LL parser
In computer science, an LL parser is a top-down parser for a subset of context-free languages. It parses the input from Left to right, performing Leftmost derivation of the sentence.
An LL parser is called an LL(k) parser if it uses k tokens of lookahead when parsing a sentence. If such a parser exists for a certain grammar and it can parse sentences of this grammar without backtracking then it is called an LL(k) grammar. LL(k) grammars can generate more languages the higher the number k of lookahead tokens. A corollary of this is that not all context-free languages can be recognized by an LL(k) parser. An LL parser is called an LL(*) parser (an LL-regular parser) if it is not restricted to a finite k tokens of lookahead, but can make parsing decisions by recognizing whether the following tokens belong to a regular language (for example by means of a Deterministic Finite Automaton).
LL grammars, particularly LL(1) grammars, are of great practical interest, as parsers for these grammars are easy to construct, and many computer languages are designed to be LL(1) for this reason. LL parsers are table-based parsers, similar to LR parsers. LL grammars can also be parsed by recursive descent parsers.
Ll
Ll/ll is a digraph which occurs in several natural languages.
English
In English, ll represents the same sound as single l: /l/. The doubling is used to indicate that the preceding vowel is (historically) short, or for etymological reasons, in latinisms (coming from a gemination).
Spanish
Digraph, considered from 1754 to 2010 as the fourteenth letter of the Spanish alphabet because of its representation of a palatal lateral articulation consonant phoneme. (definition by the Royal Academy of the Spanish Language)
However, nowadays most Spanish speakers pronounce ll the same as y (yeísmo). As a result, in most parts of Hispanic America as well as in many regions of Spain, Spanish speakers pronounce it /ʝ/ (voiced palatal fricative), while some other Hispanic Americans (especially Rioplatense speakers, and in Tabasco, Mexico) pronounce it /ʒ/ (voiced postalveolar fricative) or /ʃ/ (voiceless postalveolar fricative).
Shall and will
Shall and will are two of the English modal verbs. They have various uses, including the expression of propositions about the future, in what is usually referred to as the future tense of English.
The traditional prescriptive grammar rule stated that, when expressing pure futurity (without any additional meaning such as desire or command), shall was to be used when the subject was in the first person (I or we), and will in other cases. In practice this rule is commonly not adhered to by any group of English speakers, and many speakers do not differentiate between will and shall when expressing futurity, with the use of will being much more common and less formal than shall. In many specific contexts, however, a distinction still continues.
Shall is widely used in bureaucratic documents, especially documents written by lawyers. Due to heavy misuse, its meaning is vague and the US Government's Plain Language group advises writers not to use the word.
Etymology
The verb shall derives from Old English sceal. Its cognates in other Germanic languages include Old Norse skal, German soll, and Dutch zal; these all represent *skol-, the o-grade of Indo-European *skel-. All of these verbs function as auxiliaries, representing either simple futurity, or necessity or obligation.
Podcasts:
