Implemented switch statements

src/build/ast/parseSwitch.go

@@ -0,0 +1,37 @@
+package ast
+
+import (
+	"git.akyoto.dev/cli/q/src/build/expression"
+	"git.akyoto.dev/cli/q/src/build/token"
+)
+
+// parseSwitch generates the cases inside a switch statement.
+func parseSwitch(tokens token.List, source []byte) ([]Case, error) {
+	var cases []Case
+
+	err := EachInstruction(tokens, func(caseTokens token.List) error {
+		blockStart, _, body, err := block(caseTokens, source)
+
+		if err != nil {
+			return err
+		}
+
+		conditionTokens := caseTokens[:blockStart]
+		var condition *expression.Expression
+
+		if len(conditionTokens) == 1 && conditionTokens[0].Kind == token.Identifier && conditionTokens[0].Text(source) == "_" {
+			condition = nil
+		} else {
+			condition = expression.Parse(conditionTokens)
+		}
+
+		cases = append(cases, Case{
+			Condition: condition,
+			Body:      body,
+		})
+
+		return nil
+	})
+
+	return cases, err
+}