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bdc2878 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 | """Tool call parser — extract structured tool calls from model text output.
Tries multiple formats in priority order:
1. <tool_calls> XML (canonical format we inject)
2. JSON envelope {"tool_calls": [...]}
3. JSON array [{"name": ..., "input": ...}]
4. Alternative XML tags (<function_call>, <invoke>)
Returns a list of ParsedToolCall dataclasses.
"""
from __future__ import annotations
import json
import os
import re
import time
from dataclasses import dataclass, field
from typing import Any
# ---------------------------------------------------------------------------
# Data model
# ---------------------------------------------------------------------------
@dataclass
class ParsedToolCall:
call_id: str
name: str
arguments: str # always a JSON string
@staticmethod
def make(name: str, arguments: Any) -> "ParsedToolCall":
call_id = f"call_{int(time.time() * 1000)}{os.urandom(3).hex()}"
if isinstance(arguments, str):
args_str = arguments
else:
try:
args_str = json.dumps(arguments, ensure_ascii=False, separators=(",", ":"))
except (TypeError, ValueError):
args_str = "{}"
return ParsedToolCall(call_id=call_id, name=name, arguments=args_str)
@dataclass
class ParseResult:
calls: list[ParsedToolCall] = field(default_factory=list)
saw_tool_syntax: bool = False # detected XML/JSON envelope even if parsing failed
# ---------------------------------------------------------------------------
# Public entry point
# ---------------------------------------------------------------------------
def parse_tool_calls(
text: str,
available_tools: list[str] | None = None,
) -> ParseResult:
"""Parse tool calls from model-generated text.
Args:
text: Full or partial model output text.
available_tools: If provided, only calls whose name appears in this
list are accepted (case-sensitive).
"""
result = ParseResult()
if not text or not text.strip():
return result
# Fast path: check whether tool-call syntax is present at all
if not _has_tool_syntax(text):
return result
result.saw_tool_syntax = True
# Try parsers in priority order
calls = (
_parse_xml_tool_calls(text)
or _parse_json_envelope(text)
or _parse_json_array(text)
or _parse_alt_xml(text)
)
if calls and available_tools:
calls = [c for c in calls if c.name in available_tools]
result.calls = calls or []
return result
# ---------------------------------------------------------------------------
# Syntax detection
# ---------------------------------------------------------------------------
_TOOL_SYNTAX_PATTERNS = re.compile(
r"<tool_calls|<tool_call|<function_call|<invoke\s|"
r'"tool_calls"\s*:|\btool_calls\b',
re.IGNORECASE,
)
def _has_tool_syntax(text: str) -> bool:
return bool(_TOOL_SYNTAX_PATTERNS.search(text))
# ---------------------------------------------------------------------------
# Parser 1: <tool_calls> XML (canonical)
# ---------------------------------------------------------------------------
_XML_ROOT_RE = re.compile(r"<tool_calls\s*>(.*?)</tool_calls\s*>", re.DOTALL | re.IGNORECASE)
_XML_CALL_RE = re.compile(r"<tool_call\s*>(.*?)</tool_call\s*>", re.DOTALL | re.IGNORECASE)
_XML_NAME_RE = re.compile(r"<tool_name\s*>(.*?)</tool_name\s*>", re.DOTALL | re.IGNORECASE)
_XML_PARAMS_RE = re.compile(r"<parameters\s*>(.*?)</parameters\s*>", re.DOTALL | re.IGNORECASE)
def _parse_xml_tool_calls(text: str) -> list[ParsedToolCall]:
root_m = _XML_ROOT_RE.search(text)
if not root_m:
return []
calls: list[ParsedToolCall] = []
for call_m in _XML_CALL_RE.finditer(root_m.group(1)):
inner = call_m.group(1)
name_m = _XML_NAME_RE.search(inner)
params_m = _XML_PARAMS_RE.search(inner)
if not name_m:
continue
name = name_m.group(1).strip()
params = params_m.group(1).strip() if params_m else "{}"
parsed_args = _parse_json_tolerant(params)
if parsed_args is None:
continue
calls.append(ParsedToolCall.make(name, parsed_args))
return calls
# ---------------------------------------------------------------------------
# Parser 2: {"tool_calls": [...]} JSON envelope
# ---------------------------------------------------------------------------
def _parse_json_envelope(text: str) -> list[ParsedToolCall]:
# Only attempt if the text literally contains "tool_calls" key
if '"tool_calls"' not in text:
return []
obj = _extract_outermost_json_obj(text)
if not isinstance(obj, dict):
return []
raw_calls = obj.get("tool_calls")
if not isinstance(raw_calls, list):
return []
return _extract_from_call_list(raw_calls)
_JSON_DECODER = json.JSONDecoder()
def _extract_outermost_json_obj(text: str) -> Any:
"""Find and parse the first top-level JSON object in *text*.
Uses JSONDecoder.raw_decode which handles the object boundary correctly
without a manual bracket-depth tracker.
"""
start = text.find("{")
if start == -1:
return None
try:
obj, _ = _JSON_DECODER.raw_decode(text, start)
return obj
except (json.JSONDecodeError, ValueError):
# Attempt repair on the substring from first '{' onward
end = text.rfind("}") + 1
return _try_repair_json(text[start:end]) if end > start else None
# ---------------------------------------------------------------------------
# Parser 3: bare JSON array [{"name":..., "input":...}]
# ---------------------------------------------------------------------------
_JSON_ARR_RE = re.compile(r"\[[\s\S]+\]", re.DOTALL)
def _parse_json_array(text: str) -> list[ParsedToolCall]:
m = _JSON_ARR_RE.search(text)
if not m:
return []
try:
arr = json.loads(m.group(0))
except (json.JSONDecodeError, ValueError):
return []
if not isinstance(arr, list):
return []
return _extract_from_call_list(arr)
def _extract_from_call_list(items: list[Any]) -> list[ParsedToolCall]:
calls: list[ParsedToolCall] = []
for item in items:
if not isinstance(item, dict):
continue
name = (item.get("name") or item.get("tool_name") or "").strip()
args = item.get("input") or item.get("arguments") or item.get("parameters") or {}
if not name:
continue
calls.append(ParsedToolCall.make(name, args))
return calls
# ---------------------------------------------------------------------------
# Parser 4: alternative XML tags (<function_call>, <invoke name="...">)
# ---------------------------------------------------------------------------
_FC_RE = re.compile(r"<function_call\s*>(.*?)</function_call\s*>", re.DOTALL | re.IGNORECASE)
_INVOKE_RE = re.compile(r'<invoke\s+name=["\']?(\w+)["\']?\s*>(.*?)</invoke\s*>', re.DOTALL | re.IGNORECASE)
_FC_NAME_RE = re.compile(r"<name\s*>(.*?)</name\s*>", re.DOTALL | re.IGNORECASE)
_FC_ARGS_RE = re.compile(r"<arguments\s*>(.*?)</arguments\s*>", re.DOTALL | re.IGNORECASE)
def _parse_alt_xml(text: str) -> list[ParsedToolCall]:
calls: list[ParsedToolCall] = []
# <function_call><name>...</name><arguments>...</arguments></function_call>
for m in _FC_RE.finditer(text):
inner = m.group(1)
name_m = _FC_NAME_RE.search(inner)
args_m = _FC_ARGS_RE.search(inner)
if not name_m:
continue
name = name_m.group(1).strip()
args = _parse_json_tolerant(args_m.group(1).strip() if args_m else "{}")
if args is None:
continue
calls.append(ParsedToolCall.make(name, args))
# <invoke name="tool_name">...</invoke>
for m in _INVOKE_RE.finditer(text):
name = m.group(1).strip()
inner = m.group(2)
args = _parse_json_tolerant(inner.strip())
if args is None:
args = {}
calls.append(ParsedToolCall.make(name, args))
return calls
# ---------------------------------------------------------------------------
# JSON helpers
# ---------------------------------------------------------------------------
def _parse_json_tolerant(s: str) -> Any:
"""Try to parse JSON; attempt light repair on failure."""
if not s:
return {}
try:
return json.loads(s)
except (json.JSONDecodeError, ValueError):
repaired = _try_repair_json(s)
return repaired
def _try_repair_json(s: str) -> Any:
"""Very lightweight JSON repair: fix unescaped newlines inside strings."""
try:
# Replace literal newlines inside strings (common model output issue)
fixed = re.sub(r'(?<!\\)\n', r'\\n', s)
return json.loads(fixed)
except (json.JSONDecodeError, ValueError):
return None
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