add_indent(+Indent:positive_integer)//

 alphanum(?Code:code)//

 dcg_atom(:Dcg_1, ?Atom:atom)//

This meta-DCG rule handles the translation between the word and the character level of parsing/generating.

Typically, grammar A specifies how words can be formed out of characters. A character is a code, and a word is a list of codes. Grammar B specifies how sentences can be built out of words. Now the word is an atom, and the sentences in a list of atoms.

This means that at some point, words in grammar A, i.e. lists of codes, need to be translated to words in grammar B, i.e. atoms.

This is where dcg_atom//2 comes in. We illustrate this with a schematic example:

sentence([W1,...,Wn]) -->
  word2(W1),
  ...,
  word2(Wn).

word2(W) -->
  dcg_atom(word1, W).

word1([C1, ..., Cn]) -->
  char(C1),
  ...,
  char(Cn).

throws

- instantiation_error

- type_error

 dcg_between(+Low:nonneg, +High:nonneg)//

 dcg_between(+Low:nonneg, +High:nonneg, ?Code:nonneg)//

 dcg_boolean(+Boolean:boolean)// is det

dcg_boolean(-Boolean:boolean)// is det

 dcg_call(:Dcg_0)//

 dcg_call(:Dcg_1, ?Arg1)//

 dcg_call(:Dcg_2, ?Arg1, ?Arg2)//

 dcg_call(:Dcg_3, ?Arg1, ?Arg2, ?Arg3)//

 dcg_call(:Dcg_4, ?Arg1, ?Arg2, ?Arg3, ?Arg4)//

 dcg_call(:Dcg_5, ?Arg1, ?Arg2, ?Arg3, ?Arg4, ?Arg5)//

See also

- call/[1-8]

 dcg_peek(+Length:nonneg)//

 dcg_pp_boolean(+Boolean:boolean)// is det

 dcg_string(:Dcg_1, ?String)//

 dcg_with_output_to(:Dcg_0) is nondet

 dcg_with_output_to(+Sink, :Dcg_0) is nondet

 default(:Dcg_0, ?Default_0)//

 digit_weight(?Weight:between(0,9))//

 ellipsis(+Original:text, +MaxLength:beteen(2,inf))// is det

Arguments:

MaxLength

- The maximum length of the generated ellipsed string.

 error_location(+SyntaxError:compound, +Input:list(code)) is det

 error_location(+SyntaxError:compound, +Input:list(code), +Length:nonneg) is det

 indent(+Indent:nonneg)// is det

 must_see(:Dcg_0)//

 must_see_code(+Code, :Skip_0)//

 nl// is det

 nonblank//

Wrapper around nonblank//1 from library(dcg/basics).

 nonblanks//

 parsing// is semidet

Succeeds if currently parsing a list of codes (rather than generating a list of codes).

 remainder_as_atom(-Atom:atom)// is det

 remainder_as_string(-Remainder:string)// is det

 string_phrase(:Dcg_0, ?String) is nondet

 string_phrase(:Dcg_0, +String1, ?String2) is nondet

 tab(+N:nonneg)// is det

 term(+Term)// is det

 thousands(+N:integer)// is det

 ws// is det

 ...//

 ...(-Codes:list(code))//

Wrapper around string//1.

 alpha//

 alpha(?Code:code)//

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 ...(Arg1, Arg2)

 atom_phrase(Arg1, Arg2)

 atom_phrase(Arg1, Arg2, Arg3)

 dcg_between(Arg1, Arg2, Arg3, Arg4, Arg5)

 dcg_call(Arg1, Arg2, Arg3, Arg4)

 dcg_call(Arg1, Arg2, Arg3, Arg4, Arg5)

 dcg_call(Arg1, Arg2, Arg3, Arg4, Arg5, Arg6)

 dcg_call(Arg1, Arg2, Arg3, Arg4, Arg5, Arg6, Arg7)

 dcg_call(Arg1, Arg2, Arg3, Arg4, Arg5, Arg6, Arg7, Arg8)

 dcg_char(Arg1, Arg2, Arg3)

 dcg_with_output_to(Arg1, Arg2)

 error_location(Arg1, Arg2, Arg3)

 string_phrase(Arg1, Arg2, Arg3)

 white(Arg1, Arg2)

 whites(Arg1, Arg2)

 blank(Arg1, Arg2)

 blanks(Arg1, Arg2)

 nonblank(Arg1, Arg2, Arg3)

 nonblanks(Arg1, Arg2, Arg3)

 blanks_to_nl(Arg1, Arg2)

 string(Arg1, Arg2, Arg3)

 string_without(Arg1, Arg2, Arg3, Arg4)

 alpha_to_lower(Arg1, Arg2, Arg3)

 digits(Arg1, Arg2, Arg3)

 digit(Arg1, Arg2, Arg3)

 integer(Arg1, Arg2, Arg3)

 float(Arg1, Arg2, Arg3)

 number(Arg1, Arg2, Arg3)

 xdigits(Arg1, Arg2, Arg3)

 xdigit(Arg1, Arg2, Arg3)

 xinteger(Arg1, Arg2, Arg3)

 prolog_var_name(Arg1, Arg2, Arg3)

 csym(Arg1, Arg2, Arg3)

 eol(Arg1, Arg2)

 eos(Arg1, Arg2)

 remainder(Arg1, Arg2, Arg3)

 atom(Arg1, Arg2, Arg3)