Re-wrote from scratch in Golang

- Re-implemented the project in Golang, and deprecated Python entirely
- Implemented several new, long-requested features
- Refactored cheatsheets into a separate repository

internal/config/validate.go

@@ -0,0 +1,64 @@
+package config
+
+import (
+	"fmt"
+)
+
+// Validate returns an error if the config is invalid
+func (c *Config) Validate() error {
+
+	// assert that an editor was specified
+	if c.Editor == "" {
+		return fmt.Errorf("config error: editor unspecified")
+	}
+
+	// assert that at least one cheatpath was specified
+	if len(c.Cheatpaths) == 0 {
+		return fmt.Errorf("config error: no cheatpaths specified")
+	}
+
+	// assert that each path and name is unique
+	names := make(map[string]bool)
+	paths := make(map[string]bool)
+
+	// assert that each cheatpath is valid
+	for _, cheatpath := range c.Cheatpaths {
+
+		// assert that the cheatpath is valid
+		if err := cheatpath.Validate(); err != nil {
+			return fmt.Errorf("config error: %v", err)
+		}
+
+		// assert that the name is unique
+		if _, ok := names[cheatpath.Name]; ok {
+			return fmt.Errorf(
+				"config error: cheatpath name is not unique: %s",
+				cheatpath.Name,
+			)
+		}
+		names[cheatpath.Name] = true
+
+		// assert that the path is unique
+		if _, ok := paths[cheatpath.Path]; ok {
+			return fmt.Errorf(
+				"config error: cheatpath path is not unique: %s",
+				cheatpath.Path,
+			)
+		}
+		paths[cheatpath.Path] = true
+	}
+
+	// TODO: assert valid styles?
+
+	// assert that the formatter is valid
+	formatters := map[string]bool{
+		"terminal":    true,
+		"terminal256": true,
+		"terminal16m": true,
+	}
+	if _, ok := formatters[c.Formatter]; !ok {
+		return fmt.Errorf("config error: formatter is invalid: %s", c.Formatter)
+	}
+
+	return nil
+}