jast, a JavaScript parser, AST, and tools

Credit to UglifyJS by mishoo for the parser base. jast is released under the modified BSD license.

AST Definition

Each AST node is a JSON hash with the property "type" corresponding to the node type ("script-context", "sub-op-expr", etc) and the property "ln" corresponding to line number. Each node has properties about the node as described below:

Contexts

• script-context: {Array stats}
• closure-context: {String name, Array<String> args, Array stats}

Literals

• num-literal: {Number value}
• str-literal: {String value}
• obj-literal: {Array<{String value, node expr}> props}
• array-literal: {Array<node> exprs}
• undef-literal: {}
• null-literal: {}
• boolean-literal: {Boolean value}
• func-literal: {node closure}
• regex-literal: {String expr, String flags}

Operations

• num-op-expr: {node expr}
• neg-op-expr: {node expr}
• not-op-expr: {node expr}
• bit-not-op-expr: {node expr}
• typeof-op-expr: {node left, node right}
• void-op-expr: {node left, node right}
• lt-op-expr: {node left, node right}
• lte-op-expr: {node left, node right}
• gt-op-expr: {node left, node right}
• gte-op-expr: {node left, node right}
• eq-op-expr: {node left, node right}
• eqs-op-expr: {node left, node right}
• neq-op-expr: {node left, node right}
• neqs-op-expr: {node left, node right}
• add-op-expr: {node left, node right}
• sub-op-expr: {node left, node right}
• mul-op-expr: {node left, node right}
• div-op-expr: {node left, node right}
• mod-op-expr: {node left, node right}
• lsh-op-expr: {node left, node right}
• rsh-op-expr: {node left, node right}
• bit-and-op-expr: {node left, node right}
• bit-or-op-expr: {node left, node right}
• bit-xor-op-expr: {node left, node right}
• or-op-expr: {node left, node right}
• and-op-expr: {node left, node right}
• instanceof-op-expr: {node left, node right}
• in-op-expr: {node left, node right}
• seq-op-expr: {node left, node right}

Expressions

• num-op-expr: {node expr}
• neg-op-expr: {node expr}
• not-op-expr: {node expr}
• bit-not-op-expr: {node expr}
• typeof-op-expr: {node left, node right}
• void-op-expr: {node left, node right}
• lt-op-expr: {node left, node right}
• lte-op-expr: {node left, node right}
• gt-op-expr: {node left, node right}
• gte-op-expr: {node left, node right}
• eq-op-expr: {node left, node right}
• eqs-op-expr: {node left, node right}
• neq-op-expr: {node left, node right}
• neqs-op-expr: {node left, node right}
• add-op-expr: {node left, node right}
• sub-op-expr: {node left, node right}
• mul-op-expr: {node left, node right}
• div-op-expr: {node left, node right}
• mod-op-expr: {node left, node right}
• lsh-op-expr: {node left, node right}
• rsh-op-expr: {node left, node right}
• bit-and-op-expr: {node left, node right}
• bit-or-op-expr: {node left, node right}
• bit-xor-op-expr: {node left, node right}
• or-op-expr: {node left, node right}
• and-op-expr: {node left, node right}
• instanceof-op-expr: {node left, node right}
• in-op-expr: {node left, node right}
• seq-op-expr: {node left, node right}
• this-expr: {}
• call-expr: {node expr, Array<node> args}
• new-expr: {node constructor, Array<node> args}
• if-expr: {node expr, node thenExpr, node elseExpr}
• scope-ref-expr: {String value}
• static-ref-expr: {node base, String value}
• dyn-ref-expr: {node base, node index}
• static-method-call-expr: {node base, String value, Array<node> args}
• dyn-method-call-expr: {node base, node index, Array<node> args}
• scope-delete-expr: {String value}
• static-delete-expr: {node base, String value}
• dyn-delete-expr: {node base, node index}
• scope-assign-expr: {String value, node expr}
• static-assign-expr: {node base, String value, node expr}
• dyn-assign-expr: {node base, node index, node expr}
• scope-inc-expr: {Boolean pre, Number inc, String value}
• static-inc-expr: {Boolean pre, Number inc, node base, String value}
• dyn-inc-expr: {Boolean pre, Number inc, node base, node index}

Statements

• block-stat: {Array<node> stats}
• expr-stat: {node expr}
• ret-stat: {node expr}
• if-stat: {node expr, node thenStat, node elseStat}
• while-stat: {node expr, node stat}
• do-while-stat: {node expr, node stat}
• for-stat: {node init, node expr, node step, node stat}
• for-in-stat: {Boolean isvar, String value, node expr, node stat}
• switch-stat: {node expr, Array<{node match, node stat}> cases}
• throw-stat: {node expr}
• try-stat: {node tryStat, {String value, node stat} catchBlock, node finallyStat}
• var-stat: {Array<{String value, node expr}> vars}
• defn-stat: {node closure}
• label-stat: {String name, node stat}
• break-stat: {String label}
• continue-stat: {String label}