添加项目文件。

CompilerDesignIflr1/if-grammar.grammar

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+@top Program {
+  StatementList
+}
+
+StatementList {
+  Statement*
+}
+
+@skip { Whitespace }
+
+IfStatement {
+  If LParen ConditionalExpression RParen PartIfStatement Else Statement | If LParen ConditionalExpression RParen Statement
+}
+
+PartIfStatement {
+  If LParen ConditionalExpression RParen PartIfStatement Else PartIfStatement | NoIfStatement
+}
+
+ConditionalExpression {
+  Expression Operator Expression | Expression
+}
+
+Expression {
+  Term (AddLike Term)*
+}
+
+Statement {
+  IfStatement | NoIfStatement
+}
+
+NoIfStatement {
+  AssignmentStatement Semicolon | VariableDefinition Semicolon | LBrace Statement* RBrace | ConstantDefinition Semicolon
+}
+
+AssignmentStatement {
+  Identifier Equal Expression
+}
+
+Term {
+  Factor (MultiplyLike Factor)*
+}
+
+VariableDefinition {
+  Type (Identifier | Identifier Equal Expression)+
+}
+
+ConstantDefinition {
+  Const VariableDefinition
+}
+
+Type {
+  Int | Char
+}
+
+Factor {
+  Identifier | Number | Character | LParen Expression RParen
+}
+
+AddLike {
+  Plus | Minus
+}
+
+MultiplyLike {
+  Multiply | Divide | Modulo
+}
+
+Number {
+  UnsignedNumber | Minus UnsignedNumber | Plus UnsignedNumber
+}
+@tokens {
+  If { "!if" }
+  Else { "!else" }
+  Int {"!int"}
+  Char {"!char"}
+  Const { "!const" }
+  Plus { "+" }
+  Minus { "-" }
+  Multiply { "*" }
+  Modulo { "%" }
+  Divide { "/" }
+  LParen { "(" }
+  RParen { ")" }
+  LBrace { "{" }
+  RBrace { "}" }
+  Semicolon { ";" }
+  Identifier { $[a-zA-Z_]$[a-zA-Z0-9_]* } 
+  UnsignedNumber { $[0-9]+ }
+  String { "\"" $[\x00-\x7F]* "\"" }
+  Character { "'" $[\x00-\x7F] "'" }
+  Operator { "==" | "!=" | "<=" | ">=" | "<" | ">" }
+  Equal { "=" }
+  Whitespace { $[\t\n\r]+ }
+}