Syntax highlighting using Mediawiki formatting: Difference between revisions

=={{header|ALGOL W}}==

'''begin''' ''comment syntax highlight an Algol W source using Mediawiki formatting''

'' the source is read from standard input and written to standard output''

'' ;''

''% Algol W strings are limited to 256 characters in length so source lines %''

''% are limited to 256 characters %''

'''integer''' lineWidth, errorCount, lowerA, upperA, linePos, kwMax;

'''integer''' MAX_TOKEN_LENGTH;

'''string'''(1) nl;

'''string'''(256) line;

'''string'''(1) currChar, commentEnd;

'''string'''(9) '''array''' kw ( 1 :: 64 );

'''logical''' inString, inComment;

''% returns true if currChar is in the inclusive range low to high, false otherwise %''

'''logical''' '''procedure''' range( '''string'''(1) '''value''' low, high ) ; currChar >= low '''and''' currChar <= high;

'''procedure''' nextChar ; ''% gets the next source character %''

'''if''' linePos = lineWidth '''then''' '''begin'''

currChar := nl;

linePos := linePos + 1

'''end'''

'''else''' '''if''' linePos > lineWidth '''then''' '''begin'''

readcard( line );

lineWidth := 256;

'''while''' lineWidth > 1 '''and''' line( lineWidth - 1 // 1 ) = " " '''do''' lineWidth := lineWidth - 1;

linePos := 1;

currChar := line( 0 // 1 )

'''end'''

'''else''' '''begin'''

currChar := line( linePos // 1 );

linePos := linePos + 1

'''end''' nextChar ;

''% returns true if the current character can start an identifier, false otherwise %''

'''logical''' '''procedure''' identifierStartChar ; range( "a", "z" ) '''or''' range( "A", "Z" );

''% returns true if the current character can be pat of an identifier, false otherwise %''

'''logical''' '''procedure''' identifierChar ; identifierStartChar '''or''' range( "0", "9" ) '''or''' currChar = "_";

'''procedure''' outAndNextChar ; '''begin''' ''% output currChar and get the next %''

'''if''' currChar = "'" '''then''' writeon( "'" )

'''else''' '''if''' currChar = "&" '''then''' writeon( "&" )

'''else''' '''if''' currChar = "<" '''then''' writeon( "<" )

'''else''' '''if''' currChar = ">" '''then''' writeon( ">" )

'''else''' '''if''' currChar = nl '''then''' '''begin'''

'''if''' inComment '''then''' writeon( "''" );

write( " " );

'''if''' inComment '''then''' writeon( "''" )

'''end'''

'''else''' writeon( currChar );

nextChar

'''end''' outAndNextChar ;

'''procedure''' identifierOrKeyword ; '''begin''' ''% handle an indentifier or keyword %''

'''string'''(9) word, lWord;

'''integer''' wLength;

''% recursive keyword binary search %''

'''logical''' '''procedure''' isKeyword ( '''integer''' '''value''' low, high ) ;

'''if''' high < low '''then''' '''false'''

'''else''' '''begin'''

'''integer''' mid;

mid := ( low + high ) '''div''' 2;

'''if''' kw( mid ) > lWord '''then''' isKeyword( low, mid - 1 )

'''else''' '''if''' kw( mid ) = lWord '''then''' '''true'''

'''else''' isKeyword( mid + 1, high )

'''end''' binarySearchR ;

wLength := 0;

'''for''' chPos := 0 '''until''' 8 '''do''' '''begin'''

'''if''' identifierChar '''then''' '''begin'''

word( chPos // 1 ) := currChar;

lWord( chPos // 1 ) := '''if''' range( "A", "Z" ) '''then''' code( ( decode( currChar ) - upperA ) + lowerA )

'''else''' currChar;;

wLength := wLength + 1;

nextChar

'''end'''

'''else''' '''begin'''

lWord( chPos // 1 ) := " ";

word( chPos // 1 ) := " "

'''end''' if_identifierChar__

'''end''' for_chPos ;

'''if''' identifierChar '''then''' '''begin'''

''% all keywords are <= 9 characters long so this must be an identifier %''

writeon( word );

'''while''' identifierChar '''do''' outAndNextChar

'''end'''

'''else''' '''if''' lWord = "comment" '''then''' '''begin'''

writeon( "''comment" );

commentEnd := ";";

inComment := '''true'''

'''end'''

'''else''' '''if''' isKeyword( 1, kwMax ) '''then''' '''begin'''

writeon( "'''" );

'''for''' chPos := 0 '''until''' wLength - 1 '''do''' writeon( word( chPos // 1 ) );

writeon( "'''" )

'''end'''

'''else''' '''begin''' ''% identifier %''

'''for''' chPos := 0 '''until''' wLength - 1 '''do''' writeon( word( chPos // 1 ) )

'''end''' if_various_words

'''end''' identifierOrKeyword ;

s_w := 0; i_w := 1; ''% output formarting %''

MAX_TOKEN_LENGTH := 256;

nl := code( 10 );

lowerA := decode( "a" );

upperA := decode( "A" );

''% allow the program to continue after reaching end-of-file %''

ENDFILE := EXCEPTION( '''false''', 1, 0, '''false''', "EOF" );

''% ensure the first call to nextChar reads the first line %''

lineWidth := 256;

linePos := lineWidth + 1;

currChar := " ";

'''begin''' ''% keywords %''

'''procedure''' K ( '''string'''(9) '''value''' kwStr ) ; '''begin'''

kwMax := kwMax + 1;

kw( kwMax ) := kwStr

'''end''' K ;

kwMax := 0;

K("abs");K("algol");K("and");K("array");K("assert");K("begin");K("bits");

K("case");K("complex");K("div");K("do");K("else");K("end");K("false");

K("for");K("fortran");K("go");K("goto");K("if");K("integer");K("is");

K("logical");K("long");K("not");K("null");K("of");K("or");

K("procedure");K("real");K("record");K("reference");K("rem");K("result");

K("shl");K("short");K("shr");K("step");K("string");

K("then");K("to");K("true");K("until");K("value");K("while")

'''end''' keywords ;

inString := inComment := '''false''';

outAndNextChar;

'''while''' '''not''' XCPNOTED(ENDFILE) '''do''' '''begin'''

'''if''' inString '''then''' '''begin''' ''% in a string %''

inString := currChar '''not''' = """";

outAndNextChar;

'''end'''

'''else''' '''if''' inComment '''then''' '''begin''' ''% in a comment %''

inComment := currChar '''not''' = ";" '''and''' currChar '''not''' = commentEnd;

outAndNextChar;

'''if''' '''not''' inComment '''then''' writeon( "''" );

'''end'''

'''else''' '''if''' identifierStartChar '''then''' identifierOrKeyword

'''else''' '''if''' currChar = """" '''then''' '''begin''' ''% string literal %''

outAndNextChar;

inString := '''true'''

'''end'''

'''else''' '''if''' currChar = "%" '''then''' '''begin''' ''% brief comment %''

writeon( "''" );

commentEnd := "%";

inComment := '''true''';

outAndNextChar

'''end'''

'''else''' outAndNextChar

'''end''' while_not_ar_eof ;

'''if''' inComment '''then''' write( "**** unterminated comment" )

'''else''' '''if''' inString '''then''' write( "**** unterminated string" )

'''end'''.