feat: help for misspelled pipes is now shown to the user.

mustache/diagnostic.odin

@@ -326,5 +326,5 @@ format_render_error :: proc(err: Error, tmpl: Template, colorize: bool = false)
 	if path == "" {
 		path = "<input>"
 	}
-	return format_error(path, source, b.pos, b.msg, colorize = colorize, span = b.span)
+	return format_error(path, source, b.pos, b.msg, hint = b.hint, colorize = colorize, span = b.span)
 }

mustache/mustache.odin

@@ -32,6 +32,7 @@ Error_Body :: struct {
 	source: string,
 	path:   string,
 	span:   int,
+	hint:   string,
 }
 
 // Error is nil when no error occurred.
@@ -59,6 +60,7 @@ tag_error :: proc(err: Error, tmpl: Template) -> Error {
 		msg    = b.msg,
 		pos    = b.pos,
 		span   = b.span,
+		hint   = b.hint,
 		kind   = b.kind,
 		source = tmpl.source,
 		path   = tmpl.path,

mustache/pipes.odin

@@ -259,11 +259,17 @@ resolve_format_string :: proc(name: string, ctx: []any, pos: int) -> (string, Er
 apply_filter :: proc(value: any, filter: ^Pipe_Filter, pos: int, ctx: []any) -> (any, Error) {
 	op, ok := pipe_op_from_string(filter.op)
 	if !ok {
+		hint := ""
+		suggestion := suggest_correction(pipe_op_candidates(), filter.op)
+		if suggestion != "" {
+			hint = fmt.tprintf("did you mean '%s'?", suggestion)
+		}
 		return nil, Error_Body {
 			msg  = fmt.tprintf("unknown pipe op '%s'", filter.op),
 			pos  = filter.op_pos,
 			span = len(filter.op),
 			kind = .Data,
+			hint = hint,
 		}
 	}
 

mustache/pipes_test.odin

@@ -2,6 +2,7 @@
 package mustache
 
 import "core:fmt"
+import "core:strings"
 import "core:testing"
 import "core:time/datetime"
 import "core:time/timezone"
@@ -561,3 +562,24 @@ test_format_mst_no_offset_no_timezone :: proc(t: ^testing.T) {
 	result, _ := render(tpl, data, {}, context.temp_allocator)
 	testing.expect_value(t, result, "UTC")
 }
+
+// --- pipe op suggestion tests ---
+
+@(test)
+test_unknown_pipe_op_suggestion :: proc(t: ^testing.T) {
+	filter := Pipe_Filter{op = "formats", op_pos = 0}
+	_, err := apply_filter("2026-01-15", &filter, 0, nil)
+	testing.expect(t, err != nil, "should error on unknown op")
+	b := body(err)
+	testing.expect(t, strings.contains(b.hint, "format"), "hint should suggest 'format'")
+	testing.expect(t, strings.contains(b.hint, "did you mean"), "hint should be a suggestion")
+}
+
+@(test)
+test_unknown_pipe_op_no_suggestion :: proc(t: ^testing.T) {
+	filter := Pipe_Filter{op = "xyz", op_pos = 0}
+	_, err := apply_filter("2026-01-15", &filter, 0, nil)
+	testing.expect(t, err != nil, "should error on unknown op")
+	b := body(err)
+	testing.expect(t, b.hint == "", "no suggestion expected for 'xyz'")
+}