1 files changed, 290 insertions, 0 deletions
diff --git a/src/main/java/bjc/rgens/parser/RGrammarSet.java b/src/main/java/bjc/rgens/parser/RGrammarSet.java
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+++ b/src/main/java/bjc/rgens/parser/RGrammarSet.java
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+package bjc.rgens.parser;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.Set;
+
+/**
+ * Represents a set of grammars that can share rules via exports.
+ *
+ * @author EVE
+ */
+public class RGrammarSet {
+	/* Contains all the grammars in this set. */
+	private Map<String, RGrammar> grammars;
+
+	/* Contains all the exported rules from grammars. */
+	private Map<String, RGrammar> exportedRules;
+
+	/* Contains which export came from which grammar. */
+	private Map<String, String> exportFrom;
+
+	/* Contains which file a grammar was loaded from. */
+	private Map<String, String> loadedFrom;
+
+	/** Create a new set of randomized grammars. */
+	public RGrammarSet() {
+		grammars = new HashMap<>();
+
+		exportedRules = new HashMap<>();
+
+		exportFrom = new HashMap<>();
+		loadedFrom = new HashMap<>();
+	}
+
+	/**
+	 * Add a grammar to this grammar set.
+	 *
+	 * @param grammarName
+	 * 	The name of the grammar to add.
+	 *
+	 * @param gram
+	 * 	The grammar to add.
+	 *
+	 * @throws IllegalArgumentException
+	 * 	If the grammar name is invalid.
+	 */
+	public void addGrammar(String grammarName, RGrammar gram) {
+		/* Make sure a grammar is valid. */
+		if (grammarName == null) {
+			throw new NullPointerException("Grammar name must not be null");
+		} else if (gram == null) {
+			throw new NullPointerException("Grammar must not be null");
+		} else if (grammarName.equals("")) {
+			throw new IllegalArgumentException("The empty string is not a valid grammar name");
+		}
+
+		grammars.put(grammarName, gram);
+
+		/* Process exports from the grammar. */
+		for (Rule export : gram.getExportedRules()) {
+			exportedRules.put(export.name, gram);
+
+			exportFrom.put(export.name, grammarName);
+		}
+
+		/* Add exports to grammar. */
+		gram.setImportedRules(exportedRules);
+	}
+
+	/**
+	 * Get a grammar from this grammar set.
+	 *
+	 * @param grammarName
+	 * 	The name of the grammar to get.
+	 *
+	 * @return
+	 * 	The grammar with that name.
+	 *
+	 * @throws IllegalArgumentException
+	 * 	If the grammar name is invalid or not present in this set.
+	 */
+	public RGrammar getGrammar(String grammarName) {
+		/* Check arguments. */
+		if (grammarName == null) {
+			throw new NullPointerException("Grammar name must not be null");
+		} else if (grammarName.equals("")) {
+			throw new IllegalArgumentException("The empty string is not a valid grammar name");
+		} else if (!grammars.containsKey(grammarName)) {
+			String msg = String.format("No grammar with name '%s' found", grammarName);
+
+			throw new IllegalArgumentException(msg);
+		}
+
+		return grammars.get(grammarName);
+	}
+
+	/**
+	 * Get the grammar a rule was exported from.
+	 *
+	 * @param exportName
+	 * 	The name of the exported rule.
+	 *
+	 * @return
+	 * 	The grammar the exported rule came from.
+	 *
+	 * @throws IllegalArgumentException
+	 * 	If the export name is invalid or not present in this set.
+	 */
+	public RGrammar getExportSource(String exportName) {
+		/* Check arguments. */
+		if (exportName == null) {
+			throw new NullPointerException("Export name must not be null");
+		} else if (exportName.equals("")) {
+			throw new IllegalArgumentException("The empty string is not a valid rule name");
+		} else if (!exportedRules.containsKey(exportName)) {
+			String msg = String.format("No export with name '%s' defined", exportName);
+			throw new IllegalArgumentException(msg);
+		}
+
+		return exportedRules.get(exportName);
+	}
+
+	/**
+	 * Get the source of an exported rule.
+	 *
+	 * This will often be a grammar name, but is not required to be one.
+	 *
+	 * @param exportName
+	 * 	The name of the exported rule.
+	 *
+	 * @return 
+	 * 	The source of an exported rule.
+	 *
+	 * @throws IllegalArgumentException
+	 * 	If the exported rule is invalid or not present in this set.
+	 */
+	public String exportedFrom(String exportName) {
+		/* Check arguments. */
+		if (exportName == null) {
+			throw new NullPointerException("Export name must not be null");
+		} else if (exportName.equals("")) {
+			throw new IllegalArgumentException("The empty string is not a valid rule name");
+		} else if (!exportedRules.containsKey(exportName)) {
+			String msg = String.format("No export with name '%s' defined", exportName);
+
+			throw new IllegalArgumentException(msg);
+		}
+
+		return exportFrom.getOrDefault(exportName, "Unknown");
+	}
+
+	/**
+	 * Get the source of an grammar
+	 *
+	 * This will often be a file name, but is not required to be one.
+	 *
+	 * @param grammarName
+	 * 	The name of the exported grammar.
+	 *
+	 * @return
+	 * 	The source of an exported grammar.
+	 *
+	 * @throws IllegalArgumentException
+	 * 	If the exported grammar is invalid or not present in this set.
+	 */
+	public String loadedFrom(String grammarName) {
+		/* Check arguments. */
+		if (grammarName == null) {
+			throw new NullPointerException("Grammar name must not be null");
+		} else if (grammarName.equals("")) {
+			throw new IllegalArgumentException("The empty string is not a valid grammar name");
+		} else if (grammarName.equals("unknown")) {
+			return grammarName;
+		} else if (!grammars.containsKey(grammarName)) {
+			String msg = String.format("No grammar with name '%s' defined", grammarName);
+			throw new IllegalArgumentException(msg);
+		}
+
+		return loadedFrom.getOrDefault(grammarName, "Unknown");
+	}
+
+	/**
+	 * Get the names of all the grammars in this set.
+	 *
+	 * @return
+	 * 	The names of all the grammars in this set.
+	 */
+	public Set<String> getGrammars() {
+		return grammars.keySet();
+	}
+
+	/**
+	 * Get the names of all the exported rules in this set.
+	 *
+	 * @return
+	 * 	The names of all the exported rules in this set.
+	 */
+	public Set<String> getExportedRules() {
+		return exportedRules.keySet();
+	}
+
+	/**
+	 * Load a grammar set from a configuration file.
+	 *
+	 * @param cfgFile
+	 * 	The configuration file to load from.
+	 *
+	 * @return
+	 * 	The grammar set created by the configuration file.
+	 *
+	 * @throws IOException
+	 * 	If something goes wrong during configuration loading.
+	 */
+	public static RGrammarSet fromConfigFile(Path cfgFile) throws IOException {
+		/* The grammar set to hand back. */
+		RGrammarSet set = new RGrammarSet();
+
+		/* Get the directory that contains the config file. */
+		Path cfgParent = cfgFile.getParent();
+
+		try(Scanner scn = new Scanner(cfgFile)) {
+			/* Execute lines from the configuration file. */
+			while (scn.hasNextLine()) {
+				String ln = scn.nextLine().trim();
+
+				/* Ignore blank/comment lines. */
+				if (ln.equals("")) continue;
+
+				if (ln.startsWith("#")) continue;
+
+				/* Handle mixed whitespace. */
+				ln = ln.replaceAll("\\s+", " ");
+
+				/* 
+				 * Get the place where the name of the grammar
+				 * ends. 
+				 */
+				int nameIdx = ln.indexOf(" ");
+				if (nameIdx == -1) {
+					throw new GrammarException("Must specify a name for a loaded grammar");
+				}
+
+				/* Name and path of grammar. */
+				String name = ln.substring(0, nameIdx);
+				Path path   = Paths.get(ln.substring(nameIdx).trim());
+
+				/*
+				 * Convert from configuration relative path to
+				 * absolute path.
+				 */
+				Path convPath = cfgParent.resolve(path.toString());
+
+				//if(Files.isDirectory(convPath)) {
+				//	/* @TODO implement subset grammars */
+				//	throw new GrammarException("Sub-grammar sets aren't implemented yet");
+				//} else if (convPath.getFileName().endsWith(".gram")) {
+					/* Load grammar file. */
+					try {
+						BufferedReader fis = Files.newBufferedReader(convPath);
+						RGrammar gram = RGrammarParser.readGrammar(fis);
+						fis.close();
+
+						/* Add grammar to the set. */
+						set.addGrammar(name, gram);
+
+						/*
+						 * Mark where the grammar came
+						 * from. 
+						 */
+						set.loadedFrom.put(name, path.toString());
+					} catch (GrammarException gex) {
+						String msg = String.format("Error loading file '%s'", path);
+						throw new GrammarException(msg, gex);
+					}
+				//} else {
+				//	String msg = String.format("Unrecognized file type '%s'", convPath.getFileName());
+				//	throw new GrammarException(msg);
+				//}
+			}
+		}
+
+		return set;
+	}
+}