cm-church.js

/**
 * Author: Koh Zi Han, based on implementation by Koh Zi Chun
 */

var CodeMirror = require('codemirror');

CodeMirror.defineMode("scheme", function () {
    var BUILTIN = "builtin", COMMENT = "comment", STRING = "string",
        ATOM = "atom", NUMBER = "number", BRACKET = "bracket";
    var INDENT_WORD_SKIP = 2;

    function makeKeywords(str) {
        var obj = {}, words = str.split(" ");
        for (var i = 0; i < words.length; ++i) obj[words[i]] = true;
        return obj;
    }

    var keywords = makeKeywords("λ case-lambda call/cc class define-class exit-handler field import inherit init-field interface let*-values let-values let/ec mixin opt-lambda override protect provide public rename require require-for-syntax syntax syntax-case syntax-error unit/sig unless when with-syntax and begin call-with-current-continuation call-with-input-file call-with-output-file case cond define define-syntax delay do dynamic-wind else for-each if lambda let let* let-syntax letrec letrec-syntax map or syntax-rules abs acos angle append apply asin assoc assq assv atan boolean? caar cadr call-with-values car cdddar cddddr cdr ceiling char->integer char-alphabetic? char-ci<=? char-ci<? char-ci=? char-ci>=? char-ci>? char-downcase char-lower-case? char-numeric? char-ready? char-upcase char-upper-case? char-whitespace? char<=? char<? char=? char>=? char>? char? close-input-port close-output-port complex? cons cos current-input-port current-output-port denominator display eof-object? eq? equal? eqv? eval even? exact->inexact exact? exp expt #f floor force gcd imag-part inexact->exact inexact? input-port? integer->char integer? interaction-environment lcm length list list->string list->vector list-ref list-tail list? load log magnitude make-polar make-rectangular make-string make-vector max member memq memv min modulo negative? newline not null-environment null? number->string number? numerator odd? open-input-file open-output-file output-port? pair? peek-char port? positive? procedure? quasiquote quote quotient rational? rationalize read read-char real-part real? remainder reverse round scheme-report-environment set! set-car! set-cdr! sin sqrt string string->list string->number string->symbol string-append string-ci<=? string-ci<? string-ci=? string-ci>=? string-ci>? string-copy string-fill! string-length string-ref string-set! string<=? string<? string=? string>=? string>? string? substring symbol->string symbol? #t tan transcript-off transcript-on truncate values vector vector->list vector-fill! vector-length vector-ref vector-set! with-input-from-file with-output-to-file write write-char zero? barplot enumeration-query rejection-query mh-query condition factor fold flatten pair first second third fourth fifth sixth seventh rest flip hist repeat gaussian density multiviz uniform-draw mem sum runPhysics animatePhysics uniform worldWidth worldHeight scatter lineplot dirichlet multinomial beta mean");
    var indentKeys = makeKeywords("define let letrec let* lambda");

    function stateStack(indent, type, prev) { // represents a state stack object
        this.indent = indent;
        this.type = type;
        this.prev = prev;
    }

    function pushStack(state, indent, type) {
        state.indentStack = new stateStack(indent, type, state.indentStack);
    }

    function popStack(state) {
        state.indentStack = state.indentStack.prev;
    }

    var binaryMatcher = new RegExp(/^(?:[-+]i|[-+][01]+#*(?:\/[01]+#*)?i|[-+]?[01]+#*(?:\/[01]+#*)?@[-+]?[01]+#*(?:\/[01]+#*)?|[-+]?[01]+#*(?:\/[01]+#*)?[-+](?:[01]+#*(?:\/[01]+#*)?)?i|[-+]?[01]+#*(?:\/[01]+#*)?)(?=[()\s;"]|$)/i);
    var octalMatcher = new RegExp(/^(?:[-+]i|[-+][0-7]+#*(?:\/[0-7]+#*)?i|[-+]?[0-7]+#*(?:\/[0-7]+#*)?@[-+]?[0-7]+#*(?:\/[0-7]+#*)?|[-+]?[0-7]+#*(?:\/[0-7]+#*)?[-+](?:[0-7]+#*(?:\/[0-7]+#*)?)?i|[-+]?[0-7]+#*(?:\/[0-7]+#*)?)(?=[()\s;"]|$)/i);
    var hexMatcher = new RegExp(/^(?:[-+]i|[-+][\da-f]+#*(?:\/[\da-f]+#*)?i|[-+]?[\da-f]+#*(?:\/[\da-f]+#*)?@[-+]?[\da-f]+#*(?:\/[\da-f]+#*)?|[-+]?[\da-f]+#*(?:\/[\da-f]+#*)?[-+](?:[\da-f]+#*(?:\/[\da-f]+#*)?)?i|[-+]?[\da-f]+#*(?:\/[\da-f]+#*)?)(?=[()\s;"]|$)/i);
    var decimalMatcher = new RegExp(/^(?:[-+]i|[-+](?:(?:(?:\d+#+\.?#*|\d+\.\d*#*|\.\d+#*|\d+)(?:[esfdl][-+]?\d+)?)|\d+#*\/\d+#*)i|[-+]?(?:(?:(?:\d+#+\.?#*|\d+\.\d*#*|\.\d+#*|\d+)(?:[esfdl][-+]?\d+)?)|\d+#*\/\d+#*)@[-+]?(?:(?:(?:\d+#+\.?#*|\d+\.\d*#*|\.\d+#*|\d+)(?:[esfdl][-+]?\d+)?)|\d+#*\/\d+#*)|[-+]?(?:(?:(?:\d+#+\.?#*|\d+\.\d*#*|\.\d+#*|\d+)(?:[esfdl][-+]?\d+)?)|\d+#*\/\d+#*)[-+](?:(?:(?:\d+#+\.?#*|\d+\.\d*#*|\.\d+#*|\d+)(?:[esfdl][-+]?\d+)?)|\d+#*\/\d+#*)?i|(?:(?:(?:\d+#+\.?#*|\d+\.\d*#*|\.\d+#*|\d+)(?:[esfdl][-+]?\d+)?)|\d+#*\/\d+#*))(?=[()\s;"]|$)/i);

    function isBinaryNumber (stream) {
        return stream.match(binaryMatcher);
    }

    function isOctalNumber (stream) {
        return stream.match(octalMatcher);
    }

    function isDecimalNumber (stream, backup) {
        if (backup === true) {
            stream.backUp(1);
        }
        return stream.match(decimalMatcher);
    }

    function isHexNumber (stream) {
        return stream.match(hexMatcher);
    }

    return {
        startState: function () {
            return {
                indentStack: null,
                indentation: 0,
                mode: false,
                sExprComment: false
            };
        },

        token: function (stream, state) {
            if (state.indentStack == null && stream.sol()) {
                // update indentation, but only if indentStack is empty
                state.indentation = stream.indentation();
            }

            // skip spaces
            if (stream.eatSpace()) {
                return null;
            }
            var returnType = null;

            switch(state.mode){
            case "string": // multi-line string parsing mode
                var next, escaped = false;
                while ((next = stream.next()) != null) {
                    if (next == "\"" && !escaped) {

                        state.mode = false;
                        break;
                    }
                    escaped = !escaped && next == "\\";
                }
                returnType = STRING; // continue on in scheme-string mode
                break;
            case "comment": // comment parsing mode
                var next, maybeEnd = false;
                while ((next = stream.next()) != null) {
                    if (next == "#" && maybeEnd) {

                        state.mode = false;
                        break;
                    }
                    maybeEnd = (next == "|");
                }
                returnType = COMMENT;
                break;
            case "s-expr-comment": // s-expr commenting mode
                state.mode = false;
                if(stream.peek() == "(" || stream.peek() == "["){
                    // actually start scheme s-expr commenting mode
                    state.sExprComment = 0;
                }else{
                    // if not we just comment the entire of the next token
                    stream.eatWhile(/[^/s]/); // eat non spaces
                    returnType = COMMENT;
                    break;
                }
            default: // default parsing mode
                var ch = stream.next();

                if (ch == "\"") {
                    state.mode = "string";
                    returnType = STRING;

                } else if (ch == "'") {
                    returnType = ATOM;
                } else if (ch == '#') {
                    if (stream.eat("|")) {                    // Multi-line comment
                        state.mode = "comment"; // toggle to comment mode
                        returnType = COMMENT;
                    } else if (stream.eat(/[tf]/i)) {            // #t/#f (atom)
                        returnType = ATOM;
                    } else if (stream.eat(';')) {                // S-Expr comment
                        state.mode = "s-expr-comment";
                        returnType = COMMENT;
                    } else {
                        var numTest = null, hasExactness = false, hasRadix = true;
                        if (stream.eat(/[ei]/i)) {
                            hasExactness = true;
                        } else {
                            stream.backUp(1);       // must be radix specifier
                        }
                        if (stream.match(/^#b/i)) {
                            numTest = isBinaryNumber;
                        } else if (stream.match(/^#o/i)) {
                            numTest = isOctalNumber;
                        } else if (stream.match(/^#x/i)) {
                            numTest = isHexNumber;
                        } else if (stream.match(/^#d/i)) {
                            numTest = isDecimalNumber;
                        } else if (stream.match(/^[-+0-9.]/, false)) {
                            hasRadix = false;
                            numTest = isDecimalNumber;
                            // re-consume the intial # if all matches failed
                        } else if (!hasExactness) {
                            stream.eat('#');
                        }
                        if (numTest != null) {
                            if (hasRadix && !hasExactness) {
                                // consume optional exactness after radix
                                stream.match(/^#[ei]/i);
                            }
                            if (numTest(stream))
                                returnType = NUMBER;
                        }
                    }
                } else if (/^[-+0-9.]/.test(ch) && isDecimalNumber(stream, true)) { // match non-prefixed number, must be decimal
                    returnType = NUMBER;
                } else if (ch == ";") { // comment
                    stream.skipToEnd(); // rest of the line is a comment
                    returnType = COMMENT;
                } else if (ch == "(" || ch == "[") {
                    var keyWord = ''; var indentTemp = stream.column(), letter;
                    /**
                       Either
                       (indent-word ..
                       (non-indent-word ..
                       (;something else, bracket, etc.
                    */

                    while ((letter = stream.eat(/[^\s\(\[\;\)\]]/)) != null) {
                        keyWord += letter;
                    }

                    if (keyWord.length > 0 && indentKeys.propertyIsEnumerable(keyWord)) { // indent-word

                        pushStack(state, indentTemp + INDENT_WORD_SKIP, ch);
                    } else { // non-indent word
                        // we continue eating the spaces
                        stream.eatSpace();
                        if (stream.eol() || stream.peek() == ";") {
                            // nothing significant after
                            // we restart indentation 1 space after
                            pushStack(state, indentTemp + 1, ch);
                        } else {
                            pushStack(state, indentTemp + stream.current().length, ch); // else we match
                        }
                    }
                    stream.backUp(stream.current().length - 1); // undo all the eating

                    if(typeof state.sExprComment == "number") state.sExprComment++;

                    returnType = BRACKET;
                } else if (ch == ")" || ch == "]") {
                    returnType = BRACKET;
                    if (state.indentStack != null && state.indentStack.type == (ch == ")" ? "(" : "[")) {
                        popStack(state);

                        if(typeof state.sExprComment == "number"){
                            if(--state.sExprComment == 0){
                                returnType = COMMENT; // final closing bracket
                                state.sExprComment = false; // turn off s-expr commenting mode
                            }
                        }
                    }
                } else {
                    stream.eatWhile(/[\w\$_\-!$%&*+\.\/:<=>?@\^~]/);

                    if (keywords && keywords.propertyIsEnumerable(stream.current())) {
                        returnType = BUILTIN;
                    } else returnType = "variable";
                }
            }
            return (typeof state.sExprComment == "number") ? COMMENT : returnType;
        },

        indent: function (state) {
            if (state.indentStack == null) return state.indentation;
            return state.indentStack.indent;
        },

        lineComment: ";;"
    };
});

CodeMirror.defineMIME("text/x-scheme", "scheme");