BBCBASIC.sublime-syntax

%YAML 1.2
---
# BBC BASIC syntax colouring mode.
#
# Intended for use with BBC BASIC V/VI files in text format, for RISC OS. Should work
# acceptably well with earlier versions of BBC BASIC and variants from other platforms.
#

# See http://www.sublimetext.com/docs/3/syntax.html
name: BBC BASIC
file_extensions: ['bbc']
scope: source.bbcbasic

contexts:
  main:
    # The main context is the initial starting point of our syntax.
    # Include other contexts from here (or specify them directly).
    - include: linenumber
    - include: comments
    - include: keywords
    - include: cli
    - include: numbers
    - include: variables
    - include: strings

  linenumber:
    - match: "^ *[0-9]+ *"
      scope: entity.line-number.bbcbasic

  keywords:
    - match: "(DEF *(?:PROC|FN)) *([@`A-Za-z_][@`A-Za-z_0-9]*)"
      captures:
        '1': storage.type.function.bbcbasic
        '2': entity.name.function.bbcbasic

    - match: "(END *PROC)$"
      scope: storage.type.function.bbcbasic

    - match: "^="
      # Try to identify the '=' termination of the function
      scope: storage.type.function.bbcbasic

    # Conditional statements
    - match: "(IF|THEN|ELSE|ENDIF)"
      scope: keyword.control.flow.bbcbasic

    # Switch statements
    - match: "(CASE|OTHERWISE|WHEN|ENDCASE)"
      scope: keyword.control.flow.bbcbasic

    # Loop statements
    - match: "(FOR|NEXT|REPEAT|UNTIL|WHILE|ENDWHILE)"
      scope: keyword.control.flow.bbcbasic

    # Legacy control flow
    - match: "(RETURN|GOTO|GOSUB)"
      scope: keyword.control.flow.bbcbasic

    # Exceptional operations
    - match: "(ON|END|STOP|QUIT)"
      scope: keyword.control.flow.bbcbasic

    - match: "(PROC|FN)([`@A-Za-z_][`@A-Za-z_0-9]*)"
      captures:
        '1': keyword.control.bbcbasic
        '2': meta.function-call.bbcbasic

    - match: "\
        CHR\\$|GET\\$|INKEY\\$|LEFT\\$|MID\\$|RIGHT\\$|STR\\$|STRING\\$|TIME\\$|REPORT\\$|\
        ERROR|\
        LINE|OFF|STEP|SPC|TAB|\
        OPENIN|PAGE|TIME|LOMEM|HIMEM|ABS|\
        ACS|ADVAL|ASC|ASN|ATN|BGET#|COS|COUNT|\
        DEG|ERL|ERR|EVAL|EXP|EXT#|FALSE|\
        GET|INKEY|INSTR|INT|LEN|LN|LOG|NOT|\
        OPENUP|OPENOUT|PI|POINT|POS|RAD|RND|\
        SGN|SIN|SQR|TAN|TO|TRUE|USR|VAL|VPOS|\
        EOF#|PTR#|PAGE|TIME|\
        SOUND|BPUT#|CALL|CHAIN|CLEAR|\
        CLOSE#|CLG|CLS|DATA|DIM|DRAW|\
        ENVELOPE|GCOL|\
        INPUT|LET|LOCAL|MODE|MOVE|\
        VDU|PLOT|PRINT|PROC|READ|\
        REPORT|RESTORE|RUN|COLOUR|\
        TRACE|WIDTH|OSCLI|\
        OF|\
        CIRCLE|FILL|ORIGIN|POINT|RECTANGLE|SWAP|\
        WAIT|MOUSE|SYS|INSTALL|\
        LIBRARY|TINT|ELLIPSE|BEATS|TEMPO|VOICES|\
        VOICE|STEREO|OVERLAY|APPEND|AUTO|CRUNCH|\
        DELETE|EDIT|HELP|LIST|LOAD|LVAR|NEW|\
        OLD|RENUMBER|SAVE|TEXTLOAD|TEXTSAVE|\
        TWINO|TWIN|INSTALL|SUM|BEAT|\
        AND|DIV|EOR|MOD|OR"
      scope: keyword.control.bbcbasic

  numbers:
    - match: '[+-]?[0-9]+(\.[0-9]+)?(E[\-+]?[0-9]+)'
      scope: constant.numeric.bbcbasic

    - match: '(-)?[0-9.]+|(&[0-9a-fA-F]{1,8})|%([01]+)'
      scope: constant.numeric.bbcbasic

  variables:
    - match: '[`A-Za-z_][`A-Za-z0-9_]*%'
      scope: variable.integer.bbcbasic

    - match: '[`A-Za-z_][`A-Za-z0-9_]*\$'
      scope: variable.string.bbcbasic

    - match: '[`A-Za-z_][`A-Za-z0-9_]*'
      scope: variable.float.bbcbasic

  strings:
    # Strings begin and end with quotes.
    - match: '(".*?")'
      scope: string.quoted.double.bbcbasic

  comments:
    # Comments begin with a 'REM' and finish at the end of the line.
    - match: 'REM'
      scope: punctuation.definition.comment.bbcbasic
      push:
        # This is an anonymous context push for brevity.
        - meta_scope: comment.line.rem.bbcbasic
        - match: $\n?
          pop: true

    # CLI commands that start with a | are effectively a comment
    # (Note: This does not cope with comments following a line number prefix)
    - match: '^ *\*\|.*'
      scope: comment.line.rem.bbcbasic

  cli:
    # CLI commands are harder to recognise without a stateful process here, but we try
    # to recognise what we can with the 'preprocessor' type of statement
    - match: '^( *|.*: *|.*THEN *|.*ELSE *)\*.*'
      scope: meta.directive.bbcbasic keyword.other.preprocessor.include.c