Description: Documentation

## function build_highlight_table

### Synopsis

build_highlight_table

### Usage

Void build_highlight_table (String n);

### Description

This function builds a DFA table for the enhanced syntax highlighting scheme specified for the syntax table specified by the name n . This must be called before any syntax highlighting will be done for that syntax table.

### See also

create_syntax_table , use_syntax_table , define_highlight_rule , enable_highlight_cache

### See also

WANT_SYNTAX_HIGHLIGHT , USE_ANSI_COLORS

## function create_syntax_table

### Synopsis

create_syntax_table

### Usage

Void create_syntax_table (String name);

### Description

This the purpose of this function is to create a new syntax table with the name specified by name . If the table already exists, this function does nothing.

### See also

define_syntax , use_syntax_table , define_keywords

## function define_highlight_rule

### Synopsis

define_highlight_rule

### Usage

Void define_highlight_rule (String rule, String color, String n);

### Description

This function adds an enhanced highlighting rule to the syntax table specified by the name n . The rule is described as a regular expression by the string rule , and the associated color is given by the string color , in the same format as is passed to set_color . For example:

            create_syntax_table ("demo");
            define_highlight_rule ("[A-Za-z][A-Za-z0-9]*", "keyword", "demo");
            define_highlight_rule ("//.*$", "comment", "demo");
            build_highlight_table ("demo");

causes a syntax table to be defined in which any string of alphanumeric characters beginning with an alphabetic is highlighted in keyword color, and anything after "//" on a line is highlighted in comment color. The regular expression syntax understands character classes like [a-z] and [^a-z0-9] , parentheses, + , * , ? , | and . . Any metacharacter can be escaped using a backslash so that it can be used as a normal character, but beware that due to the syntax of S-Lang strings the backslash has to be doubled when specified as a string constant. For example:

            define_highlight_rule ("^[ \t]*\\*+[ \t].*$", "comment", "C");

defines any line beginning with optional whitespace, then one or more asterisks, then more whitespace to be a comment. Note the doubled backslash before the * . Note also that build_highlight_table must be called before the syntax highlighting can take effect.

### See also

create_syntax_table , use_syntax_table , build_highlight_table

### See also

WANT_SYNTAX_HIGHLIGHT , USE_ANSI_COLORS

## function define_keywords_n

### Synopsis

define_keywords_n

### Usage

String define_keywords_n (String table, String kws, Integer len, Integer n);

### Description

This function is used to define a set of keywords that will be color syntax highlighted in the keyword color associated with the table specified by n . The first parameter, table , specifies which syntax table is to be used for the definition. The second parameter, kws , is a string that is the concatenation of keywords of length specified by the last parameter len . The list of keywords specified by kws must be in alphabetic order. The function returns the previous list of keywords of length len . For example, C mode uses the statement

            () = define_keywords_n ("C", "asmforintnewtry", 3, 0);

to define the four three-letter keywords asm , for , int , new , and try . Note that in the above example, the return value is not used.

### See also

define_syntax , set_color

### See also

WANT_SYNTAX_HIGHLIGHT , USE_ANSI_COLORS

## function define_syntax

### Synopsis

define_syntax

### Usage

Void define_syntax (..., Integer type, String name);

### Description

This function adds a syntax entry to the table specified by the last parameter name . The actual number of parameters vary according to the next to the last parameter type . If type is '"' or '\'' , a string or character delimiter syntax is defined. In this case, define_syntax only takes three parameters where the first parameter is an integer that represents the character for which the syntax is to be applied. Similarly, if type is '\\' , then a quote syntax is defined and again define_syntax only takes three parameters where the first parameter is an integer that represents the character for which the syntax is to be applied. A quote character is one in which the syntax of the following character is not treated as special. If type is '(' , then define_syntax takes four parameters where the first two parameters are strings that represent a matching set of delimiters. The first string contains the set of opening delimiters and the second string specifies the set of closing delimiters that match the first set. If a character from the closing set is entered into the buffer, the corresponding delimiter from the opening set will be blinked. For example, if the C language syntax table is called "C" , then one would use

            define_syntax ("([{", ")]}", '(', "C");

to declare the matching delimiter set. Note that the order of the characters in the two strings must correspond. That is, the above example says that '(' matches ')' and so on. If type is '%' , a comment syntax is defined. As in the previous case, define_syntax takes four parameters where there first two parameters are strings that represent the begin and end comment delimiters. If the comment syntax is such that the comment ends at the end of a line, the second string must either be the empty string, "" , or a newline "\n" . In the current implementation, at most the begin and end comment strings can consist of at most two characters. If type is '+' , the first parameter is a string whose characters are given the operator syntax. If type is ',' , the first parameter is a string composed of characters that are condered to be delimiters. If type is '0', the first parameter is a string composed of characters that make up a number. If type is < , the first parameter is a string whose successive characters form begin and end keyword highlight directives. Finally, if type is '#' , the first parameter is an integer whose value corresponds to the character used to begin preprocessor lines. As an example, imagine a language in which the dollar sign character $ is used as a string delimiter, the backward quote character ` is used as a quote character, comments begin with a semi-colon and end at the end of a line, and the characters '<' and '>' form matching delimiters. The one might use

            create_syntax_table ("strange");
            define_syntax ('$',        '"',  "strange");
            define_syntax ('`',        '\\', "strange");
            define_syntax (";", "",    '%',  "strange");
            define_syntax ("<", ">",   '(',  "strange");

to create a syntax table called "strange" and define the syntax entries for appropriate this example.

### See also

create_syntax_table , use_syntax_table , find_matching_delimiter

### See also

BLINK

## function enable_highlight_cache

### Synopsis

enable_highlight_cache

### Usage

Void enable_highlight_cache (String file, String n);

### Description

This function enables caching of the DFA table for the enhanced syntax highlighting scheme belonging to the syntax table specified by the name n . This should be called before any calls to define_highlight_rule or to build_highlight_table . The parameter file specifies the name of the file (stored in the directory set by the set_highlight_cache_dir function) which should be used as a cache. For example, in cmode.sl one might write

            enable_highlight_cache ("cmode.dfa", "C");

to enable caching of the DFA. If caching were not enabled for C mode, the DFA would take possibly a couple of seconds to compute every time Jed was started. Transferring cache files between different computers is theoretically possible but not recommended. Transferring them between different versions of Jed is not guaranteed to work.

### See also

create_syntax_table , use_syntax_table , define_highlight_rule , build_highlight_table

### See also

WANT_SYNTAX_HIGHLIGHT , USE_ANSI_COLORS

## function parse_to_point

### Synopsis

parse_to_point

### Usage

Integer parse_to_point ();

### Description

This function attempts to determine the syntactic context of the current editing point. That is, it tries to determine whether or not the current point is in a comment, a string, or elsewhere. It returns:

            -2   In a comment
            -1   In a string or a character
             0   Neither of the above

Note: This routine is rather simplistic since it makes the assumption that the character at the beginning of the current line is not in a comment nor is in a string.

### See also

define_syntax , find_matching_delimiter

## function set_fortran_comment_chars

### Synopsis

Specify characters for fortran-like comments

### Usage

Void set_fortran_comment_chars (String_Type table, String_Type list

### Description

This function may be used to specify the set of characters that denote fortran style comments. The first parameter table is the name of a previously defined syntax table, and list denotes the set of characters that specify the fortran-style comment. The string list is simply a set of characters and may include character ranges. If the first character of list is '^' , then the meaning is that only those characters that do not specify fortran sytle comments are included in the list.

### Example

Fortran mode uses the following:

         set_fortran_comment_chars ("FORTRAN", "^0-9 \t\n");

This means that if any line that begins with any character except the characters 0 to 9 , the space, tab, and newline characters will denote a comment.

### Notes

The usefulness of this function is not limited to fortran modes. In fact, many languages have fortran-style comments. This function is meaningful only if the syntax table has fortran-style comments as specified via the set_syntax_flags function.

### See also

define_syntax , set_syntax_flags

## function set_highlight_cache_dir

### Synopsis

set_highlight_cache_dir

### Usage

Void set_highlight_cache_dir (String dir);

### Description

This function sets the directory where the dfa syntax highlighting cache files are located. See also: enable_highlight_cache

## function set_syntax_flags

### Synopsis

set_syntax_flags

### Usage

Void set_syntax_flags (String table, Integer flag);

### Description

This function may be used to set the flags in the syntax table specified by the table parameter. The flag parameter may take any of the following values or any combination bitwise or-ed together:

          0x01     Keywords are case insensitive
          0x02     Comments are Fortran-like
          0x04     Ignore leading whitespace in C comments
          0x08     Keywords are TeX-like
          0x10     Comments start/end are whole words
          0x20     Syntax highlight whole preprocessor line in same color
          0x40     Leading whitespace allowed for preprocessor lines.

A Fortran-like comment means that any line that begins with certain specified characters is considered to be a comment. This special subset of characters must be specified via a call to the set_fortran_comment_chars function. If the 0x04 bit is set, then whitespace at the beginning of a line in a C comment preceeding a '*' character will not be highlighted. A TeX-like keyword is any word that follows the quote character.

### See also

define_syntax , set_fortran_comment_chars

## function use_syntax_table

### Synopsis

use_syntax_table

### Usage

Void use_syntax_table (String n);

### Description

This function associates the current buffer with the syntax table specified by the name n . Until another syntax table is associated with the buffer, the syntax table named n will be used in all operations that require a syntax. This includes parenthesis matching, indentation, etc.

### See also

create_syntax_table , define_syntax