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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/gf-tutorial.txt | 52 |
1 files changed, 28 insertions, 24 deletions
diff --git a/doc/gf-tutorial.txt b/doc/gf-tutorial.txt index cbd2c3213..be1f3e8da 100644 --- a/doc/gf-tutorial.txt +++ b/doc/gf-tutorial.txt @@ -662,7 +662,7 @@ The GF system is an implementation of the GF programming language, which in turn is built on the ideas of the GF theory. -The main focus of this tutorial is on using the GF programming language. +The focus of this tutorial is on using the GF programming language. At the same time, we learn the way of thinking in the GF theory. @@ -676,7 +676,7 @@ using the GF system. A GF program is called a **grammar**. -A grammar defines of a language. +A grammar defines a language. From this definition, language processing components can be derived: - **parsing**: to analyse the language @@ -875,8 +875,8 @@ into an internal representation and show the CPU time was consumed, followed by a new prompt: ``` > i HelloEng.gf - - compiling Hello.gf... wrote file Hello.gfc 8 msec - - compiling HelloEng.gf... wrote file HelloEng.gfc 12 msec + - compiling Hello.gf... wrote file Hello.gfo 8 msec + - compiling HelloEng.gf... wrote file HelloEng.gfo 12 msec 12 msec > @@ -1031,8 +1031,8 @@ Application programs, using techniques from #Rchapeight: - spoken language translators - dialogue systems - user interfaces - - localization: parametrize the messages printed by a program - to support different languages + - localization: render the messages printed by a program + in different languages @@ -1386,12 +1386,12 @@ after having worked out #Rchapfour. Semantically indistinguishable ways of expressing a thing. -The ``variants`` construct of GF expresses free variation. For example, +The **variants** construct of GF expresses free variation. For example, ``` - lin Delicious = {s = variants {"delicious" ; "exquisit" ; "tasty"}} ; + lin Delicious = {s = "delicious" | "exquisit" | "tasty"} ; ``` By default, the ``linearize`` command -shows only the first variant from each ``variants`` list; to see them +shows only the first variant from such lists; to see them all, use the option ``-all``: ``` > p "this exquisit wine is delicious" | l -all @@ -1399,14 +1399,21 @@ all, use the option ``-all``: this delicious wine is exquisit ... ``` -Limiting case: an empty variant list + +#NEW + +An equivalent notation for variants is +``` + lin Delicious = {s = variants {"delicious" ; "exquisit" ; "tasty"}} ; +``` +This notation also allows the limiting case: an empty variant list, ``` variants {} ``` It can be used e.g. if a word lacks a certain inflection form. Free variation works for all types in concrete syntax; all terms in -a ``variants`` list must be of the same type. +a variant list must be of the same type. #NEW @@ -1420,7 +1427,7 @@ a ``variants`` list must be of the same type. **Multilingual treebank**: a set of trees with their linearizations in different languages: ``` - > gr -number=2 | tree_bank + > gr -number=2 | l -treebank Is (That Cheese) (Very Boring) quel formaggio è molto noioso @@ -1430,8 +1437,6 @@ linearizations in different languages: quel formaggio è fresco that cheese is fresh ``` -There is also an XML format for treebanks and a set of commands -suitable for regression testing; see ``help tb`` for more details. @@ -1472,7 +1477,7 @@ answer given in another language. ===The "cf" grammar format=== -The grammar ``FoodEng`` could be written in a BNF format as follows: +The grammar ``FoodEng`` can be written in a BNF format as follows: ``` Is. Phrase ::= Item "is" Quality ; That. Item ::= "that" Kind ; @@ -1489,12 +1494,12 @@ The grammar ``FoodEng`` could be written in a BNF format as follows: Very. Quality ::= "very" Quality ; Warm. Quality ::= "warm" ; ``` -The GF system v 2.9 can be used for converting BNF grammars into GF. -BNF files are recognized by the file name suffix ``.cf``: +GF can convert BNF grammars into GF. +BNF files are recognized by the file name suffix ``.cf`` (for **context-free**): ``` > import food.cf ``` -It creates separate abstract and concrete modules. +The compiler creates separate abstract and concrete modules internally. #NEW @@ -1520,7 +1525,7 @@ copy language ``{x x | x <- (a|b)*}`` in GF. GF uses suffixes to recognize different file formats: - Source files: //Modulename//``.gf`` -- Target files: //Modulename//``.gfc`` +- Target files: //Modulename//``.gfo`` Importing generates target from source: @@ -1708,8 +1713,7 @@ A new module can **extend** an old one: Question ; fun QIs : Item -> Quality -> Question ; - Pizza : Kind ; - + Pizza : Kind ; } ``` Parallel to the abstract syntax, extensions can @@ -1875,6 +1879,8 @@ argument. For instance, ``` case e of {...} === table {...} ! e ``` +Since they are familiar to Haskell and ML programmers, they can come out handy +when writing GF programs. #NEW @@ -1916,7 +1922,7 @@ A morphological **paradigm** is a formula telling how a class of words is inflected. From the GF point of view, a paradigm is a function that takes -a **lemma** (**dictionary form**, **citation form**) and +a **lemma** (also known as a **dictionary form**, or a **citation form**) and returns an inflection table. The following operation defines the regular noun paradigm of English: @@ -2741,8 +2747,6 @@ Thus artIndef ++ "apple" ---> "an" ++ "apple" ``` -//Prefix-dependent choice may be deprecated in GF version 3.// - |