Release Notes

All releases can be accessed through the TinkerPop Maven2 repository identified below.

<repository>
  <id>tinkerpop-repository</id>
  <name>TinkerPop Maven2 Repository</name>
  <url>http://tinkerpop.com/maven2</url>
</repository>

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Version 0.9 (Gremlin the Grouch – April 4, 2011)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.9</version>
</dependency>

• Iterable and Iterator meta methods are now Pipe exclusive
• Index results are auto-wrapped in an IdentityPipe to ensure consistent behavior across graphs
• Added DexGraph as imported graph database
• Object.propertyMissing is no longer defined to ensure Gremlin safety
• emit step renamed to transform
• foreach step renamed to sideeffect
• Removed futuref step as back supplies necessary computation
• The it of the gather step is now the gathered List

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Version 0.8 (Grem Stefani — March 2, 2011)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.8</version>
</dependency>

• Added new steps
  • emit to emit results of provided closure
  • ifelse to perform a if/then/else branch
  • uniquePath to filter looping paths
• Added new methods
  • Object.mean() to calculate the average of delegate
  • Pipe.count() to calculate the number of objects in pipe
• Added support for stack trace printing during an error in the console
• loop step now requires “back integer”
• Added step caching model to increase speed of property notation
• Added outE(label), inE(label) and bothE(label) support
• Added support for dynamic counter adjustment in groupCount
• Bumped to using Groovy 1.7.8
• Created a type-cast friendly groupCount step

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Version 0.7 (Gremopoly — January 22, 2011)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.7</version>
</dependency>

• Added many new steps
  • loop step for in-line looping
  • foreach step for closure based operations on flowing objects
  • back step for backtracking in pipeline (i.e. ../)
  • aggregate, except, and retain for except/retain pattern
  • groupCount for map aggregations (i.e. g:op-value())
  • step for anonymous/lambda steps
• Massive refactoring of documentation
• Changed to Groovy as the host language

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Version 0.6 (Gremalicious — December 14, 2010)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.6</version>
</dependency>

• Fixed foreach bug that occurred on single object looping
• Fixed if/else bug that occurred on function call
• null and empty iterator/iterable result now printed in console
• Empty path expression returns an empty iterable, not null
• Added g:copy-ve() function that conveniently copies an element from one graph into another
• Fixed numerous bugs in how functions were computing atoms
• GPath optimization through auto-reset of Gremlin-specific range-based pipes
• Comparing numbers is now possible without casting
• Fixed a major bug in error message handling (many exceptions w/o message being provided in console)
• Improved Gremlin evaluator load time with static function and step loading
• Added support for Blueprints 0.3 multi-indexes
  • g:add-aidx-key(), g:add-idx(), g:drop-idx(), g:show-aidx-keys(), g:show-idx(), g:remove-aidx-keys()
• Added return ?object to return from a user defined function or step
• Added support for path generation through g:path() (main body of work in Pipes)

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Version 0.5.5 (Gremlivich — October 28, 2010)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.5.5</version>
</dependency>

• A rework of the user-defined step model
  • Renamed the concept of “path” to “step”
  • Users can now define computations in steps
• Added gather and scatter steps to allow for aggregation and unrolling of objects within a path
• Added g:append() function to concatenate objects to an iterable (e.g. list, set)

Version 0.5 (Gremlivich — September 22, 2010)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.5</version>
</dependency>

• A complete redesign and implementation of the Gremlin compiler
  • Compiler written using ANTLR 3.2
  • Virtual machine written using Pipes 0.1 and JSR 223.
• Significant performance improvements
  • Order of magnitude increase in speed for numerous operations
  • Lazy evaluation for better memory usage
• Functions implement the ServiceLoader pattern for ease of incorporating 3rd-party extensions
• Numerous changes to the Gremlin function library
  • All core functions are now in the g namespace (e.g. g:count(), g:string())
  • g:id() changed to g:id-v() and g:id-e() for getting vertices and edges, respectively
  • g:key() changed to g:key-v()
  • Added g:version() function to retrieve version information
  • Added g:g() (group) to semi-replace () model in Gremlin 0.2.2
  • Added g:flatten() to flatten embedded iterables
  • Added g:includes() to determine if an object is in an iterable
  • Added g:power() to implement raising a number by a power
  • Added g:range() to allow for integer ranges to be created
  • Changed g:difference() to g:diff() (abbreviation policy enacted for function names)
  • Added g:set() to create a set (unordered, unique collection of objects)
  • Added g:integer(), g:long(), g:float(), and g:double() to support number casting
• Additions to the Gremlin type system
  • Supports iterable as a super type in order to have direct support for lazy evaluation
  • Supports set as an unordered, unique collection of objects
  • Supports integer (1), long (1l), float (1.0), double (1.0d) as different number types
• Print streams can be dynamically set in GremlinScriptContext
• true(), false(), and null() are now keywords—true, false, null
• String concatenation is supported with the + operation
• Range filter support through [1..10] type syntax
• Index of lists starts at 0 instead of 1 as in Gremlin 0.2.2
• Test cases now provide performance statistics
• Removed the ‘show all aspects’ * step (i.e. ./outE/inV/*)
• Allow for the use of assignment and other operations within a path (e.g. ./outE/inV[g:p($x := .)]
• Provided support for OrientDB graph database (main body of work in Blueprints)
• Update to dependency inclusions
  • Distribution includes all supported graph databases in Blueprints (gremlin-*-standalone.jar)
  • Dependency provide <scope>provided</scope>

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Version 0.2.2 (Gremicide — March 7, 2010)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.2.2</version>
</dependency>

• Fixed a bug introduced in 0.2.1 having to do with variables copied from a parent path context
• Added dependency on Neo4j RDF and SAIL SNAPSHOTS
• Added Neo4jSailGraph BETA to the core distribution

Version 0.2.1 (Gremicide — February 25, 2010)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.2.1</version>
</dependency>

• Instance naming convention for Functions changed to FunctionLibrary
• list g:list(object+) is now list g:list(object*)
• Added support for Java 1.6+ JSR 223 ScriptEngine and ScriptEngineFactory
  • Renamed GremlinEngine to GremlinScriptEngine
  • Renamed GremlinEngineFactory to GremlinScriptEngineFactory

Version 0.2 (Gremicide — February 14, 2010)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.2</version>
</dependency>

• Added user defined functions
  • Gremlin and Java defined functions supported
• Added user defined paths
  • Gremlin and Java defined functions supported
• Added .gremlinrc load script
• Added support for manual transaction handling of Neo4j graphs
  • boolean neo4j:start-tx(), boolean neo4j:stop-tx(boolean) added
• Added support for embedded maps and lists
• Added support for JSON encoding and decoding of Gremlin types
  • g:json(object) was removed
  • string g:to-json(object) and object g:from-json(string) added
• Added better support for vertex and edge property indexing
• Added working graph $_g variable and updated graph functions to support it
• Added support for SPARQL queries for SAIL-based graphs
  • list sail:sparql(string) was added
• Added support for Linked Data SAIL for real-time analysis of the Web of Data
• Added support for script loading
  • script gremlin-script.grm
• Added support for JUNG algorithms over Gremlin graphs
• Renamed g:append(object, object+) to g:list(object+)
• Renamed the general graph model to property graph model
  • Moved the model and its implementations to Blueprints
  • Uses Blueprints 0.1
• Various bug fixes and optimizations

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Version 0.1 (XMas Alpha — December 25, 2009)

<dependency>
  <groupId>com.tinkerpop</groupId>
  <artifactId>gremlin</artifactId>
  <version>0.1</version>
</dependency>

• Initial release of the language and virtual machine