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Diffstat (limited to 'src/main/java/bjc/rgens/parser/elements/CaseElement.java')
| -rwxr-xr-x | src/main/java/bjc/rgens/parser/elements/CaseElement.java | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/src/main/java/bjc/rgens/parser/elements/CaseElement.java b/src/main/java/bjc/rgens/parser/elements/CaseElement.java new file mode 100755 index 0000000..d74ab52 --- /dev/null +++ b/src/main/java/bjc/rgens/parser/elements/CaseElement.java @@ -0,0 +1,147 @@ +package bjc.rgens.parser.elements; + +import bjc.rgens.parser.GrammarException; + +/* + * @TODO 10/11/17 Ben Culkin :CaseElementSplit Split this into multiple + * subclasses based off of a value of ElementType. + */ +/** + * A element in a rule case. + * + * @author EVE + */ +public class CaseElement { + /** + * The possible types of an element. + * + * @author EVE + */ + public static enum ElementType { + /** An element that represents a literal string. */ + LITERAL, + /** An element that represents a rule reference. */ + RULEREF, + /** An element that represents a random range. */ + RANGE, + /** An element that represents a variable that stores a string. */ + VARDEF, + /** + * An element that represents a variable that stores the result of generating a + * rule. + */ + EXPVARDEF; + } + + /* Regexps for marking rule types. */ + private static final String SPECIAL_CASELEM = "\\{[^}]+\\}"; + private static final String REFER_CASELEM = "\\[[^\\]]+\\]"; + private static final String RANGE_CASELM = "\\[\\d+\\.\\.\\d+\\]"; + + /** The type of this element. */ + public final ElementType type; + + /** + * Create a new case element. + * + * @param typ + * The type of this element. + */ + protected CaseElement(ElementType typ) { + type = typ; + } + + @Override + public String toString() { + switch (type) { + default: + return String.format("Unknown type '%s'", type); + } + } + + /** + * Create a case element from a string. + * + * @param csepart + * The string to convert. + * + * @return A case element representing the string. + */ + public static CaseElement createElement(String csepart) { + if (csepart == null) { + throw new NullPointerException("Case part cannot be null"); + } + + if (csepart.matches(SPECIAL_CASELEM)) { + /* Handle special cases. */ + String specialBody = csepart.substring(1, csepart.length() - 1); + + System.out.printf("\t\tTRACE: special body is '%s'\n", specialBody); + + if (specialBody.matches("\\S+:=\\S+")) { + /* Handle expanding variable definitions. */ + String[] parts = specialBody.split(":="); + + if (parts.length != 2) { + String msg = "Expanded variables must be a name and a definition, seperated by :="; + + throw new GrammarException(msg); + } + + return new ExpVariableCaseElement(parts[0], parts[1]); + } else if (specialBody.matches("\\S+=\\S+")) { + /* Handle regular variable definitions. */ + String[] parts = specialBody.split("="); + + if (parts.length != 2) { + String msg = "Variables must be a name and a definition, seperated by ="; + + throw new GrammarException(msg); + } + + return new LitVariableCaseElement(parts[0], parts[1]); + } else if (specialBody.matches("{empty}")) { + /* Literal blank, for empty cases. */ + return new BlankCaseElement(); + } else { + throw new IllegalArgumentException(String.format("Unknown special case part '%s'", specialBody)); + } + } else if (csepart.matches(REFER_CASELEM)) { + if (csepart.matches(RANGE_CASELM)) { + /* Handle ranges */ + String rawRange = csepart.substring(1, csepart.length() - 1); + + int firstNum = Integer.parseInt(rawRange.substring(0, rawRange.indexOf('.'))); + int secondNum = Integer.parseInt(rawRange.substring(rawRange.lastIndexOf('.') + 1)); + + return new RangeCaseElement(firstNum, secondNum); + } + + return new RuleCaseElement(csepart); + } else { + return new LiteralCaseElement(csepart); + } + } + + @Override + public int hashCode() { + final int prime = 31; + int result = 1; + result = prime * result + ((type == null) ? 0 : type.hashCode()); + return result; + } + + @Override + public boolean equals(Object obj) { + if (this == obj) + return true; + if (obj == null) + return false; + if (getClass() != obj.getClass()) + return false; + CaseElement other = (CaseElement) obj; + if (type != other.type) + return false; + return true; + } +}
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