<parser>

A sample XML for <parser> section looks like:

<parser start="program">
    <type format="((Node){0})">stmt expr stmt_list</type>
    <type format="((String){0})">VARIABLE</type>
    <type format="((Integer){0})">INTEGER</type>
    <grammar rule="program">
        <rhs>function</rhs>
        <action>return 0;</action>
    </grammar>
    <grammar rule="function">
        <rhs>function stmt</rhs>
        <action>interpret ($2);</action>
        <rhs></rhs>
    </grammar>
    <grammar rule="stmt">
        <rhs>';'</rhs>
        <action>$$ = new SemiColonNode ();</action>

        <rhs>expr ';'</rhs>
        <action>$$ = $1;</action>

        <rhs>PRINT expr ';'</rhs>
        <action>$$ = new PrintNode ($2);</action>

        <rhs>VARIABLE '=' expr ';'</rhs>
        <action>$$ = new AssignNode ($1, $3);</action>

        <rhs>WHILE '(' expr ')' stmt</rhs>
        <action>$$ = new WhileNode ($3, $5);</action>

        <rhs precedence="IFX">IF '(' expr ')' stmt</rhs>
        <action>$$ = new IfNode ($3, $5, null);</action>

        <rhs>IF '(' expr ')' stmt ELSE stmt</rhs>
        <action>$$ = new IfNode ($3, $5, $7);</action>

        <rhs>'{' stmt_list '}'</rhs>
        <action>$$ = $2;</action>
    </grammar>
</parser>

Options for the parser are specified as attributes of the <parser> tag.

Attribute	Description
start	Specify the start non-terminal. If this attribute is not specified, the LHS of the first grammar is used.
recovery	Should the parser try to generate error recovery routines. This attribute is default true. Set this attribute to false for speedy exit from the parser in case of error.
parseerror	Should the parser generate the error function since the user is going to supply one. This attribute is default true.

See the parser recovery page for more information on error recovery.

<type>

This tag is used to specify the necessary code that should be used to cast / retrieve members of arguments {0}. In the example above, $1 was automatically converted to ((Node)$1) if $1 is a stmt, expr, or stmt_list. $1 itself is internally translated to the appropriate variable/function call.

(Note in the Java code generator, the format does not apply to $$).

<grammar>

The attribute value of rule is a non-terminal. All the productions in <rhs> are for this particular terminal.

<rhs>

This tag represents the production for the non-terminal of the parent grammar tag. Its action code should be immediately followed. If not, there are no actions performed for this particular production.

The attributes for the rhs tag are

Attribute	Description
precedence	Specify the precedence for the production to the precedence of a particular terminal.

<action>

This tag is used to specify the code that should be called for the production in the immediate <rhs> above.

$$ represents the value for the LHS non-terminal. $1, $2 etc represent the object values of the symbols at the position for productions specified in the <lhs> tag, starting from 1.