#include "environment.hh"
#include "errormsg.hh"
#include "boxes.hh"
#include "ppbox.hh"
#include "names.hh"

Include dependency graph for environment.cpp:

Functions
static Tree	pushNewLayer (Tree lenv)
	Push a new (unique) empty layer (where multiple definitions can be stored) on top of an existing environment. More...

Tree	pushEnvBarrier (Tree lenv)

bool	isEnvBarrier (Tree lenv)
	Test if the environment is a barrier (or nil) so that searchIdDef will know where to stop when searching an environment. More...

static void	addLayerDef (Tree id, Tree def, Tree lenv)
	Add a definition (as a property) to the current top level layer. More...

Tree	pushValueDef (Tree id, Tree def, Tree lenv)
	Push a new layer and add a single definition. More...

Tree	pushMultiClosureDefs (Tree ldefs, Tree visited, Tree lenv)
	Push a new layer with multiple definitions creating the appropriate closures. More...

bool	searchIdDef (Tree id, Tree &def, Tree lenv)
	Search the environment (until first barrier) for the definition of a symbol ID and return it. More...

static void	updateClosures (vector< Tree > &clos, Tree oldEnv, Tree newEnv)
	Replace closure that point to oldEnv with closure on newEnv. More...

Tree	copyEnvReplaceDefs (Tree anEnv, Tree ldefs, Tree visited, Tree curEnv)
	Create a new environment by copying an existing one and replacing some definitions. More...

Variables
Sym	BARRIER = symbol ("BARRIER")
	Push a new environment barrier on top of an existing environment so that searchIdDef (used by the pattern matcher) will not look after the barrier. More...

Function Documentation

static void addLayerDef	(	Tree	id,
		Tree	def,
		Tree	lenv
	)

static

Add a definition (as a property) to the current top level layer.

Check and warn for multiple definitions.

Parameters

id	the symbol id to be defined
def	the definition to be binded to the symbol id
lenv	the environment where to add this new definition

Definition at line 69 of file environment.cpp.

References evalwarning(), gErrorCount, getDefFileProp(), getDefLineProp(), getProperty(), print(), and setProperty().

Referenced by pushMultiClosureDefs(), and pushValueDef().

 {
     // check for multiple definitions of a symbol in the same layer
     Tree olddef;
     if (getProperty(lenv, id, olddef)) {
         if (def == olddef) {
             evalwarning(getDefFileProp(id), getDefLineProp(id), "equivalent re-definitions of", id);
         } else {
             fprintf(stderr, "%s:%d: ERROR: redefinition of symbols are not allowed : ", getDefFileProp(id), getDefLineProp(id));
             print(id,stderr);
             fprintf(stderr, " is already defined in file \"%s\" line %d \n", getDefFileProp(id), getDefLineProp(id));
             gErrorCount++;
         }
     }
     setProperty(lenv, id, def);
 }

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Tree copyEnvReplaceDefs	(	Tree	anEnv,
		Tree	ldefs,
		Tree	visited,
		Tree	curEnv
	)

Create a new environment by copying an existing one and replacing some definitions.

Parameters

xenv	existing environment we will copy
ldefs	list of pairs (symbol id x definition) that will replace old definitions
visited	set of visited symbols (used for recursive definition detection)
lenv	the current environment to evaluate the definitions

Returns: the new environment

Definition at line 169 of file environment.cpp.

References CTree::branch(), closure(), CTree::exportProperties(), hd(), isBoxCase(), isNil(), nil, pushNewLayer(), setDefNameProperty(), setProperty(), tl(), and updateClosures().

Referenced by realeval().

 {
     vector<Tree>    ids, clos;
     Tree            copyEnv;
 
     anEnv->exportProperties(ids, clos);             // get the definitions of the environment
     copyEnv = pushNewLayer(anEnv->branch(0));       // create new environment with same stack
     updateClosures(clos, anEnv, copyEnv);           // update the closures replacing oldEnv with newEnv
 
     for (unsigned int i=0; i < clos.size(); i++) {           // transfers the updated definitions to the new environment
         setProperty(copyEnv, ids[i], clos[i]);
     }
 
     while (!isNil(ldefs)) {                         // replace the old definitions with the new ones
         Tree def = hd(ldefs);
         Tree id = hd(def);
         Tree rhs= tl(def);
         Tree cl = closure(rhs,nil,visited,curEnv);
         stringstream s; s << boxpp(id);
         if (!isBoxCase(rhs)) setDefNameProperty(cl,s.str());
         setProperty(copyEnv, id, cl);
         ldefs = tl(ldefs);
     }
     return copyEnv;
 }

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bool isEnvBarrier ( Tree lenv )

Test if the environment is a barrier (or nil) so that searchIdDef will know where to stop when searching an environment.

Parameters

lenv	the environment to test

Returns: true is barrier reached

Definition at line 56 of file environment.cpp.

References isNil(), and CTree::node().

Referenced by searchIdDef().

 {
     return isNil(lenv) || (lenv->node() == Node(BARRIER));
 }

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Tree pushEnvBarrier ( Tree lenv )

Definition at line 43 of file environment.cpp.

References tree().

Referenced by evalCase().

 {
     return tree(BARRIER, lenv);
 }

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Tree pushMultiClosureDefs	(	Tree	ldefs,
		Tree	visited,
		Tree	lenv
	)

Push a new layer with multiple definitions creating the appropriate closures.

Parameters

ldefs	list of pairs (symbol id x definition) to be binded to the symbol id
visited	set of visited symbols (used for recursive definition detection)
lenv	the environment where to push the layer and add all the definitions

Returns: the new environment

Definition at line 109 of file environment.cpp.

References addLayerDef(), closure(), hd(), isBoxCase(), isNil(), nil, pushNewLayer(), setDefNameProperty(), and tl().

Referenced by evaldocexpr(), evalprocess(), and realeval().

 {
     Tree lenv2 = pushNewLayer(lenv);
     while (!isNil(ldefs)) {
         Tree def = hd(ldefs);
         Tree id = hd(def);
         Tree rhs= tl(def);
         Tree cl = closure(tl(def),nil,visited,lenv2);
         stringstream s; s << boxpp(id);
         if (!isBoxCase(rhs)) setDefNameProperty(cl,s.str());
         addLayerDef( id, cl, lenv2 );
         ldefs = tl(ldefs);
     }
     return lenv2;
 }

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static Tree pushNewLayer ( Tree lenv )

static

Push a new (unique) empty layer (where multiple definitions can be stored) on top of an existing environment.

Parameters

lenv	the old environment

Returns: the new environment

Definition at line 26 of file environment.cpp.

References tree(), and unique().

Referenced by copyEnvReplaceDefs(), pushMultiClosureDefs(), and pushValueDef().

 {
     return tree(unique("ENV_LAYER"), lenv);
 }

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Tree pushValueDef	(	Tree	id,
		Tree	def,
		Tree	lenv
	)

Push a new layer and add a single definition.

Parameters

id	the symbol id to be defined
def	the definition to be binded to the symbol id
lenv	the environment where to push the layer and add the definition

Returns: the new environment

Definition at line 94 of file environment.cpp.

References addLayerDef(), and pushNewLayer().

Referenced by apply_pattern_matcher(), applyList(), iteratePar(), iterateProd(), iterateSeq(), iterateSum(), and real_a2sb().

 {
     Tree lenv2 = pushNewLayer(lenv);
     addLayerDef(id, def, lenv2);
     return lenv2;
 }

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bool searchIdDef	(	Tree	id,
		Tree &	def,
		Tree	lenv
	)

Search the environment (until first barrier) for the definition of a symbol ID and return it.

Used by the pattern matcher.

Parameters

id	the symbol ID to search
def	where to store the definition if any
lenv	the environment

Returns: true if a definition was found

Definition at line 135 of file environment.cpp.

References CTree::branch(), getProperty(), and isEnvBarrier().

Referenced by apply_pattern_matcher().

 {
     // search the environment until a definition is found
     // or a barrier (or nil) is reached
 
     while (!isEnvBarrier(lenv) && !getProperty(lenv, id, def)) {
         lenv = lenv->branch(0);
     }
     return !isEnvBarrier(lenv);
 }

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static void updateClosures	(	vector< Tree > &	clos,
		Tree	oldEnv,
		Tree	newEnv
	)

static

Replace closure that point to oldEnv with closure on newEnv.

Definition at line 149 of file environment.cpp.

References closure(), and isClosure().

Referenced by copyEnvReplaceDefs().

 {
     for (unsigned int i=0; i < clos.size(); i++) {
         Tree exp, genv, visited, lenv;
         if (isClosure(clos[i], exp, genv, visited, lenv)) {
             if (lenv == oldEnv) {
                 clos[i] = closure(exp, genv, visited, newEnv);
             }
         }
     }
 }

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Variable Documentation

Sym BARRIER = symbol ("BARRIER")

Push a new environment barrier on top of an existing environment so that searchIdDef (used by the pattern matcher) will not look after the barrier.

This barrier will not any influence on regular environment lookup.

Parameters

lenv	the old environment

Returns: the new environment

Definition at line 41 of file environment.cpp.

Functions

Variables

Function Documentation

Variable Documentation