51 lines
1.7 KiB
Go
51 lines
1.7 KiB
Go
package grammar
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import (
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"fmt"
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"strings"
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)
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// reservedInName is what a category, folder or field name may not contain: a dot
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// separates the segments of a path, '|' the arms of a token, '(' opens a function
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// call, braces delimit the token, '/' starts a reference, and brackets and a quote
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// open a JSON value. A name carrying one is rejected where it is authored rather
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// than where it would be unreachable.
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const reservedInName = ".|({}/[]\""
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var reservedList = strings.Join(strings.Split(reservedInName, ""), " ")
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// CheckName rejects a name the dot path, {token} and JSON grammars cannot spell, or a struct
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// tag cannot read.
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// Both a category or folder and a field go through it, so there is one answer to
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// what a name may contain.
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func CheckName(name string) error {
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if name == "" {
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return fmt.Errorf("%q is empty, which is not a path segment, so List never offers it", name)
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}
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if name == "-" {
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return fmt.Errorf(`%q is reserved: the struct tag fake:"-" leaves a field unfilled, so no tag could read it; rename it`, name)
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}
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if strings.Contains(name, AsWord) {
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return fmt.Errorf("%q contains %q, which a token reads as binding a name; rename it", name, AsWord)
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}
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if i := strings.IndexAny(name, reservedInName); i >= 0 {
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return fmt.Errorf("%q contains %q; a name may not use %s, which the dot path, {token} and JSON grammars reserve",
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name, name[i:i+1], reservedList)
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}
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return nil
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}
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// CheckPathNames rejects a dotted path with a segment no name may be.
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func CheckPathNames(path string) error {
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segs, err := SplitPath(path)
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if err != nil {
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return err
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}
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for _, seg := range NameSegments(segs) {
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if err := CheckName(seg); err != nil {
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return fmt.Errorf("path %w", err)
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}
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}
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return nil
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}
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