^^Parsing (a string of a language).

≡ parsing  ≡  syntax analysis  ≡  syntactic analysis  ≡  analisi sintattica

≡ construction history ≡ derivation history

parsing an arithmetic expression;  arithmetic expression parser

e' il caso piu' semplice, archetipico di parsing

es:  2+3*4  deve essere calcolata come 2+(3*4) e non  (2+3)*4

parsing

to transform a string of symbols into a structure (usually parse tree),

according to rules.

An essential operation for working with a language.
Recognizing is one of its functions.
Etimo da "pars orationis" (parte del discorso, part of speech)

parser

chi opera il parsing, uomo o programma.
Di solito i parser non sono scritti a mano, ma bensi' da generatori di parser.

Oss: i "trees" generati dai parser sono "trees-data_structures", legati ma non uguali ai "trees" della matematica, disambigua

Parsing is important because

a derivation usually brings out the "meaning" of the string.

Es. for a computer program, a derivation of the program in the program grammar tells the compiler how the program should be executed.

Dirlo

1. parsing a string of a language
2. parsing a string
3. parsing a language; to parse a language
4. parsing a natural language, parsing a  formal language.
5. Nel caso di linguaggio naturale: parsing di uno scritto o di un parlato.
6. "parsing" e'  comune a linguistica e informatica, with slightly different meanings.

vo: parsing  VS  parser

Come dire "tornire VS tornio-tornitore".

Azione e cosa.

10 parti del discorso della grammatica italiana

nome aggettivo articolo pronome numerale verbo avverbio preposizione congiunzione interiezione

"Parsing" da "pars orationis" (parte del discorso, part of speech)

graverini.net/lezione6x3d.html

recognizer    lexical analysis  Parsing timeline#recognizer ;   wp

recognize whether an arbitrary string belongs to its language or not.
It's one of the functions of a parser.

To describe recognizers, formal language theory uses separate formalisms, known as automata theory.

One of the interesting results of automata theory is that

it is not possible to design a recognizer for certain formal languages.

lexical analysis  ≡  lexing  ≡  tokenization  
made by   lexer  ≡  tokenizer

in computer science is the process of converting

• from a string,  es  a computer program, a web page
• to     a sequence of tokens ≡ strings with an assigned and thus identified meaning.

A lexer is generally combined with a parser, which together analyze the syntax of the string. 

wp/Lexical_analysis

Links librosito

1. Parsing timeline. | parser_(Parsing timeline)
2. Python BNF.
   • lexical definition operates on the individual characters of the input source
   • syntax definition operates on the stream of tokens generated by the lexical analysis
3. Linguistica. Poiche' "parsing" e' tema comune a linguistica e programmazione.
4. vo: Sintassi. | Linguaggio: grammatica, semantica, sintassi.

Links wp

1. wp/Parsing | wp/Parse_tree | wp/Abstract_syntax_tree
2. wp/Lexer, Lexical_analysis
   • stackoverflow/what-is-the-difference-between-a-token-and-a-lexeme
3. wp/Garden-path_sentence  "The old man the boat."
4. wp/Part_of_speech | wp/Parti_del_discorso della grammatica classica.
5. Compiler

Links

1. https://www.engr.mun.ca/~theo/Misc/exp_parsing.htm 
   Parsing Expressions by Recursive Descent
   Theodore Norvell (C) 1999 with updates later on.

Talk