-- GF help file updated for GF 2.0, 24/3/2004.
-- *: Commands and options marked with * are not yet implemented.
--
-- Each command has a long and a short name, options, and zero or more
-- arguments. Commands are sorted by functionality. The short name is
-- given first.

-- Type "h -all" for full help file, "h <CommandName>" for full help on a command.  

-- commands that change the state

i,  import: i File
      Reads a grammar from File and compiles it into a GF runtime grammar.
      Files "include"d in File are read recursively, nubbing repetitions.
      If a grammar with the same language name is already in the state,
      it is overwritten - but only if compilation succeeds. 
      The grammar parser depends on the file name suffix:
        .gf    normal GF source
        .gfc   canonical GF
        .gfr   precompiled GF resource  
        .gfcm  multilingual canonical GF
        .ebnf  Extended BNF format
        .cf    Context-free (BNF) format
  options:
      -old          old: parse in GF<2.0 format (not necessary)
      -v            verbose: give lots of messages 
      -s            silent: don't give error messages
      -opt          perform branch-sharing optimization
      -src          source: ignore precompiled gfc and gfr files
      -retain       retain operations: read resource modules (needed in comm cc) 
      -nocf         don't build context-free grammar (thus no parser)
      -nocheckcirc  don't eliminate circular rules from CF 
      -cflexer      build an optimized parser with separate lexer trie
  flags:
      -abs          set the name used for abstract syntax (with -old option)
      -cnc          set the name used for concrete syntax (with -old option)
      -res          set the name used for resource (with -old option)
      -path         use the (colon-separated) search path to find modules
  examples:
      i English.gf                      -- ordinary import of Concrete
      i -retain german/ParadigmsGer.gf  -- import of Resource to test
      
* rl, remove_language: rl Language
      Takes away the language from the state.

e,  empty: e
      Takes away all languages and resets all global flags.

sf, set_flags: sf Flag*
      The values of the Flags are set for Language. If no language
      is specified, the flags are set globally.
  examples:
      sf -nocpu     -- stop showing CPU time
      sf -lang=Swe  -- make Swe the default concrete

s,  strip: s
      Prune the state by removing source and resource modules.

-- commands that give information about the state

pg, print_grammar: pg
      Prints the actual grammar (overridden by the -lang=X flag).
      The -printer=X flag sets the format in which the grammar is
      written.
      N.B. since grammars are compiled when imported, this command
      generally does not show the grammar in the same format as the
      source. In particular, the -printer=latex is not supported. 
      Use the command tg -printer=latex File to print the source 
      grammar in LaTeX.
  options:
      -utf8  apply UTF8-encoding to the grammar
  flags: 
      -printer
      -lang
  examples:
      pg -printer=cf  -- show the context-free skeleton

pm, print_multigrammar: pm
      Prints the current multilingual grammar in .gfcm form.
      (Automatically executes the strip command (s) before doing this.)
  examples:
      pm | wf Letter.gfcm  -- print the grammar into the file Letter.gfcm

po, print_options: po
      Print what modules there are in the state. Also
      prints those flag values in the current state that differ from defaults.

pl, print_languages: pl
      Prints the names of currently available languages.

pi, print_info: pi Ident
      Prints information on the identifier.

-- commands that execute and show the session history

eh, execute_history: eh File
      Executes commands in the file.

ph, print_history; ph
      Prints the commands issued during the GF session.
      The result is readable by the eh command.
  examples:
      ph | wf foo.hist"  -- save the history into a file

-- linearization, parsing, translation, and computation

l,  linearize: l PattList? Tree
      Shows all linearization forms of Tree by the actual grammar
      (which is overridden by the -lang flag). 
      The pattern list has the form [P, ... ,Q] where P,...,Q follow GF 
      syntax for patterns. All those forms are generated that match with the
      pattern list. Too short lists are filled with variables in the end.
      Only the -table flag is available if a pattern list is specified.
      HINT: see GF language specification for the syntax of Pattern and Term.
      You can also copy and past parsing results.
  options:  
      -table   show parameters
      -struct  bracketed form
      -record  record, i.e. explicit GF concrete syntax term
      -all     show all forms and variants
  flags:
      -lang    linearize in this grammar
      -number  give this number of forms at most
      -unlexer filter output through unlexer
  examples:
      l -lang=Swe -table  -- show full inflection table in Swe

p,  parse: p String
      Shows all Trees returned for String by the actual
      grammar (overridden by the -lang flag), in the category S (overridden
      by the -cat flag).
  options:
      -n       non-strict: tolerates morphological errors
      -ign     ignore unknown words when parsing
      -raw     return context-free terms in raw form
      -v       verbose: give more information if parsing fails
      -new     use an experimental method (GF 2.0; sometimes very good)
  flags:
      -cat     parse in this category
      -lang    parse in this grammar
      -lexer   filter input through this lexer
      -parser  use this context-free parsing method
      -number  return this many results at most
  examples:
      p -cat=S -new "jag är gammal"   -- print an S with the new method

tt, test_tokenizer: tt String
      Show the token list sent to the parser when String is parsed.
      HINT: can be useful when debugging the parser.
  flags: 
     -lexer    use this lexer
  examples:
     tt -lexer=codelit "2*(x + 3)"  -- a favourite lexer for program code

cc, compute_concrete: cc Term
      Compute a term by concrete syntax definitions. Uses the topmost
      resource module (the last in listing by command po) to resolve 
      constant names. 
      N.B. You need the flag -retain when importing the grammar, if you want 
      the oper definitions to be retained after compilation; otherwise this
      command does not expand oper constants.
      N.B.' The resulting Term is not a term in the sense of abstract syntax,
      and hence not a valid input to a Tree-demanding command.
  flags:
     -res      use another module than the topmost one
  examples:
     cc -res=ParadigmsFin (nLukko "hyppy")   -- inflect "hyppy" with nLukko

so, show_operations: so Type
      Show oper operations with the given value type. Uses the topmost 
      resource module to resolve constant names. 
      N.B. You need the flag -retain when importing the grammar, if you want 
      the oper definitions to be retained after compilation; otherwise this
      command does not find any oper constants.
      N.B.' The value type may not be defined in a supermodule of the
      topmost resource. In that case, use appropriate qualified name.
  flags:
     -res      use another module than the topmost one
  examples:
     so -res=ParadigmsFin ResourceFin.N  -- show N-paradigms in ParadigmsFin

t,  translate: t Lang Lang String
      Parses String in Lang1 and linearizes the resulting Trees in Lang2.
  flags:
      -cat
      -lexer
      -parser
  examples:
      t Eng Swe -cat=S "every number is even or odd"

gr, generate_random: gr Tree?
      Generates a random Tree of a given category. If a Tree
      argument is given, the command completes the Tree with values to
      the metavariables in the tree. 
  flags:
      -cat     generate in this category
      -lang    use the abstract syntax of this grammar
      -number  generate this number of trees (not impl. with Tree argument)
      -depth   use this number of search steps at most
  examples:
      gr -cat=Query            -- generate in category Query
      gr (PredVP ? (NegVG ?))  -- generate a random tree of this form
      gr -cat=S -tr | l        -- gererate and linearize

gt, generate_trees: gt Tree?
      Generates all trees up to a given depth. If the depth is large,
      a small -alts is recommended. If a Tree argument is given, the
      command completes the Tree with values to the metavariables in
      the tree.
  options:
      -metas   also return trees that include metavariables
  flags:
      -depth   generate to this depth (default 3)
      -alts    take this number of alternatives at each branch (default unlimited)
      -cat     generate in this category
      -lang    use the abstract syntax of this grammar
      -number  generate (at most) this number of trees
  examples:
      gt -depth=10 -cat=NP     -- generate all NP's to depth 10 
      gt (PredVP ? (NegVG ?))  -- generate all trees of this form
      gt -cat=S -tr | l        -- gererate and linearize

ma, morphologically_analyse: ma String
      Runs morphological analysis on each word in String and displays
      the results line by line.
  options:
      -short   show analyses in bracketed words, instead of separate lines
  flags:
      -lang
  examples:
      wf Bible.txt | ma -short | wf Bible.tagged  -- analyse the Bible


-- elementary generation of Strings and Trees

ps, put_string: ps String
      Returns its argument String, like Unix echo.
      HINT. The strength of ps comes from the possibility to receive the 
      argument from a pipeline, and altering it by the -filter flag.
  flags:
      -filter  filter the result through this string processor 
      -length  cut the string after this number of characters
  examples:
      gr -cat=Letter | l | ps -filter=text -- random letter as text

pt, put_tree: pt Tree
      Returns its argument Tree, like a specialized Unix echo.
      HINT. The strength of pt comes from the possibility to receive 
      the argument from a pipeline, and altering it by the -transform flag.
  flags:
      -transform   transform the result by this term processor
      -number      generate this number of terms at most
  examples:
      p "zero is even" | pt -transform=solve  -- solve ?'s in parse result


* st, show_tree: st Tree
      Prints the tree as a string. Unlike pt, this command cannot be
      used in a pipe to produce a tree, since its output is a string.
  flags:
      -printer     show the tree in a special format (-printer=xml supported)


-- subshells

es, editing_session: es
      Opens an interactive editing session.
      N.B. Exit from a Fudget session is to the Unix shell, not to GF. 
  options:
      -f Fudget GUI (necessary for Unicode; only available in X Window System)

ts, translation_session: ts
      Translates input lines from any of the actual languages to all other ones.
      To exit, type a full stop (.) alone on a line.
      N.B. Exit from a Fudget session is to the Unix shell, not to GF. 
      HINT: Set -parser and -lexer locally in each grammar.
  options:
      -f    Fudget GUI (necessary for Unicode; only available in X Windows)
      -lang prepend translation results with language names
  flags:
      -cat    the parser category
  examples:
      ts -cat=Numeral -lang  -- translate numerals, show language names

tq, translation_quiz: tq Lang Lang
      Random-generates translation exercises from Lang1 to Lang2,
      keeping score of success.
      To interrupt, type a full stop (.) alone on a line.
      HINT: Set -parser and -lexer locally in each grammar.
  flags:
      -cat
  examples:
      tq -cat=NP TestResourceEng TestResourceSwe  -- quiz for NPs

tl, translation_list: tl Lang Lang Int
      Random-generates a list of Int translation exercises from Lang1 to Lang2.
      HINT: use wf to save the exercises in a file.
  flags:
      -cat
  examples:
      tl -cat=NP TestResourceEng TestResourceSwe  -- quiz list for NPs

mq, morphology_quiz: mq
      Random-generates morphological exercises,
      keeping score of success.
      To interrupt, type a full stop (.) alone on a line.
      HINT: use printname judgements in your grammar to
      produce nice expressions for desired forms.
  flags:
      -cat
      -lang
  examples:
      mq -cat=N -lang=TestResourceSwe  -- quiz for Swedish nouns

ml, morphology_list: ml Int
      Random-generates a list of Int morphological exercises,
      keeping score of success.
      HINT: use wf to save the exercises in a file.
  flags:
      -cat
      -lang
  examples:
      ml -cat=N -lang=TestResourceSwe  -- quiz list for Swedish nouns


-- IO related commands

rf, read_file: rf File
      Returns the contents of File as a String; error if File does not exist.

wf, write_file: wf File String
      Writes String into File; File is created if it does not exist.
      N.B. the command overwrites File without a warning.

af, append_file: af File
      Writes String into the end of File; File is created if it does not exist.

* tg, transform_grammar: tg File
      Reads File, parses as a grammar, 
      but instead of compiling further, prints it. 
      The environment is not changed. When parsing the grammar, the same file
      name suffixes are supported as in the i command.
      HINT: use this command to print the grammar in 
      another format (the -printer flag); pipe it to wf to save this format.
  flags:
      -printer  (only -printer=latex supported currently)

* cl, convert_latex: cl File
      Reads File, which is expected to be in LaTeX form.
      Three environments are treated in special ways:
        \begGF    - \end{verbatim}, which contains GF judgements,
        \begTGF   - \end{verbatim}, which contains a GF expression (displayed)
        \begInTGF - \end{verbatim}, which contains a GF expressions (inlined).
      Moreover, certain macros should be included in the file; you can
      get those macros by applying 'tg -printer=latex foo.gf' to any grammar
      foo.gf. Notice that the same File can be imported as a GF grammar,
      consisting of all the judgements in \begGF environments.
      HINT: pipe with 'wf Foo.tex' to generate a new Latex file.

sa, speak_aloud: sa String
      Uses the Flite speech generator to produce speech for String.
      Works for American English spelling. 
  examples:
    h | sa              -- listen to the list of commands
    gr -cat=S | l | sa  -- generate a random sentence and speak it aloud

h, help: h Command?
      Displays the paragraph concerning the command from this help file.
      Without the argument, shows the first lines of all paragraphs.
  options
       -all  show the whole help file
  examples:
       h print_grammar  -- show all information on the pg command

q, quit: q
      Exits GF.
      HINT: you can use 'ph | wf history' to save your session.

!, system_command: ! String
      Issues a system command. No value is returned to GF.
   example:
      ! ls


-- Flags. The availability of flags is defined separately for each command.

-cat, category in which parsing is performed.
      The default is S.

-depth, the search depth in e.g. random generation.
      The default depends on application.

-filter, operation performed on a string. The default is identity.
    -filter=identity     no change
    -filter=erase        erase the text
    -filter=take100      show the first 100 characters
    -filter=length       show the length of the string
    -filter=text         format as text (punctuation, capitalization)
    -filter=code         format as code (spacing, indentation)

-lang, grammar used when executing a grammar-dependent command.
       The default is the last-imported grammar.

-language, voice used by Festival as its --language flag in the sa command. 
       The default is system-dependent. 

-length, the maximum number of characters shown of a string. 
       The default is unlimited.

-lexer, tokenization transforming a string into lexical units for a parser.
       The default is words.
    -lexer=words         tokens are separated by spaces or newlines
    -lexer=literals      like words, but GF integer and string literals recognized
    -lexer=vars          like words, but "x","x_...","$...$" as vars, "?..." as meta
    -lexer=chars         each character is a token
    -lexer=code          use Haskell's lex
    -lexer=text          with conventions on punctuation and capital letters
    -lexer=codelit       like code, but treat unknown words as string literals
    -lexer=textlit       like text, but treat unknown words as string literals
    -lexer=codeC         use a C-like lexer

-number, the maximum number of generated items in a list. 
       The default is unlimited.

-parser, Context-free    parsing algorithm. The default is chart.
    -parser=earley       Earley algorithm
    -parser=chart        bottom-up chart parser

-printer, format in which the grammar is printed. The default is gfc.
    -printer=gfc            GFC grammar
    -printer=gf             GF grammar
    -printer=old            old GF grammar
    -printer=cf             context-free grammar
   *-printer=happy          source file for Happy parser generator
    -printer=srg            speech recognition grammar
    -printer=haskell        abstract syntax in Haskell, with transl to/from GF
    -printer=morpho         full-form lexicon, long format
   *-printer=latex          LaTeX file (for the tg command)
    -printer=fullform       full-form lexicon, short format
   *-printer=xml            XML: DTD for the pg command, object for st
    -printer=old            old GF: file readable by GF 1.2

-startcat, like -cat, but used in grammars (to avoid clash with keyword cat)

-transform, transformation performed on a syntax tree. The default is identity.
    -transform=identity  no change
    -transform=compute   compute by using definitions in the grammar
    -transform=typecheck return the term only if it is type-correct
    -transform=solve     solve metavariables as derived refinements
    -transform=context   solve metavariables by unique refinements as variables
    -transform=delete    replace the term by metavariable

-unlexer, untokenization transforming linearization output into a string.
       The default is unwords.
    -unlexer=unwords     space-separated token list (like unwords)
    -unlexer=text        format as text: punctuation, capitals, paragraph <p>
    -unlexer=code        format as code (spacing, indentation)
    -unlexer=textlit     like text, but remove string literal quotes
    -unlexer=codelit     like code, but remove string literal quotes
    -unlexer=concat      remove all spaces
    -unlexer=bind        like identity, but bind at "&+"

-- *: Commands and options marked with * are not yet implemented.