Difference between revisions of "SCI/Specifications/SCI in action/Parser"

SCI/Specifications/SCI in action/Parser (view source)

Revision as of 03:55, 19 January 2009

348 bytes removed , 03:55, 19 January 2009

→‎Semantics: Fixed some pseudo code

Fingolfin

1,079

edits

@@ Line 301: / Line 301: @@
 Where S is the set of possible semantic values, and V is the set of non-terminals as defined in the grammar. We will also use the sequence <i>&gamma;<sub>0</sub>,&gamma<sub>1</sub>,&gamma<sub>2</sub> &hellip; &gamma<sub>k-1</sub></i> which will represent the word groups the input tokens belonged to (in the exact order they were accepted), and the sequence <i>r<sub>0</sub>,r<sub>1</sub>,r<sub>2</sub> &hellip; r<sub>l-1</sub></i> , which will be the list of rules used to create the left derivation tree as described in the previous section.
+<pre>
-<syntax type="?">
+  Helper function sci_said_recursive: S &times; V &times; (V &cup; &Sigma;)* &rarr; NODE
-              Helper function sci_said_recursive: S \times V \times (V \cup \Sigma)* \to \Node
+  Parameters: s &isin; S, Rule r &isin; V &times; (V &cup; &Sigma;): v0 &rarr; v1 v2 ... vi
-              Parameters: s \in S, Rule r \in V \times (V \cup \Sigma): v0 \to v1 v2 ... vi
+  cnmr = cnr
-              cnmr = cnr
+  NODE n := s, v0
-              \Node n := s, v0
+  FOR j := 1 TO i
-              FOR j := 1 TO i
+    IF (vj &isin; &Sigma;) THEN
-                        IF (vj \in \Sigma) THEN
+      n := n, &gamma;cn&gamma;
-                                n := n, \gammacn\gamma
+      cn&gamma; := cn&gamma; + 1
-                                cn\gamma := cn\gamma + 1
+    ELSE
-                        ELSE
+      cnoldr := cnr
-                                cnoldr := cnr
+      cnr := cnr + 1
-                                cnr := cnr + 1
+      n := n, sci_said_recursive(&Sigma;rmr,j, rcnoldr)
-                                n := n, sci_said_recursive(\sigmarmr,j, rcnoldr)
+    FI
-                        FI
+  ROF
-              ROF
+  RETURN (n)
-              RETURN (n)
+  Helper function get_children: NODE &rarr; NODE*
+          get_children((s, v, n0, n1 ... nm)) := n0, n1 ... nm
-              Helper function get_children: \Node \to \Node*
-                              get_children((s, v, n0, n1 ... nm)) := n0, n1 ... nm
+  Algorithm SCI-SAID-TREE
+  cn&gamma; := 0;
-              Algorithm SCI-SAID-TREE
+  cnr := 1;
-              cn\gamma := 0;
+  ntemp := ntemp, SCI-SAID-RECURSIVE(0, r0)
-              cnr := 1;
+  root(T&Pi;) := (141, 13f, get_children(ntemp))
-              ntemp := ntemp, SCI-SAID-RECURSIVE(0, r0)
+</pre>
-              root(T\Pi) := (141, 13f, get_children(ntemp))
-</syntax>
 Here is an example, based on the previous one: