handlebars.js/lib/handlebars/compiler/ast.js

import Exception from "../exception";

function LocationInfo(locInfo){
  locInfo = locInfo || {};
  this.firstLine   = locInfo.first_line;
  this.firstColumn = locInfo.first_column;
  this.lastColumn  = locInfo.last_column;
  this.lastLine    = locInfo.last_line;
}

var AST = {
  ProgramNode: function(statements, inverseStrip, inverse, locInfo) {
    var inverseLocationInfo, firstInverseNode;
    if (arguments.length === 3) {
      locInfo = inverse;
      inverse = null;
    } else if (arguments.length === 2) {
      locInfo = inverseStrip;
      inverseStrip = null;
    }

    LocationInfo.call(this, locInfo);
    this.type = "program";
    this.statements = statements;
    this.strip = {};

    if(inverse) {
      firstInverseNode = inverse[0];
      if (firstInverseNode) {
        inverseLocationInfo = {
          first_line: firstInverseNode.firstLine,
          last_line: firstInverseNode.lastLine,
          last_column: firstInverseNode.lastColumn,
          first_column: firstInverseNode.firstColumn
        };
        this.inverse = new AST.ProgramNode(inverse, inverseStrip, inverseLocationInfo);
      } else {
        this.inverse = new AST.ProgramNode(inverse, inverseStrip);
      }
      this.strip.right = inverseStrip.left;
    } else if (inverseStrip) {
      this.strip.left = inverseStrip.right;
    }
  },

  MustacheNode: function(rawParams, hash, open, strip, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "mustache";
    this.strip = strip;

    // Open may be a string parsed from the parser or a passed boolean flag
    if (open != null && open.charAt) {
      // Must use charAt to support IE pre-10
      var escapeFlag = open.charAt(3) || open.charAt(2);
      this.escaped = escapeFlag !== '{' && escapeFlag !== '&';
    } else {
      this.escaped = !!open;
    }

    if (rawParams instanceof AST.SexprNode) {
      this.sexpr = rawParams;
    } else {
      // Support old AST API
      this.sexpr = new AST.SexprNode(rawParams, hash);
    }

    // Support old AST API that stored this info in MustacheNode
    this.id = this.sexpr.id;
    this.params = this.sexpr.params;
    this.hash = this.sexpr.hash;
    this.eligibleHelper = this.sexpr.eligibleHelper;
    this.isHelper = this.sexpr.isHelper;
  },

  SexprNode: function(rawParams, hash) {
    this.type = "sexpr";
    this.hash = hash;

    var id = this.id = rawParams[0];
    var params = this.params = rawParams.slice(1);

    // a mustache is an eligible helper if:
    // * its id is simple (a single part, not `this` or `..`)
    var eligibleHelper = this.eligibleHelper = id.isSimple;

    // a mustache is definitely a helper if:
    // * it is an eligible helper, and
    // * it has at least one parameter or hash segment
    this.isHelper = eligibleHelper && (params.length || hash);

    // if a mustache is an eligible helper but not a definite
    // helper, it is ambiguous, and will be resolved in a later
    // pass or at runtime.
  },

  PartialNode: function(partialName, context, strip, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type         = "partial";
    this.partialName  = partialName;
    this.context      = context;
    this.strip = strip;
  },

  BlockNode: function(mustache, program, inverse, close, locInfo) {
    if(mustache.sexpr.id.original !== close.path.original) {
      throw new Exception(mustache.sexpr.id.original + " doesn't match " + close.path.original);
    }

    LocationInfo.call(this, locInfo);

    this.type = 'block';
    this.mustache = mustache;
    this.program  = program;
    this.inverse  = inverse;

    this.strip = {
      left: mustache.strip.left,
      right: close.strip.right
    };

    (program || inverse).strip.left = mustache.strip.right;
    (inverse || program).strip.right = close.strip.left;

    if (inverse && !program) {
      this.isInverse = true;
    }
  },

  ContentNode: function(string, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "content";
    this.string = string;
  },

  HashNode: function(pairs, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "hash";
    this.pairs = pairs;
  },

  IdNode: function(parts, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "ID";

    var original = "",
        dig = [],
        depth = 0;

    for(var i=0,l=parts.length; i<l; i++) {
      var part = parts[i].part;
      original += (parts[i].separator || '') + part;

      if (part === ".." || part === "." || part === "this") {
        if (dig.length > 0) { throw new Exception("Invalid path: " + original); }
        else if (part === "..") { depth++; }
        else { this.isScoped = true; }
      }
      else { dig.push(part); }
    }

    this.original = original;
    this.parts    = dig;
    this.string   = dig.join('.');
    this.depth    = depth;

    // an ID is simple if it only has one part, and that part is not
    // `..` or `this`.
    this.isSimple = parts.length === 1 && !this.isScoped && depth === 0;

    this.stringModeValue = this.string;
  },

  PartialNameNode: function(name, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "PARTIAL_NAME";
    this.name = name.original;
  },

  DataNode: function(id, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "DATA";
    this.id = id;
  },

  StringNode: function(string, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "STRING";
    this.original =
      this.string =
      this.stringModeValue = string;
  },

  IntegerNode: function(integer, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "INTEGER";
    this.original =
      this.integer = integer;
    this.stringModeValue = Number(integer);
  },

  BooleanNode: function(bool, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "BOOLEAN";
    this.bool = bool;
    this.stringModeValue = bool === "true";
  },

  CommentNode: function(comment, locInfo) {
    LocationInfo.call(this, locInfo);
    this.type = "comment";
    this.comment = comment;
  }
};

// Must be exported as an object rather than the root of the module as the jison lexer
// most modify the object to operate properly.
export default AST;