snippets_translate: Implement rudimentary switch() handling

Pick-to: 6.5
Task-number: PYSIDE-1106
Change-Id: If19ac5a962aed846e4a127c652a9bae277999807
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

2 files changed, 61 insertions, 0 deletions

diff --git a/tools/snippets_translate/converter.py b/tools/snippets_translate/converter.py
index 757d39abb..372c923a7 100644
--- a/tools/snippets_translate/converter.py
+++ b/tools/snippets_translate/converter.py
@@ -36,13 +36,21 @@ RETURN_TYPE_PATTERN = re.compile(r"^[a-zA-Z0-9]+(<.*?>)? [\w]+::[\w\*\&]+\(.*\)$
 FUNCTION_PATTERN = re.compile(r"^[a-zA-Z0-9]+(<.*?>)? [\w\*\&]+\(.*\)$")
 ITERATOR_PATTERN = re.compile(r"(std::)?[\w]+<[\w]+>::(const_)?iterator")
 SCOPE_PATTERN = re.compile(r"[\w]+::")
+SWITCH_PATTERN = re.compile(r"^\s*switch\s*\(([a-zA-Z0-9_\.]+)\)\s*{.*$")
+CASE_PATTERN = re.compile(r"^(\s*)case\s+([a-zA-Z0-9_:\.]+):.*$")
+DEFAULT_PATTERN = re.compile(r"^(\s*)default:.*$")
 
 
 QUALIFIERS = {"public:", "protected:", "private:", "public slots:",
               "protected slots:", "private slots:", "signals:"}
 
 
+switch_var = None
+switch_branch = 0
+
+
 def snippet_translate(x):
+    global switch_var, switch_branch
 
     ## Cases which are not C++
     ## TODO: Maybe expand this with lines that doesn't need to be translated
@@ -136,6 +144,25 @@ def snippet_translate(x):
     if "throw" in x:
         x = handle_keywords(x, "throw", "raise")
 
+    switch_match = SWITCH_PATTERN.match(x)
+    if switch_match:
+        switch_var = switch_match.group(1)
+        switch_branch = 0
+        return ""
+
+    switch_match = CASE_PATTERN.match(x)
+    if switch_match:
+        indent = switch_match.group(1)
+        value = switch_match.group(2)
+        cond = "if" if switch_branch == 0 else "elif"
+        switch_branch += 1
+        return f"{indent}{cond} {switch_var} == {value}:"
+
+    switch_match = DEFAULT_PATTERN.match(x)
+    if switch_match:
+        indent = switch_match.group(1)
+        return f"{indent}else:"
+
     # handle 'void Class::method(...)' and 'void method(...)'
     if VOID_METHOD_PATTERN.search(x):
         x = handle_void_functions(x)
diff --git a/tools/snippets_translate/tests/test_converter.py b/tools/snippets_translate/tests/test_converter.py
index 15c42cebc..3620313e4 100644
--- a/tools/snippets_translate/tests/test_converter.py
+++ b/tools/snippets_translate/tests/test_converter.py
@@ -4,6 +4,11 @@
 from converter import snippet_translate as st
 
 
+def multi_st(lines):
+    result = [st(l) for l in lines.split("\n")]
+    return "\n".join(result)
+
+
 def test_comments():
     assert st("// This is a comment") == "# This is a comment"
     assert st("// double slash // inside") == "# double slash // inside"
@@ -438,6 +443,35 @@ def test_lambdas():
     pass
 
 
+def test_switch_case():
+    source = """switch (v) {
+case 1:
+    f1();
+    break;
+case 2:
+    f2();
+    break;
+default:
+    f3();
+    break;
+}
+"""
+    expected = """
+if v == 1:
+    f1()
+    break
+elif v == 2:
+    f2()
+    break
+else:
+    f3()
+    break
+
+"""
+
+    assert multi_st(source) == expected
+
+
 def test_std_function():
     # std::function<QImage(const QImage &)> scale = [](const QImage &img) {
     pass