), end=">")
+
+    @property
+    def type_name(self) -> T.Optional[TypeName]:
+        if len(self.children[TypeName]) == 0:
+            return None
+
+        return self.children[TypeName][0]

blueprintcompiler/language/values.py

@@ -26,7 +26,7 @@ from .common import *
 from .contexts import ExprValueCtx, ScopeCtx, ValueTypeCtx
 from .expression import Expression
 from .gobject_object import Object
-from .types import TypeName
+from .types import BracketedTypeName, TypeName
 
 
 class Translated(AstNode):
@@ -80,11 +80,7 @@ class TypeLiteral(AstNode):
     grammar = [
         "typeof",
         AnyOf(
-            [
-                "<",
-                to_parse_node(TypeName).expected("type name"),
-                Match(">").expected(),
-            ],
+            BracketedTypeName,
             [
                 UseExact("lparen", "("),
                 to_parse_node(TypeName).expected("type name"),
@@ -98,8 +94,13 @@ class TypeLiteral(AstNode):
         return gir.TypeType()
 
     @property
-    def type_name(self) -> TypeName:
-        return self.children[TypeName][0]
+    def type_name(self) -> T.Optional[TypeName]:
+        if len(self.children[BracketedTypeName]) == 1:
+            return self.children[BracketedTypeName][0].type_name
+        elif len(self.children[TypeName]) == 1:
+            return self.children[TypeName][0]
+        else:
+            return None
 
     @validate()
     def validate_for_type(self) -> None:

blueprintcompiler/outputs/xml/__init__.py

@@ -209,6 +209,7 @@ class XmlOutput(OutputFormat):
             else:
                 xml.put_text(self._object_id(value, value.ident))
         elif isinstance(value, TypeLiteral):
+            assert value.type_name is not None
             xml.put_text(value.type_name.glib_type_name)
         else:
             if isinstance(value.value, float) and value.value == int(value.value):

blueprintcompiler/parse_tree.py

@@ -235,7 +235,15 @@ class ParseNode:
         start_idx = ctx.index
         inner_ctx = ctx.create_child()
 
-        if self._parse(inner_ctx):
+        try:
+            result = self._parse(inner_ctx)
+        except Exception as e:
+            # If an exception occurs, there's an explicit error, not just a rule that didn't match. Apply the context
+            # state so that whichever rule handles the exception (e.g. a Statement) knows where the error occurred.
+            ctx.apply_child(inner_ctx)
+            raise e
+
+        if result:
             ctx.apply_child(inner_ctx)
             if ctx.index == start_idx:
                 return ParseResult.EMPTY
@@ -269,12 +277,12 @@ class Err(ParseNode):
         if self.child.parse(ctx).failed():
             start_idx = ctx.start
             while ctx.tokens[start_idx].type in SKIP_TOKENS:
-                start_idx += 1
+                start_idx -= 1
             start_token = ctx.tokens[start_idx]
 
-            raise CompileError(
-                self.message, Range(start_token.start, start_token.start, ctx.text)
-            )
+            position = start_token.start if ctx.start == start_idx else start_token.end
+
+            raise CompileError(self.message, Range(position, position, ctx.text))
         return True
 
 
@@ -329,8 +337,9 @@ class Statement(ParseNode):
     """ParseNode that attempts to match all of its children in sequence. If any
     child raises an error, the error will be logged but parsing will continue."""
 
-    def __init__(self, *children):
+    def __init__(self, *children, end: str = ";"):
         self.children = [to_parse_node(child) for child in children]
+        self.end = end
 
     def _parse(self, ctx) -> bool:
         for child in self.children:
@@ -340,11 +349,29 @@ class Statement(ParseNode):
             except CompileError as e:
                 ctx.errors.append(e)
                 ctx.set_group_incomplete()
+
+                token = ctx.peek_token()
+                if str(token) == self.end:
+                    ctx.next_token()
+
                 return True
 
         token = ctx.peek_token()
-        if str(token) != ";":
-            ctx.errors.append(CompileError("Expected `;`", token.range))
+        if str(token) != self.end:
+            start_idx = ctx.index - 1
+            while ctx.tokens[start_idx].type in SKIP_TOKENS:
+                start_idx -= 1
+            start_token = ctx.tokens[start_idx]
+
+            position = (
+                start_token.start if ctx.index - 1 == start_idx else start_token.end
+            )
+
+            ctx.errors.append(
+                CompileError(
+                    f"Expected `{self.end}`", Range(position, position, ctx.text)
+                )
+            )
         else:
             ctx.next_token()
         return True
@@ -405,7 +432,6 @@ class Until(ParseNode):
                         ctx.skip_unexpected_token()
             except CompileError as e:
                 ctx.errors.append(e)
-                ctx.next_token()
 
         return True
 

tests/sample_errors/action_widget_have_no_id.err

@@ -1 +1 @@
-4,6,22,Action widget must have ID
+4,5,24,Action widget must have ID

tests/sample_errors/action_widget_in_invalid_container.err

@@ -1 +1 @@
-4,6,18,Gtk.Box doesn't have action widgets
+4,5,20,Gtk.Box doesn't have action widgets

tests/sample_errors/empty.err

@@ -1 +1 @@
-1,0,0,File must start with a "using Gtk" directive (e.g. `using Gtk 4.0;`)
+1,1,0,File must start with a "using Gtk" directive (e.g. `using Gtk 4.0;`)

tests/sample_errors/expected_semicolon.err

@@ -1 +1 @@
-6,1,1,Expected `;`
+5,4,0,Expected `;`

tests/sample_errors/incomplete_signal.err

@@ -1,2 +1 @@
-5,1,0,Expected a signal detail name
-4,9,3,Unexpected tokens
+4,11,0,Expected a signal detail name

tests/sample_errors/menu_toplevel_attribute.err

@@ -1,2 +1 @@
-4,5,21,Attributes are not permitted at the top level of a menu
-4,16,10,Unexpected tokens
+4,5,21,Attributes are not permitted at the top level of a menu

tests/sample_errors/no_import_version.err

@@ -1 +1 @@
-1,11,0,Expected a version number for GTK
+1,10,0,Expected a version number for GTK

tests/test_samples.py

@@ -143,9 +143,9 @@ class TestSamples(unittest.TestCase):
             ]
 
             def error_str(error: CompileError):
-                line, col = utils.idx_to_pos(error.range.start + 1, blueprint)
+                line, col = utils.idx_to_pos(error.range.start, blueprint)
                 len = error.range.length
-                return ",".join([str(line + 1), str(col), str(len), error.message])
+                return ",".join([str(line + 1), str(col + 1), str(len), error.message])
 
             actual = "\n".join([error_str(error) for error in errors])