Improve docs & Add JSON decode example (#121)

examples/usage/json_decode.py

@@ -0,0 +1,81 @@
+"""
+Usage:
+python -m sglang.launch_server --model-path meta-llama/Llama-2-7b-chat-hf --port 30000
+python json_decode.py
+"""
+from enum import Enum
+
+from pydantic import BaseModel, constr
+import sglang as sgl
+from sglang.srt.constrained.json_schema import build_regex_from_object
+
+
+character_regex = (
+    r"""\{\n"""
+    + r"""    "name": "[\w\d\s]{1,16}",\n"""
+    + r"""    "house": "(Gryffindor|Slytherin|Ravenclaw|Hufflepuff)",\n"""
+    + r"""    "blood status": "(Pure-blood|Half-blood|Muggle-born)",\n"""
+    + r"""    "occupation": "(student|teacher|auror|ministry of magic|death eater|order of the phoenix)",\n"""
+    + r"""    "wand": \{\n"""
+    + r"""        "wood": "[\w\d\s]{1,16}",\n"""
+    + r"""        "core": "[\w\d\s]{1,16}",\n"""
+    + r"""        "length": [0-9]{1,2}\.[0-9]{0,2}\n"""
+    + r"""    \},\n"""
+    + r"""    "alive": "(Alive|Deceased)",\n"""
+    + r"""    "patronus": "[\w\d\s]{1,16}",\n"""
+    + r"""    "bogart": "[\w\d\s]{1,16}"\n"""
+    + r"""\}"""
+)
+
+
+@sgl.function
+def character_gen(s, name):
+    s += name + " is a character in Harry Potter. Please fill in the following information about this character.\n"
+    s += sgl.gen("json_output", max_tokens=256, regex=character_regex)
+
+
+def driver_character_gen():
+    state = character_gen.run(name="Hermione Granger")
+    print(state.text())
+
+
+class Weapon(str, Enum):
+    sword = "sword"
+    axe = "axe"
+    mace = "mace"
+    spear = "spear"
+    bow = "bow"
+    crossbow = "crossbow"
+
+
+class Wizard(BaseModel):
+    name: str
+    age: int
+    weapon: Weapon
+
+
+@sgl.function
+def pydantic_wizard_gen(s):
+    s += "Give me a description about a wizard in the JSON format.\n"
+    s += sgl.gen(
+        "character",
+        max_tokens=128,
+        temperature=0,
+        regex=build_regex_from_object(Wizard),  # Requires pydantic >= 2.0
+    )
+
+
+def driver_character_gen():
+    state = character_gen.run(name="Hermione Granger")
+    print(state.text())
+
+
+def driver_pydantic_wizard_gen():
+    state = pydantic_wizard_gen.run()
+    print(state.text())
+
+
+if __name__ == "__main__":
+    sgl.set_default_backend(sgl.RuntimeEndpoint("http://localhost:30000"))
+    driver_character_gen()
+    # driver_pydantic_wizard_gen()