providers/strings: Add string functions provider

providers/strings/strings.go

@@ -0,0 +1,73 @@
+package strings
+
+import "strings"
+import "unicode"
+import "html/template"
+import "git.tebibyte.media/sashakoshka/step"
+
+var _ step.FuncProvider = new(Provider)
+
+// Provider provides string functions.
+type Provider struct {
+	
+}
+
+// Package fulfills the step.Provider interface.
+func (this *Provider) Package () string {
+	return "strings"
+}
+
+// FuncMap fulfills the step.FuncProvider interface.
+func (this *Provider) FuncMap () template.FuncMap {
+	return template.FuncMap {
+		"strip":              funcStrip,
+		"stripAny":           funcStripAny,
+		"stripNonLetters":    funcStripNonLetters,
+		"stripNonPrintables": funcStripNonPrintables,
+		"stripSlashes":       funcStripSlashes,
+	}
+}
+
+func funcStrip (input string) string {
+	output := strings.Builder { }
+	for _, run := range input {
+		if !unicode.IsSpace(run) {
+			output.WriteRune(run)
+		}
+	}
+	return output.String()
+}
+
+func funcStripAny (chars, input string) string {
+	output := strings.Builder { }
+	for _, run := range input {
+		if strings.IndexRune(chars, run) < 0 {
+			output.WriteRune(run)
+		}
+	}
+	return output.String()
+}
+
+func funcStripNonLetters (input string) string {
+	output := strings.Builder { }
+	for _, run := range input {
+		if unicode.IsLetter(run) {
+			output.WriteRune(run)
+		}
+	}
+	return output.String()
+}
+
+func funcStripNonPrintables (input string) string {
+	output := strings.Builder { }
+	for _, run := range input {
+		if unicode.IsPrint(run) {
+			output.WriteRune(run)
+		}
+	}
+	return output.String()
+}
+
+func funcStripSlashes (input string) string {
+	return strings.ReplaceAll(input, "/", "")
+}