improve error readability

src/odm_sharing/private/rules.py

@@ -88,8 +88,8 @@ class ParseError(Exception):
 
 def gen_error(ctx: SchemaCtx, desc: str) -> ParseError:
     '''returns a ParseError'''
-    col = f',{ctx.column}' if ctx.column else ''
-    msg = f'{ctx.filename}({ctx.line_num}{col}): {desc}'
+    col = f', col: {qt(ctx.column)}' if ctx.column else ''
+    msg = f'{ctx.filename}(ln: {ctx.line_num}{col}): {desc}'
     print('Error: ' + msg, file=sys.stderr)
     return ParseError(msg)
 
@@ -117,7 +117,7 @@ def coerce_value(  # type: ignore
 
         def get_expected(type_class) -> str:  # type: ignore
             if type(type_class) is EnumMeta:
-                return fmt_set(list(type_class))
+                return 'one of ' + fmt_set(list(type_class))
             else:
                 return type_class.__name__
 
@@ -185,7 +185,7 @@ def check_required(ctx: SchemaCtx, val: str, mode: RuleMode,
     def check_set(ctx: SchemaCtx, actual: str, expected: Union[set, list]
                   ) -> None:
         if actual not in expected:
-            err(f'got {qt(actual)}, expected {fmt_set(expected)}')
+            err(f'got {qt(actual)}, expected one of {fmt_set(expected)}')
 
     ctx.column = RULE_ID
     if rule.id <= 0:

src/odm_sharing/private/trees.py

@@ -108,7 +108,7 @@ def __init__(self, filename: str) -> None:
 
 
 def gen_error(ctx: Ctx, desc: str) -> ParseError:
-    loc = f'(rule {ctx.rule_id})' if ctx.rule_id else ''
+    loc = f'(id: {ctx.rule_id})' if ctx.rule_id else ''
     msg = f'{ctx.filename}{loc}: {desc}'
     print('Error: ' + msg, file=sys.stderr)
     return ParseError(msg)

src/odm_sharing/private/utils.py

@@ -20,7 +20,7 @@ def not_empty(x: Union[list, set, str]) -> bool:
 def fmt_set(values: Iterable) -> str:
     '''returns a comma-separated string of the items in `values`, surrounded by
     curly-brackets'''
-    items = ','.join(map(qt, values))
+    items = ', '.join(values)
     return f'{{{items}}}'