GLOSSARY

Bookkeeping Keeping track of status of a system.

Buggy A program or a system with errors.

Compiler-compiler A program which, given specification of a language in terms of its grammar, generates major portions of its compiler modules. Usually the parser is generated.

Conflicts Alternate paths in the FSM of the parser model, which cannot be decided unless additional information is supplied.

Dangling Undecided.

Deterministic FSM is one in which each arc in the state diagram is associated with a well-defined set of input symbols, specifically there are no e transitions.

Disambiguation Resolution of ambiguities.

Double-precision refers to a computer representation of real numbers as floating-point numbers in mantissa/exponent form, where mantissa size is 53-bits signed 2's complement and exponent is 11-bits biased unsigned integer.

GLR-parser Generalized LR parser, which explores in parallel with the alternate paths in the FSM of the parser in order to achieve higher speed.

Item set A set of items, specifically corresponding to a state in the parser FSM.

Left-production is generated by a grammar rule by appending symbols on the LHS of the sentential form.

Look-ahead is a symbol that would be scanned next at the current stage of parsing, but is actually not yet read.

Min-term is a Boolean term obtained by AND of all the variables – either in direct or in negated form – making up a Boolean expression.

Nullable-NT is a non-terminal meta-variable in a grammar, which can be replaced by a null symbol by some grammar rule.

Parse-stack works along with the FSM of the parser in the PDA model.

Parser-PDA See parse-stack.

Reduce-reduce Conflict occurs when two different reduce operations are indicated within the same item set.

Reduction Replacing a handle by a Non-Terminal on the parse-stack, following a particular grammar rule.

Re-entrant Routine allows its second and subsequent invocations even when the first invocation is not completed, without any interference between the active invocations.

Right-context Symbols on the RHS of the scanning point, which provide a context for the parsing decisions, especially for conflict resolution.

Right-production is generated by a grammar rule by appending symbols on the RHS of the sentential form.

Single-precision Refers to a computer representation of real numbers as floating-point numbers in mantissa/exponent form, where mantissa size is 24-bits signed 2's complement and exponent is 8-bits biased unsigned integer.

State-stack is possibly a separate stack in the PDA of the parser, where the states of the FSM are saved as the parsing proceeds.

Sum-of-products form of Boolean expression is formed by AND-terms being OR’ed together, for example x’y + xy’.

Table-driven parser is one in which the state transition information is stored in one or more tables. This allows the basic parser program to be used with any valid grammar, just by changing the tables.

Uncover A state occurs when a reduction takes place and a handle is replaced by a Non-Terminal.

Value-stack is possibly a separate stack in the PDA of the parser, where the attribute values are saved as the parsing proceeds.