Formal grammar for arithmetic expressions (coNCePTuaL User’s Guide)

Formal grammar for arithmetic expressions

Formal grammar for arithmetic expressions

For completeness, the following productions formalize the process by which coNCePTuaL parses arithmetic expressions:

<expr>

::=

<cond_expr>

<cond_expr> ::= <add_expr> IF <rel_expr> OTHERWISE <add_expr>

<`add_expr`>	::=	<`mult_expr`>
	\|	<`add_expr`> ‘`+`’ <`mult_expr`>
	\|	<`add_expr`> ‘`-`’ <`mult_expr`>
	\|	<`add_expr`> ‘`\|`’ <`mult_expr`>
	\|	<`add_expr`> `XOR` <`mult_expr`>

<`mult_expr`>	::=	<`unary_expr`>
	\|	<`mult_expr`> ‘`*`’ <`unary_expr`>
	\|	<`mult_expr`> ‘`/`’ <`unary_expr`>
	\|	<`mult_expr`> `MOD` <`unary_expr`>
	\|	<`mult_expr`> ‘`>>`’ <`unary_expr`>
	\|	<`mult_expr`> ‘`<<`’ <`unary_expr`>
	\|	<`mult_expr`> ‘`&`’ <`unary_expr`>

<power_expr>

::=

<primary_expr> [‘**’ <unary_expr>]

<`unary_expr`>	::=	<`power_expr`>
	\|	<`unary_operator`> <`unary_expr`>

<unary_operator> ::= ‘+’ | ‘-’ | NOT

<`primary_expr`>	::=	‘`(`’ <`expr`> ‘`)`’
	\|	<`ident`>
	\|	<`integer`>
	\|	<`func_name`> ‘`(`’ <`enumerated_exprs`> ‘`)`’
	\|	`REAL` ‘`(`’ <`expr`> ‘`)`’

<enumerated_exprs>

::=

<expr> [‘,’ <expr>]*

Scott Pakin, pakin@lanl.gov