From 1c751353f1aeefd9cd3005d6093f826765982ce2 Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Fri, 18 Aug 2017 14:21:14 -0700
Subject: [PATCH] Lex and parse variables.

---
 .../main/java/org/nwapw/abacus/parsing/LexerTokenizer.java    | 1 +
 .../java/org/nwapw/abacus/parsing/ShuntingYardParser.java     | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/core/src/main/java/org/nwapw/abacus/parsing/LexerTokenizer.java b/core/src/main/java/org/nwapw/abacus/parsing/LexerTokenizer.java
index 790882a..b7bdd1f 100644
--- a/core/src/main/java/org/nwapw/abacus/parsing/LexerTokenizer.java
+++ b/core/src/main/java/org/nwapw/abacus/parsing/LexerTokenizer.java
@@ -34,6 +34,7 @@ public class LexerTokenizer implements Tokenizer<Match<TokenType>>, PluginListen
             register(" ", TokenType.WHITESPACE);
             register(",", TokenType.COMMA);
             register("[0-9]*(\\.[0-9]+)?", TokenType.NUM);
+            register("[a-zA-Z]+", TokenType.VARIABLE);
             register("\\(", TokenType.OPEN_PARENTH);
             register("\\)", TokenType.CLOSE_PARENTH);
         }};
diff --git a/core/src/main/java/org/nwapw/abacus/parsing/ShuntingYardParser.java b/core/src/main/java/org/nwapw/abacus/parsing/ShuntingYardParser.java
index c7a5615..af9936b 100644
--- a/core/src/main/java/org/nwapw/abacus/parsing/ShuntingYardParser.java
+++ b/core/src/main/java/org/nwapw/abacus/parsing/ShuntingYardParser.java
@@ -61,7 +61,7 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
             Match<TokenType> match = from.remove(0);
             previousType = matchType;
             matchType = match.getType();
-            if (matchType == TokenType.NUM) {
+            if (matchType == TokenType.NUM || matchType == TokenType.VARIABLE) {
                 output.add(match);
             } else if (matchType == TokenType.FUNCTION) {
                 output.add(new Match<>("", TokenType.INTERNAL_FUNCTION_END));
@@ -144,6 +144,8 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
             }
         } else if (matchType == TokenType.NUM) {
             return new NumberNode(abacus.numberFromString(match.getContent()));
+        } else if (matchType == TokenType.VARIABLE) {
+            return new VariableNode(match.getContent());
         } else if (matchType == TokenType.FUNCTION) {
             String functionName = match.getContent();
             FunctionNode node = new FunctionNode(functionName);