began work on parser, lexer

2013-12-23 15:05:58 +01:00
parent 4f0042bed1
commit 8f77a82170
8 changed files with 8273 additions and 0 deletions
@@ -0,0 +1,167 @@
+define([
+  './lexer'
+], function (Lexer) {
+
+  var NodeTypes = {
+    MetricExpression = 1,
+    MetricNode: 2,
+    FunctionCall: 4
+  };
+
+  function Node(type, value) {
+    this.type = type;
+    this.value = value;
+  }
+
+  function Parser(expression) {
+    this.expression = expression;
+    this.lexer = new Lexer(expression);
+    this.state = "start";
+    this.error = null;
+  }
+
+  Parser.prototype = {
+      getAst: function () {
+        return parse('start');
+      },
+
+      checkToken: function (token, expected) {
+        if (token === null) {
+          this.error = "Expected token: " + expected + " instead found end of string";
+          return;
+        }
+
+        if (token.type === expected) {
+          return true;
+        }
+
+        this.error = "Expected  token "
+            + expected + " instead found + "
+            found + " at position: " + lexer.char;
+
+        return false;
+      },
+
+      parse: function (state) {
+        var node = { children: [] };
+
+        var token = lexer.next();
+        var nextToken = lexer.next();
+
+        if (checkToken(token, Lexer.Token.Identifier) {
+          return null;
+        }
+
+        if (nextToken == null) {
+          return {
+            type: NodeTypes.MetricExpression,
+            nodes: [
+              {
+                type: NodeTypes.MetricNode,
+                value: token.value
+              }
+            ]
+          }
+        }
+
+        if (checkToken(nextToken, Lexer.Token.Punctuator)) {
+          return null;
+        }
+
+        if (nextToken.value === '.') {
+          return parseMetricExpression(token);
+        }
+      },
+
+      parseMetricExpression: function(firstToken) {
+        var node = {
+          type: NodeTypes.MetricExpression,
+          nodes: [
+            {
+              type: NodeTypes.MetricNode,
+              value: firstToken.value
+            }
+          ]
+        };
+
+        var token;
+
+        while(true) {
+          token = lexer.nextToken();
+          if (checkToken(token, Lexer.Token.Identifier)) {
+            return null;
+          }
+
+        }
+      }
+        /*while(true) {
+          token = lexer.next();
+
+          switch(state) {
+
+          case "start":
+            if (checkToken(token, Lexer.Token.Identifier) {
+              return;
+            }
+
+            state = "identifier";
+            prevToken = token;
+            break;
+
+          case "identifier":
+            if (token == null) {
+              node.type = NodeTypes.MetricExpression;
+              node.children.push([
+                type: NodeTypes.MetricNode,
+                value: prevToken.value;
+              ]);
+
+              return node;
+            }
+
+            if (checkToken(token, Lexer.Token.Punctuator)) {
+              return;
+            }
+
+            if (token.value === '.') {
+              state = "metricNode";
+              node.type = NodeTypes.MetricExpression;
+              node.children.push({
+                type: NodeTypes.MetricNode,
+                value: prevToken.value
+              });
+            }
+
+            if (token.value === '(') {
+              state = 'function';
+            }
+
+            break;
+          case 'metricEnd':
+            if (token === null) {
+              return node;
+            }
+
+            if (checkToken(token, Lexer.Token.Punctuator)) {
+              return null;
+            }
+
+          case 'metricNode':
+            if (checkToken(token, Lexer.Token.Identifier)) {
+              return null;
+            }
+
+            node.children.push([
+              type: NodeTypes.MetricNode,
+              value: token.value
+            ]);
+
+            state = 'metricEnd';
+            break;
+          }
+        }
+      }*/
+  };
+
+  return Parser;
+});