diff --git a/gozcl/doc.go b/gozcl/doc.go new file mode 100644 index 0000000..33fe948 --- /dev/null +++ b/gozcl/doc.go @@ -0,0 +1,49 @@ +// Package gozcl allows decoding zcl configurations into Go data structures. +// +// It provides a convenient and concise way of describing the schema for +// configuration and then accessing the resulting data via native Go +// types. +// +// A struct field tag scheme is used, similar to other decoding and +// unmarshalling libraries. The tags are formatted as in the following example: +// +// ThingType string `zcl:"thing_type,attr"` +// +// Within each tag there are two comma-separated tokens. The first is the +// name of the corresponding construct in configuration, while the second +// is a keyword giving the kind of construct expected. The following +// kind keywords are supported: +// +// attr (the default) indicates that the value is to be populated from an attribute +// block indicates that the value is to populated from a block +// label indicates that the value is to populated from a block label +// remain indicates that the value is to be populated from the remaining body after populating other fields +// +// "attr" fields may either be of type *zcl.Expression, in which case the raw +// expression is assigned, or of any type accepted by gocty, in which case +// gocty will be used to assign the value to a native Go type. +// +// "block" fields may be of type *zcl.Block or zcl.Body, in which case the +// corresponding raw value is assigned, or may be a struct that recursively +// uses the same tags. Block fields may also be slices of any of these types, +// in which case multiple blocks of the corresponding type are decoded into +// the slice. +// +// "label" fields are considered only in a struct used as the type of a field +// marked as "block", and are used sequentially to capture the labels of +// the blocks being decoded. In this case, the name token is used only as +// an identifier for the label in diagnostic messages. +// +// "remain" can be placed on a single field that may be either of type +// zcl.Body or zcl.Attributes, in which case any remaining body content is +// placed into this field for delayed processing. If no "remain" field is +// present then any attributes or blocks not matched by another valid tag +// will cause an error diagnostic. +// +// Broadly-speaking this package deals with two types of error. The first is +// errors in the configuration itself, which are returned as diagnostics +// written with the configuration author as the target audience. The second +// is bugs in the calling program, such as invalid struct tags, which are +// surfaced via panics since there can be no useful runtime handling of such +// errors and they should certainly not be returned to the user as diagnostics. +package gozcl