From 7bda9de511a5642efb297eae98c6ea7c42b27754 Mon Sep 17 00:00:00 2001
From: "Benjamin J. Culkin" <bjculkin@mix.wvu.edu>
Date: Wed, 25 Oct 2017 12:10:14 -0300
Subject: Start switch to maven modules

---
 base/src/bjc/dicelang/expr/Lexer.java | 62 +++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 base/src/bjc/dicelang/expr/Lexer.java

(limited to 'base/src/bjc/dicelang/expr/Lexer.java')

diff --git a/base/src/bjc/dicelang/expr/Lexer.java b/base/src/bjc/dicelang/expr/Lexer.java
new file mode 100644
index 0000000..dfa0f76
--- /dev/null
+++ b/base/src/bjc/dicelang/expr/Lexer.java
@@ -0,0 +1,62 @@
+package bjc.dicelang.expr;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import bjc.utils.funcdata.IList;
+import bjc.utils.parserutils.splitter.ConfigurableTokenSplitter;
+
+/*
+ * @TODO 10/08/18 :IntExpressions
+ * 	Add support for integer constants, and maybe floating-point ones as well
+ * 	if you feel like. Heck, you could even go for ratio constants and things
+ * 	as well.
+ */
+/**
+ * Implements the lexer for simple expression operations.
+ *
+ * @author Ben Culkin
+ */
+public class Lexer {
+	/* Splitter we use. */
+	private final ConfigurableTokenSplitter split;
+
+	/** Create a new expression lexer. */
+	public Lexer() {
+		split = new ConfigurableTokenSplitter(true);
+
+		split.addSimpleDelimiters("(", ")");
+		split.addSimpleDelimiters("+", "-", "*", "/");
+	}
+
+	/**
+	 * Convert a string from a input command to a series of infix tokens.
+	 *
+	 * @param inp
+	 *                The input command.
+	 *
+	 * @param tks
+	 *                The token state.
+	 *
+	 * @return A series of infix tokens representing the command.
+	 */
+	public Token[] lexString(final String inp, final Tokens tks) {
+		/* Split tokens on whitespace. */
+		final String[] spacedTokens = inp.split("[ \t]");
+		/* Tokens to return. */
+		final List<Token> tokens    = new LinkedList<>();
+
+		/* Process each token. */
+		for (final String spacedToken : spacedTokens) {
+			/* Split on operators. */
+			final IList<String> splitTokens = split.split(spacedToken);
+			/* Convert strings to tokens. */
+			final IList<Token> rawTokens    = splitTokens.map(tok -> tks.lexToken(tok, spacedToken));
+
+			/* Add tokens to results. */
+			rawTokens.forEach(tokens::add);
+		}
+
+		return tokens.toArray(new Token[0]);
+	}
+}
-- 
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