feat: .Warning added to Error_Kind.

TODOS.md

@@ -1,5 +1,10 @@
 # TODOs
 
+## Priority Unclear (Evaluate Later)
+
+- [ ] instead of `warnings: [dynamic]Error` we should use `warnings: [dynamic; 8]Error`
+  - when limit reached, the template fails and stops rendering.
+
 ## General
 
 Remember to polish existing features before moving on to new ones.

mustache/mustache.odin

@@ -25,6 +25,7 @@ Context_Stack :: [dynamic]any
 Error_Kind :: enum {
 	Syntax,   // parse-time: malformed template
 	Data,     // render-time: template fine, data wrong (e.g. filter misuse)
+	Warning,  // non-fatal: operation succeeded but user should know
 }
 
 Error_Body :: struct {
@@ -176,6 +177,7 @@ render :: proc(
 	data: any,
 	partials: map[string]Template = nil,
 	allocator := context.allocator,
+	warnings: ^[dynamic]Error = nil,
 ) -> (
 	result: string,
 	err: Error,
@@ -201,7 +203,7 @@ render :: proc(
 	}
 
 	all_nodes := tmpl.nodes[:]
-	err = render_nodes(tmpl, all_nodes, &ctx, partials, &builder)
+	err = render_nodes(tmpl, all_nodes, &ctx, partials, &builder, warnings = warnings)
 	if err != nil {
 		return result, err
 	}
@@ -545,6 +547,7 @@ render_template :: proc(
 	b: ^strings.Builder,
 	blocks: map[string]Block_Override,
 	indent: string,
+	warnings: ^[dynamic]Error = nil,
 ) -> Error {
 	if len(indent) > 0 {
 		state := Indent_State {
@@ -552,9 +555,9 @@ render_template :: proc(
 			at_line_start = false,
 		}
 		strings.write_string(b, indent) // first line always gets indent
-		return render_nodes(pt, pt.nodes[:], ctx, partials, b, blocks, &state)
+		return render_nodes(pt, pt.nodes[:], ctx, partials, b, blocks, &state, warnings)
 	}
-	return render_nodes(pt, pt.nodes[:], ctx, partials, b, blocks, nil)
+	return render_nodes(pt, pt.nodes[:], ctx, partials, b, blocks, nil, warnings)
 }
 
 write_indented :: proc(
@@ -598,6 +601,7 @@ render_nodes :: proc(
 	b: ^strings.Builder,
 	blocks: map[string]Block_Override = nil,
 	indent_state: ^Indent_State = nil,
+	warnings: ^[dynamic]Error = nil,
 ) -> Error {
 	i := 0
 	for i < len(nodes) {
@@ -621,7 +625,7 @@ render_nodes :: proc(
 				warn_unknown_key(current, ctx[:], node)
 			}
 			if len(node.filters) > 0 {
-				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:], current)
+				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:], current, warnings)
 				if perr != nil {
 					return tag_error(perr, current)
 				}
@@ -640,7 +644,7 @@ render_nodes :: proc(
 				warn_unknown_key(current, ctx[:], node)
 			}
 			if len(node.filters) > 0 {
-				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:], current)
+				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:], current, warnings)
 				if perr != nil {
 					return tag_error(perr, current)
 				}
@@ -655,7 +659,7 @@ render_nodes :: proc(
 				warn_unknown_key(current, ctx[:], node)
 			}
 			if len(node.filters) > 0 {
-				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:], current)
+				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:], current, warnings)
 				if perr != nil {
 					return tag_error(perr, current)
 				}
@@ -677,6 +681,7 @@ render_nodes :: proc(
 						b,
 						blocks,
 						indent_state,
+						warnings,
 					) or_return
 					}
 				} else {
@@ -690,6 +695,7 @@ render_nodes :: proc(
 						b,
 						blocks,
 						indent_state,
+						warnings,
 					) or_return
 				}
 			}
@@ -701,7 +707,7 @@ render_nodes :: proc(
 				warn_unknown_key(current, ctx[:], node)
 			}
 			if len(node.filters) > 0 {
-				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:], current)
+				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:], current, warnings)
 				if perr != nil {
 					return tag_error(perr, current)
 				}
@@ -716,6 +722,7 @@ render_nodes :: proc(
 				b,
 				blocks,
 				indent_state,
+				warnings,
 			) or_return
 		}
 			i += 1 + len(node.children)
@@ -730,7 +737,7 @@ render_nodes :: proc(
 			if !found {
 				warn_missing_partial(current, partials, node, name)
 			} else {
-				render_template(pt, ctx, partials, b, nil, node.indent) or_return
+				render_template(pt, ctx, partials, b, nil, node.indent, warnings) or_return
 				if indent_state != nil {
 					indent_state.at_line_start = false
 				}
@@ -765,6 +772,7 @@ render_nodes :: proc(
 					&temp,
 					content_blocks,
 					nil,
+					warnings,
 				) or_return
 				at_ls := true
 				write_indented(b, node.indent, strings.to_string(temp), &at_ls)
@@ -777,6 +785,7 @@ render_nodes :: proc(
 					b,
 					content_blocks,
 					indent_state,
+					warnings,
 				) or_return
 			}
 			i += 1 + len(node.children)
@@ -789,7 +798,7 @@ render_nodes :: proc(
 				warn_missing_partial(current, partials, node, node.key)
 			} else {
 				warn_unmatched_block_overrides(current, pt, parent_children)
-				render_template(pt, ctx, partials, b, merged, node.indent) or_return
+				render_template(pt, ctx, partials, b, merged, node.indent, warnings) or_return
 				if indent_state != nil {
 					indent_state.at_line_start = false
 				}

mustache/pipes.odin

@@ -221,14 +221,26 @@ apply_pipeline :: proc(
 	pos: int,
 	ctx: []any,
 	tmpl: Template,
+	warnings: ^[dynamic]Error = nil,
 ) -> (
 	current: any,
 	err: Error,
 ) {
 	current = value
 	for &filter in filters {
-		current = apply_filter(current, &filter, pos, ctx, tmpl) or_return
-		log.debugf("applied: filter=%v before=%s after=%s pos=%d", filter, value, current, pos)
+		result, ferr := apply_filter(current, &filter, pos, ctx, tmpl)
+		if ferr != nil {
+			b := body(ferr)
+			if b.kind != .Warning {
+				return result, ferr
+			}
+			if warnings != nil {
+				append(warnings, ferr)
+			} else {
+				log.warnf("%s", format_render_error(ferr, tmpl))
+			}
+		}
+		current = result
 	}
 	return
 }
@@ -438,6 +450,7 @@ take :: proc(
 	elem_info, count, data := list_info(value)
 	is_list := elem_info != nil
 	from_start := from_start
+	warning: Error = nil
 
 	str: string
 	if !is_list {
@@ -457,15 +470,14 @@ take :: proc(
 
 	n := 1
 	if !is_list && len(args) == 0 {
-		path := tmpl.path != "" ? tmpl.path : "<input>"
-		diag := format_tag_error(
-			path,
-			tmpl.source,
-			op_pos,
-			"defaulting to n=1 for string",
-			"consider specifying n explicitly",
-		)
-		log.warnf("%s", diag)
+		warning = Error_Body {
+			msg = "defaulting to n=1 for string",
+			pos = tag_pos,
+			kind = .Warning,
+			source = tmpl.source,
+			path = tmpl.path,
+			hint = "consider specifying n explicitly",
+		}
 	}
 	if len(args) > 0 {
 		parsed, ok := strconv.parse_int(args[0])
@@ -494,15 +506,14 @@ take :: proc(
 	if n < 0 {
 		op_name := from_start ? "first" : "last"
 		alt_name := from_start ? "last" : "first"
-		path := tmpl.path != "" ? tmpl.path : "<input>"
-		diag := format_tag_error(
-			path,
-			tmpl.source,
-			op_pos,
-			fmt.tprintf("%s %d is equivalent to %s %d", op_name, n, alt_name, 0 - n),
-			"consider using the clearer form",
-		)
-		log.warnf("%s", diag)
+		warning = Error_Body {
+			msg = fmt.tprintf("%s %d is equivalent to %s %d", op_name, n, alt_name, 0 - n),
+			pos = tag_pos,
+			kind = .Warning,
+			source = tmpl.source,
+			path = tmpl.path,
+			hint = "consider using the clearer form",
+		}
 		from_start = !from_start
 		n = 0 - n
 	}
@@ -522,9 +533,9 @@ take :: proc(
 		for j in start ..< end {
 			append(&result, extract_list_element(elem_info, data, j))
 		}
-		return result, nil
+		return any{new_clone(result, context.temp_allocator), typeid_of([dynamic]any)}, warning
 	} else {
-		return str[start:end], nil
+		return any{new_clone(str[start:end], context.temp_allocator), typeid_of(string)}, warning
 	}
 }