graphvizAbstractTree in the C and Python runtimes

src/runtime/c/Makefile.am

@@ -47,6 +47,7 @@ pgfinclude_HEADERS = \
 	pgf/parser.h \
 	pgf/lexer.h \
 	pgf/literals.h \
+	pgf/graphviz.h \
 	pgf/pgf.h
 
 libgu_la_SOURCES = \
@@ -115,6 +116,7 @@ libpgf_la_SOURCES = \
 	pgf/linearizer.c \
 	pgf/reasoner.c \
 	pgf/printer.c \
+	pgf/graphviz.c \
 	pgf/pgf.c \
 	pgf/pgf.h
 

src/runtime/c/pgf/graphviz.c

@@ -0,0 +1,93 @@
+#include "data.h"
+#include "graphviz.h"
+
+static int
+pgf_graphviz_abstract_tree_(PgfExpr expr, int *pid,
+                            GuWriter* wtr, GuExn* err)
+{
+	int id = -1;
+
+	GuVariantInfo ei = gu_variant_open(expr);
+	switch (ei.tag) {
+	case PGF_EXPR_ABS:
+		gu_impossible();
+		break;
+	case PGF_EXPR_APP: {
+		PgfExprApp* app = ei.data;
+		id = pgf_graphviz_abstract_tree_(app->fun, pid, wtr, err);
+		int arg_id = pgf_graphviz_abstract_tree_(app->arg, pid, wtr, err);
+		gu_printf(wtr, err, "n%d -- n%d [style = \"solid\"]\n", id, arg_id);
+		break;
+	}
+	case PGF_EXPR_LIT: {
+		PgfExprLit* lit = ei.data;
+		id = (*pid)++;
+		gu_printf(wtr, err, "n%d[label = \"", id);
+		
+		GuVariantInfo ei = gu_variant_open(lit->lit);
+		switch (ei.tag) {
+		case PGF_LITERAL_STR: {
+			PgfLiteralStr* lit = ei.data;
+			gu_puts("\\\"", wtr, err);
+			gu_string_write(lit->val, wtr, err);
+			gu_puts("\\\"", wtr, err);
+			break;
+		}
+		case PGF_LITERAL_INT: {
+			PgfLiteralInt* lit = ei.data;
+			gu_printf(wtr, err, "%d", lit->val);
+			break;
+		}
+		case PGF_LITERAL_FLT: {
+			PgfLiteralFlt* lit = ei.data;
+			gu_printf(wtr, err, "%lf", lit->val);
+			break;
+		}
+		default:
+			gu_impossible();
+		}
+
+		gu_puts("\", style = \"solid\", shape = \"plaintext\"]\n", wtr, err);
+		break;
+	}
+	case PGF_EXPR_META:
+		id = (*pid)++;
+		gu_printf(wtr, err, "n%d[label = \"?\", style = \"solid\", shape = \"plaintext\"]\n", id);
+		break;
+	case PGF_EXPR_FUN: {
+		PgfExprFun* fun = ei.data;
+		id = (*pid)++;
+		gu_printf(wtr, err, "n%d[label = \"", id);
+		gu_string_write(fun->fun, wtr, err);
+		gu_puts("\", style = \"solid\", shape = \"plaintext\"]\n", wtr, err);
+		break;
+	}
+	case PGF_EXPR_VAR:
+		gu_impossible();
+		break;
+	case PGF_EXPR_TYPED: {
+		PgfExprTyped* typed = ei.data;
+		id = pgf_graphviz_abstract_tree_(typed->expr, pid, wtr, err);
+		break;
+	}
+	case PGF_EXPR_IMPL_ARG: {
+		PgfExprImplArg* implarg = ei.data;
+		id = pgf_graphviz_abstract_tree_(implarg->expr, pid, wtr, err);
+		break;
+	}
+	default:
+		gu_impossible();
+	}
+
+	return id;
+}
+
+void
+pgf_graphviz_abstract_tree(PgfExpr expr, GuWriter* wtr, GuExn* err)
+{
+	int id = 0;
+
+	gu_puts("graph {\n", wtr, err);
+	pgf_graphviz_abstract_tree_(expr, &id, wtr, err);
+	gu_puts("}", wtr, err);
+}

src/runtime/c/pgf/graphviz.h

@@ -0,0 +1,7 @@
+#ifndef PGF_GRAPHVIZ_H_
+#define PGF_GRAPHVIZ_H_
+
+void
+pgf_graphviz_abstract_tree(PgfExpr expr, GuWriter* wtr, GuExn* err);
+
+#endif

src/runtime/c/utils/pgf-service.c

@@ -55,87 +55,6 @@ url_escape(char *str)
     *pw++ = 0;
 }
 
-static int
-generate_graphviz_expr(PgfExpr expr, int *pid,
-                       GuWriter* wtr, GuExn* err, GuPool* pool)
-{
-	int id = -1;
-	
-	GuVariantInfo ei = gu_variant_open(expr);
-	switch (ei.tag) {
-	case PGF_EXPR_FUN: {
-		PgfExprFun* fun = ei.data;
-		id = (*pid)++;
-		gu_printf(wtr, err, "n%d[label = \"", id);
-		gu_string_write(fun->fun, wtr, err);
-		gu_puts("\", style = \"solid\", shape = \"plaintext\"]\n", wtr, err);
-		break;
-	}
-	case PGF_EXPR_APP: {
-		PgfExprApp* app = ei.data;
-		id = generate_graphviz_expr(app->fun, pid, wtr, err, pool);
-		int arg_id = generate_graphviz_expr(app->arg, pid, wtr, err, pool);
-		gu_printf(wtr, err, "n%d -- n%d [style = \"solid\"]\n", id, arg_id);
-		break;
-	}
-	case PGF_EXPR_ABS:
-	case PGF_EXPR_LIT: {
-		PgfExprLit* lit = ei.data;
-		id = (*pid)++;
-		gu_printf(wtr, err, "n%d[label = \"", id);
-		
-		GuVariantInfo ei = gu_variant_open(lit->lit);
-		switch (ei.tag) {
-		case PGF_LITERAL_STR: {
-			PgfLiteralStr* lit = ei.data;
-			gu_puts("\\\"", wtr, err);
-			gu_string_write(lit->val, wtr, err);
-			gu_puts("\\\"", wtr, err);
-			break;
-		}
-		case PGF_LITERAL_INT: {
-			PgfLiteralInt* lit = ei.data;
-			gu_printf(wtr, err, "%d", lit->val);
-			break;
-		}
-		case PGF_LITERAL_FLT: {
-			PgfLiteralFlt* lit = ei.data;
-			gu_printf(wtr, err, "%lf", lit->val);
-			break;
-		}
-		default:
-			gu_impossible();
-		}
-
-		gu_puts("\", style = \"solid\", shape = \"plaintext\"]\n", wtr, err);
-		break;
-	}
-	case PGF_EXPR_META:
-		id = (*pid)++;
-		gu_printf(wtr, err, "n%d[label = \"?\", style = \"solid\", shape = \"plaintext\"]\n", id);
-		break;
-	case PGF_EXPR_VAR:
-	case PGF_EXPR_TYPED:
-	case PGF_EXPR_IMPL_ARG:
-		gu_impossible();
-		break;
-	default:
-		gu_impossible();
-	}
-	
-	return id;
-}
-
-static void
-generate_graphviz(PgfExpr expr, GuWriter* wtr, GuExn* err, GuPool* pool)
-{
-	int id = 0;
-
-	gu_puts("graph {\n", wtr, err);
-	generate_graphviz_expr(expr, &id, wtr, err, pool);
-	gu_puts("}", wtr, err);
-}
-
 static int
 render(PgfExpr expr, GuPool* pool)
 {
@@ -175,7 +94,7 @@ render(PgfExpr expr, GuPool* pool)
 		GuWriter* wtr = gu_new_utf8_writer(out, pool);
 		GuExn* err = gu_new_exn(NULL, gu_kind(type), pool);
 
-		generate_graphviz(expr, wtr, err, pool);
+		pgf_graphviz_abstract_tree(expr, wtr, err);
 		fclose(fstream);
 
 		close(cp[1]);

src/runtime/python/pypgf.c

@@ -2215,6 +2215,30 @@ pgf_readType(PyObject *self, PyObject *args) {
     return pytype;
 }
 
+static PyObject*
+pgf_graphvizAbstractTree(PyObject *self, PyObject *args) {
+	ExprObject* pyexpr;
+	if (!PyArg_ParseTuple(args, "O!", &pgf_ExprType, &pyexpr))
+        return NULL;
+
+	GuPool* tmp_pool = gu_local_pool();
+	GuExn* err = gu_new_exn(NULL, gu_kind(type), tmp_pool);
+	GuStringBuf* sbuf = gu_string_buf(tmp_pool);
+	GuWriter* wtr = gu_string_buf_writer(sbuf);
+	
+	pgf_graphviz_abstract_tree(pyexpr->expr, wtr, err);
+	if (!gu_ok(err)) {
+		PyErr_SetString(PGFError, "The abstract tree cannot be visualized");
+		return NULL;
+	}
+
+	GuString str = gu_string_buf_freeze(sbuf, tmp_pool);
+	PyObject* pystr = gu2py_string(str);
+
+	gu_pool_free(tmp_pool);
+	return pystr;
+}
+
 static PyMethodDef module_methods[] = {
     {"readPGF",  (void*)pgf_readPGF,  METH_VARARGS,
      "Reads a PGF file in memory"},
@@ -2222,6 +2246,8 @@ static PyMethodDef module_methods[] = {
      "Parses a string as an abstract tree"},
     {"readType", (void*)pgf_readType, METH_VARARGS,
      "Parses a string as an abstract type"},
+    {"graphvizAbstractTree", (void*)pgf_graphvizAbstractTree, METH_VARARGS,
+     "Renders an abstract syntax tree in a Graphviz format"},
     {NULL, NULL, 0, NULL}        /* Sentinel */
 };