add examples

util/loader.py

@@ -0,0 +1,79 @@
+import os.path
+from framework.conformance import Conformance, render_conformance_check_result
+from concrete_syntax.textual_od import parser
+from transformation.rule import Rule
+
+# parse model and check conformance
+def parse_and_check(state, m_cs, mm, descr: str):
+    try:
+        m = parser.parse_od(
+            state,
+            m_text=m_cs,
+            mm=mm,
+        )
+    except Exception as e:
+        e.add_note("While parsing model " + descr)
+        raise
+    try:
+        conf = Conformance(state, m, mm)
+        errors = conf.check_nominal()
+        if len(errors) > 0:
+            print(render_conformance_check_result(errors))
+    except Exception as e:
+        e.add_note("In model " + descr)
+        raise
+    return m
+
+# get file contents as string
+def read_file(filename):
+    with open(filename) as file:
+        return file.read()
+
+KINDS = ["nac", "lhs", "rhs"]
+
+# load model transformation rules
+def load_rules(state, get_filename, rt_mm_ramified, rule_names):
+    rules = {}
+
+    files_read = []
+
+    for rule_name in rule_names:
+        rule = {}
+
+        def parse(kind):
+            filename = get_filename(rule_name, kind)
+            descr = "'"+filename+"'"
+            if kind == "nac":
+                suffix = ""
+                nacs = []
+                try:
+                    while True:
+                        base, ext = os.path.splitext(filename)
+                        processed_filename = base+suffix+ext
+                        nac = parse_and_check(state, read_file(processed_filename), rt_mm_ramified, descr)
+                        nacs.append(nac)
+                        suffix = "2" if suffix == "" else str(int(suffix)+1)
+                        files_read.append(processed_filename)
+                except FileNotFoundError:
+                    if suffix == "":
+                        print(f"Warning: rule {rule_name} has no NAC ({filename} not found)")
+                return nacs
+            elif kind == "lhs" or kind == "rhs":
+                try:
+                    m = parse_and_check(state, read_file(filename), rt_mm_ramified, descr)
+                    files_read.append(filename)
+                    return m
+                except FileNotFoundError as e:
+                    print(f"Warning: using empty {kind} ({filename} not found)")
+                    # Use empty model as fill-in:
+                    return parse_and_check(
+                        state,
+                        "",
+                        rt_mm_ramified,
+                        descr="'"+filename+"'")
+
+        rules[rule_name] = Rule(*(parse(kind) for kind in KINDS))
+
+    print("Rules loaded:\n" + '\n'.join(files_read))
+
+    return rules