src/Tools/VSCode/extension/isabelle-ml-grammar.json

clarified output;

{
  "name": "Isabelle/ML",
  "scopeName": "source.isabelle-ml",
  "fileTypes": ["ML", "sml", "sig"],
  "uuid": "aa32eb5e-d0d9-11e6-b7a4-37ba001f1e6e",
  "keyEquivalent": "^~M",
  "repository": {
    "comments": {
      "patterns": [
        {
          "end": "\\*\\)",
          "begin": "\\(\\*",
          "beginCaptures": {
            "0": {
              "name": "punctuation.definition.comment.begin.ml"
            }
          },
          "patterns": [
            {
              "include": "#comments"
            }
          ],
          "endCaptures": {
            "0": {
              "name": "punctuation.definition.comment.end.ml"
            }
          },
          "name": "comment.block.ml"
        }
      ]
    },
    "spec": {
      "patterns": [
        {
          "match": "\\b(exception|type)\\s+([a-zA-Z][a-zA-Z0-9'_]*)",
          "captures": {
            "1": {
              "name": "keyword.other.ml"
            },
            "2": {
              "name": "entity.name.type.abbrev.ml"
            }
          },
          "name": "meta.spec.ml.type"
        },
        {
          "end": "(?=val|type|eqtype|datatype|structure|include|exception)",
          "begin": "\\b(datatype)\\s+([a-zA-Z][a-zA-Z0-9'_]*)\\s*(?==)",
          "patterns": [
            {
              "match": "\\b(and)\\s+([a-zA-Z][a-zA-Z0-9'_]*)\\s*(?==)",
              "captures": {
                "1": {
                  "name": "keyword.other.ml"
                },
                "2": {
                  "name": "entity.name.type.datatype.ml"
                }
              },
              "name": "meta.spec.ml.datatype"
            },
            {
              "match": "(?x)\n\t\t\t\t\t\t\t=\\s*([a-zA-Z][a-zA-Z0-9'_]*)(\\s+of)?",
              "captures": {
                "1": {
                  "name": "variable.other.dcon.ml"
                },
                "2": {
                  "name": "keyword.other.ml"
                }
              },
              "name": "meta.datatype.rule.main.ml"
            },
            {
              "match": "\\|\\s*([a-zA-Z][a-zA-Z0-9'_]*)(\\s+of)?",
              "captures": {
                "1": {
                  "name": "variable.other.dcon.ml"
                },
                "2": {
                  "name": "keyword.other.ml"
                }
              },
              "name": "meta.datatype.rule.other.ml"
            }
          ],
          "captures": {
            "1": {
              "name": "keyword.other.ml"
            },
            "2": {
              "name": "entity.name.type.datatype.ml"
            }
          },
          "name": "meta.spec.ml.datatype"
        },
        {
          "match": "\\b(val)\\s*([^:]+)\\s*:",
          "captures": {
            "1": {
              "name": "keyword.other.ml"
            }
          },
          "name": "meta.spec.ml.val"
        },
        {
          "end": "(?=val|type|eqtype|datatype|structure|include)",
          "begin": "\\b(structure)\\s*(\\w+)\\s*:",
          "patterns": [
            {
              "match": "\\b(sharing)\\b",
              "name": "keyword.other.ml"
            }
          ],
          "captures": {
            "1": {
              "name": "keyword.other.ml"
            },
            "2": {
              "name": "entity.name.type.module.ml"
            }
          },
          "name": "meta.spec.ml.structure"
        },
        {
          "match": "\\b(include)\\b",
          "captures": {
            "1": {
              "name": "keyword.other.ml"
            }
          },
          "name": "meta.spec.ml.include"
        },
        {
          "include": "#comments"
        }
      ]
    }
  },
  "patterns": [
    {
      "include": "#comments"
    },
    {
      "match": "\\b(val|datatype|signature|type|op|sharing|struct|as|let|in|abstype|local|where|case|of|fn|raise|exception|handle|ref|infix|infixr|before|end|structure|withtype)\\b",
      "name": "keyword.other.ml"
    },
    {
      "end": "\\b(end)\\b",
      "begin": "\\b(let)\\b",
      "patterns": [
        {
          "include": "$self"
        }
      ],
      "captures": {
        "1": {
          "name": "keyword.other.ml"
        },
        "2": {
          "name": "keyword.other.ml"
        }
      },
      "name": "meta.exp.let.ml"
    },
    {
      "end": "\\b(end)\\b",
      "begin": "\\b(sig)\\b",
      "patterns": [
        {
          "include": "#spec"
        }
      ],
      "captures": {
        "1": {
          "name": "keyword.other.delimiter.ml"
        },
        "2": {
          "name": "keyword.other.delimiter.ml"
        }
      },
      "name": "meta.module.sigdec.ml"
    },
    {
      "match": "\\b(if|then|else)\\b",
      "name": "keyword.control.ml"
    },
    {
      "end": "(?=val|type|eqtype|datatype|structure|local)",
      "begin": "\\b(fun|and)\\s+([\\w]+)\\b",
      "patterns": [
        {
          "include": "source.isabelle-ml"
        }
      ],
      "captures": {
        "1": {
          "name": "keyword.control.fun.ml"
        },
        "2": {
          "name": "entity.name.function.ml"
        }
      },
      "name": "meta.definition.fun.ml"
    },
    {
      "end": "\"",
      "begin": "\"",
      "beginCaptures": {
        "0": {
          "name": "punctuation.definition.string.begin.ml"
        }
      },
      "patterns": [
        {
          "match": "\\\\.",
          "name": "constant.character.escape.ml"
        }
      ],
      "endCaptures": {
        "0": {
          "name": "punctuation.definition.string.end.ml"
        }
      },
      "name": "string.quoted.double.ml"
    },
    {
      "match": "(#\")(\\\\)?.(\")",
      "captures": {
        "3": {
          "name": "punctuation.definition.constant.ml"
        },
        "1": {
          "name": "punctuation.definition.constant.ml"
        }
      },
      "name": "constant.character.ml"
    },
    {
      "match": "\\b\\d*\\.?\\d+\\b",
      "name": "constant.numeric.ml"
    },
    {
      "match": "\\b(andalso|orelse|not)\\b",
      "name": "keyword.operator.logical.ml"
    },
    {
      "end": "(?==|:|\\()",
      "begin": "(?x)\\b\n\t\t\t\t\t(functor|structure|signature)\\s+\n\t\t\t\t\t(\\w+)\\s* # identifier",
      "captures": {
        "1": {
          "name": "storage.type.module.binder.ml"
        },
        "2": {
          "name": "entity.name.type.module.ml"
        }
      },
      "name": "meta.module.dec.ml"
    },
    {
      "match": "\\b(open)\\b",
      "name": "keyword.other.module.ml"
    },
    {
      "match": "\\b(nil|true|false|NONE|SOME)\\b",
      "name": "constant.language.ml"
    },
    {
      "end": "$",
      "begin": "\\b(type|eqtype) .* =",
      "patterns": [
        {
          "match": "(([a-zA-Z0-9\\.\\* ]|(\\->))*)",
          "name": "meta.typeexp.ml"
        }
      ],
      "captures": {
        "1": {
          "name": "keyword.other.typeabbrev.ml"
        },
        "2": {
          "name": "variable.other.typename.ml"
        }
      },
      "name": "meta.typeabbrev.ml"
    }
  ]
}