Merge pull request #579

Fix/multiline string expressions

Author: drazvan

examples/v2_x/language_reference/use_llms/interaction_loop/main.co

@@ -10,7 +10,7 @@ flow main
         when unhandled user intent
             llm continue interaction
         or when user was silent 12.0
-            $response = i"A random fun fact"
+            $response = ..."A random fun fact"
             bot say $response
         or when user expressed greeting
             bot say "Hi there!"

examples/v2_x/tutorial/guardrails_1/rails.co

@@ -24,6 +24,6 @@ flow input rails $input_text
     abort
 
 flow check user utterance $input_text -> $input_safe
-  $is_safe = i"Consider the following user utterance: '{$input_text}'. Assign 'True' if appropriate, 'False' if inappropriate."
+  $is_safe = ..."Consider the following user utterance: '{$input_text}'. Assign 'True' if appropriate, 'False' if inappropriate."
   print $is_safe
   return $is_safe

nemoguardrails/colang/v2_x/lang/expansion.py

@@ -41,7 +41,10 @@
 )
 from nemoguardrails.colang.v2_x.runtime.errors import ColangSyntaxError
 from nemoguardrails.colang.v2_x.runtime.flows import FlowConfig, InternalEvents
-from nemoguardrails.colang.v2_x.runtime.utils import new_var_uid
+from nemoguardrails.colang.v2_x.runtime.utils import (
+    escape_special_string_characters,
+    new_var_uid,
+)
 
 
 def expand_elements(
@@ -676,11 +679,12 @@ def _expand_assignment_stmt_element(element: Assignment) -> List[ElementType]:
     new_elements: List[ElementType] = []
 
     # Check if the expression is an NLD instruction
-    nld_instruction_pattern = r"^\s*i\"(.*)\"|^\s*i'(.*)'"
+    nld_instruction_pattern = r'\.\.\.\s*("""|\'\'\')((?:\\\1|(?!\1)[\s\S])*?)\1|\.\.\.\s*("|\')((?:\\\3|(?!\3).)*?)\3'
     match = re.search(nld_instruction_pattern, element.expression)
 
     if match:
         # Replace the assignment with the GenerateValueAction system action
+        instruction = escape_special_string_characters(match.group(2) or match.group(4))
         new_elements.append(
             SpecOp(
                 op="await",
@@ -689,7 +693,7 @@ def _expand_assignment_stmt_element(element: Assignment) -> List[ElementType]:
                     spec_type=SpecType.ACTION,
                     arguments={
                         "var_name": f'"{element.key}"',
-                        "instructions": f'"{match.group(1) or match.group(2)}"',
+                        "instructions": f'"{instruction}"',
                     },
                 ),
                 return_var_name=element.key,

nemoguardrails/colang/v2_x/lang/grammar/colang.lark

@@ -222,8 +222,8 @@ _NEWLINE: (/\r?\n[\t ]*/)+
 
 // Primitive values
 
-STRING: /i?("(?!"").*?(?<!\\)(\\\\)*?"|i?'(?!'').*?(?<!\\)(\\\\)*?')/i
-LONG_STRING: /(""".*?(?<!\\)(\\\\)*?"""|'''.*?(?<!\\)(\\\\)*?''')/is
+STRING: /(\.\.\.\s*)?("(?!"").*?(?<!\\)(\\\\)*?"|(\.\.\.\s*)?'(?!'').*?(?<!\\)(\\\\)*?')/i
+LONG_STRING: /(\.\.\.\s*)?(""".*?(?<!\\)(\\\\)*?"""|(\.\.\.\s*)?'''.*?(?<!\\)(\\\\)*?''')/is
 
 _SPECIAL_DEC: "0".."9"        ("_"?  "0".."9"                       )*
 DEC_NUMBER:   "1".."9"        ("_"?  "0".."9"                       )*

nemoguardrails/colang/v2_x/lang/parser.py

@@ -59,9 +59,6 @@ def _apply_pre_parsing_expansions(content: str):
 
         Currently, only the "..." is expanded.
         """
-        # Replace ..."NLD" with i"NLD"
-        content = re.sub(r"\.\.\.(['\"])(.*?)\1", r'i"\2"', content)
-
         # We make sure to capture the correct indentation level and use that.
         content = re.sub(
             r"\n( +)\.\.\.",

nemoguardrails/colang/v2_x/runtime/eval.py

@@ -26,7 +26,10 @@
 from nemoguardrails.colang.v2_x.runtime import system_functions
 from nemoguardrails.colang.v2_x.runtime.errors import ColangValueError
 from nemoguardrails.colang.v2_x.runtime.flows import FlowState, State
-from nemoguardrails.colang.v2_x.runtime.utils import AttributeDict
+from nemoguardrails.colang.v2_x.runtime.utils import (
+    AttributeDict,
+    escape_special_string_characters,
+)
 from nemoguardrails.eval.cli.simplify_formatter import SimplifyFormatter
 from nemoguardrails.utils import new_uuid
 
@@ -67,14 +70,17 @@ def eval_expression(expr: str, context: dict) -> Any:
 
     # We search for all expressions in strings within curly brackets and evaluate them first
     # Find first all strings
-    string_pattern = r'("(?:\\"|[^"])*?")|(\'(?:\\\'|[^\'])*?\')'
+    string_pattern = (
+        r'("""|\'\'\')((?:\\\1|(?!\1)[\s\S])*?)\1|("|\')((?:\\\3|(?!\3).)*?)\3'
+    )
     string_expressions_matches = re.findall(string_pattern, expr)
     string_expression_values = []
     for string_expression_match in string_expressions_matches:
+        character = string_expression_match[0] or string_expression_match[2]
         string_expression = (
-            string_expression_match[0]
-            if string_expression_match[0]
-            else string_expression_match[1]
+            character
+            + (string_expression_match[1] or string_expression_match[3])
+            + character
         )
         if string_expression:
             # Find expressions within curly brackets, ignoring double curly brackets
@@ -89,7 +95,12 @@ def eval_expression(expr: str, context: dict) -> Any:
                         raise ColangValueError(
                             f"Error evaluating inner expression: '{inner_expression}'"
                         ) from ex
-                    value = str(value).replace('"', '\\"').replace("'", "\\'")
+
+                    value = str(value)
+
+                    # Escape special characters
+                    value = escape_special_string_characters(value)
+
                     inner_expression_values.append(value)
                 string_expression = re.sub(
                     expression_pattern,

nemoguardrails/colang/v2_x/runtime/utils.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import re
 import uuid
 
 
@@ -40,3 +41,23 @@ def new_readable_uid(name: str) -> str:
 def new_var_uid() -> str:
     """Creates a new uuid that is compatible with variable names."""
     return str(uuid.uuid4()).replace("-", "_")
+
+
+def escape_special_string_characters(string: str) -> str:
+    """Escapes all occurrences of special characters."""
+    # Replace " or ' with \\" or \\' if not already escaped
+    string = re.sub(r"(^|[^\\])('|\")", r"\1\\\2", string)
+    # Replace other special characters
+    escaped_characters_map = {
+        "\n": "\\n",
+        "\t": "\\t",
+        "\r": "\\r",
+        "\b": "\\b",
+        "\f": "\\f",
+        "\v": "\\v",
+    }
+
+    for c, s in escaped_characters_map.items():
+        string = str(string).replace(c, s)
+
+    return string

tests/v2_x/test_llm_value_generation.py

@@ -0,0 +1,65 @@
+# SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+
+from rich.logging import RichHandler
+
+from nemoguardrails import RailsConfig
+from tests.utils import TestChat
+
+FORMAT = "%(message)s"
+logging.basicConfig(
+    level=logging.DEBUG,
+    format=FORMAT,
+    datefmt="[%X,%f]",
+    handlers=[RichHandler(markup=True)],
+)
+
+
+def test_1():
+    """Test use of expression as statements."""
+    config = RailsConfig.from_content(
+        colang_content="""
+        flow main
+          match UtteranceUserActionFinished()
+          $v1 = ..."Generate the company' name\\" from users input"
+          $v2 = ... 'Generate the company\\' name" from users input'
+          $v3 = ...'''Generate the company' name" from users input'''
+          $v4 = ...  '''Generate the company'
+                    name" from users input'''
+
+          await UtteranceBotAction(script="{$v1}{$v2}{$v3}{$v4}")
+        """,
+        yaml_content="""
+        colang_version: "2.x"
+        models:
+        - type: main
+          engine: openai
+          model: gpt-3.5-turbo-instruct
+        """,
+    )
+
+    chat = TestChat(
+        config,
+        llm_completions=["'1'", "'2'", "'3'", "'4'"],
+    )
+
+    chat >> "hi"
+    chat << "1234"
+
+
+if __name__ == "__main__":
+    test_1()

tests/v2_x/test_slide_mechanics.py

@@ -229,9 +229,12 @@ def test_expressions_in_strings():
 
     content = """
     flow main
-      start UtteranceBotAction(script="Roger") as $ref
+      $xyz = 'x\\'y\\'z\\n'
+      $test = '''Roger's
+                test:\n {$xyz}'''
+      start UtteranceBotAction(script=$test) as $ref
       start UtteranceBotAction(script="It's {{->}}")
-      start UtteranceBotAction(script='It"s {{->}} \\'{$ref.start_event_arguments.script}!\\'')
+      await UtteranceBotAction(script='It"s {{->}} \\'{$ref.start_event_arguments.script}!\\'')
     """
 
     config = _init_state(content)
@@ -241,20 +244,44 @@ def test_expressions_in_strings():
         [
             {
                 "type": "StartUtteranceBotAction",
-                "script": "Roger",
+                "script": "Roger's\n                test:\n x'y'z\n",
             },
             {
                 "type": "StartUtteranceBotAction",
                 "script": "It's {->}",
             },
             {
                 "type": "StartUtteranceBotAction",
-                "script": "It\"s {->} 'Roger!'",
+                "script": "It\"s {->} 'Roger's\n                test:\n x'y'z\n!'",
             },
         ],
     )
 
 
+def test_multiline_string():
+    """Test string expression evaluation."""
+
+    content = '''
+    flow main
+      $var = "Test"
+      $string = """This is a multiline
+      string! '{$var}' "hi" """
+      start UtteranceBotAction(script=$string)
+    '''
+
+    config = _init_state(content)
+    state = run_to_completion(config, start_main_flow_event)
+    assert is_data_in_events(
+        state.outgoing_events,
+        [
+            {
+                "type": "StartUtteranceBotAction",
+                "script": "This is a multiline\n      string! 'Test' \"hi\" ",
+            }
+        ],
+    )
+
+
 def test_flow_return_values():
     """Test flow return value handling."""
 
@@ -950,4 +977,4 @@ def test_expression_evaluation():
 
 
 if __name__ == "__main__":
-    test_expression_evaluation()
+    test_multiline_string()