Annotation of parser3/src/types/pa_value.h, revision 1.106
1.22 paf 1: /** @file
1.24 paf 2: Parser: Value, Method, Junction class decls.
3:
1.78 paf 4: Copyright (c) 2001, 2002 ArtLebedev Group (http://www.artlebedev.com)
1.79 paf 5: Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
1.1 paf 6: */
7:
8: #ifndef PA_VALUE_H
9: #define PA_VALUE_H
1.87 paf 10:
1.106 ! paf 11: static const char* IDENT_VALUE_H="$Date: 2002/09/17 17:14:32 $";
1.1 paf 12:
13: #include "pa_pool.h"
14: #include "pa_string.h"
15: #include "pa_array.h"
16: #include "pa_exception.h"
1.13 paf 17: #include "pa_globals.h"
1.1 paf 18:
1.99 paf 19: // forwards
20:
1.9 paf 21: class VStateless_class;
1.1 paf 22: class WContext;
23: class Request;
1.35 paf 24: class Table;
1.17 paf 25: class Junction;
26: class Method;
1.20 paf 27: class Hash;
1.42 paf 28: class VFile;
1.64 parser 29: class MethodParams;
1.93 paf 30: class VObject;
1.99 paf 31: class VMethodFrame;
1.1 paf 32:
1.31 paf 33: /// grandfather of all @a values in @b Parser
1.1 paf 34: class Value : public Pooled {
35: public: // Value
36:
1.106 ! paf 37: /// value type, used for error reporting and 'is' expression operator
1.1 paf 38: virtual const char *type() const =0;
1.89 paf 39:
1.91 paf 40: /** remember derived class instance
41: - VObject: the only client
42: */
1.93 paf 43: virtual VObject *set_derived(VObject * /*aderived*/) { return 0; }
1.91 paf 44:
1.89 paf 45: /**
1.95 paf 46: all except VObject/VClass: this if @atype eq type()
47: VObject/VClass: can locate parent class by it's type
1.89 paf 48: */
1.96 paf 49: virtual Value *as(const char *atype, bool looking_up) {
50: return atype && strcmp(type(), atype)==0?this:0;
1.89 paf 51: }
1.97 paf 52: /// type checking helper, uses Value::as
53: bool is(const char *atype) { return as(atype, false)!=0; }
1.59 parser 54:
1.106 ! paf 55: /// is this value defined?
1.38 paf 56: virtual bool is_defined() const { return true; }
1.59 parser 57:
1.106 ! paf 58: /// is this value string?
1.38 paf 59: virtual bool is_string() const { return false; }
1.59 parser 60:
1.106 ! paf 61: /// what's the meaning of this value in context of expression?
1.75 parser 62: virtual Value *as_expr_result(bool /*return_string_as_is*/=false) {
1.34 paf 63: bark("(%s) can not be used in expression"); return 0;
64: }
1.59 parser 65:
1.106 ! paf 66: /// extract Hash
1.76 parser 67: virtual Hash *get_hash(const String * /*source*/) { return 0; }
1.59 parser 68:
1.106 ! paf 69: /// extract const String
1.1 paf 70: virtual const String *get_string() { return 0; }
1.59 parser 71:
1.106 ! paf 72: /// extract double
1.72 parser 73: virtual double as_double() const { bark("(%s) does not have numerical (double) value"); return 0; }
1.59 parser 74:
1.106 ! paf 75: /// extract integer
1.72 parser 76: virtual int as_int () const { bark("(%s) does not have numerical (int) value"); return 0; }
1.59 parser 77:
1.106 ! paf 78: /// extract bool
1.72 parser 79: virtual bool as_bool() const { bark("(%s) does not have logical value"); return 0; }
1.59 parser 80:
1.106 ! paf 81: /// extract file
1.75 parser 82: virtual VFile *as_vfile(String::Untaint_lang /*lang*/=String::UL_UNSPECIFIED,
83: bool /*origins_mode*/=false) {
1.42 paf 84: bark("(%s) does not have file value"); return 0;
85: }
1.59 parser 86:
1.106 ! paf 87: /// extract Junction
1.1 paf 88: virtual Junction *get_junction() { return 0; }
1.59 parser 89:
1.93 paf 90: /** extract base object of Value
91: @return for
92: - VObject: fbase
93: */
94: virtual Value *base_object() { bark("(%s) has no base object"); return 0; }
95:
1.106 ! paf 96: /// extract Value element
1.95 paf 97: virtual Value *get_element(const String& /*aname*/, Value * /*aself*/, bool /*looking_up*/) { bark("(%s) has no elements"); return 0; }
1.92 paf 98:
1.106 ! paf 99: /// store Value element under @a name
1.93 paf 100: virtual bool put_element(const String& name, Value * /*value*/, bool /*replace*/) {
1.65 parser 101: // to prevent modification of system classes,
102: // created at system startup, and not having exception
103: // handler installed, we neet to bark using request.pool
104: bark("(%s) does not accept elements",
105: "element can not be stored to %s", &name);
1.93 paf 106: return false;
1.65 parser 107: }
1.59 parser 108:
1.106 ! paf 109: /// extract VStateless_class
1.85 paf 110: virtual VStateless_class *get_class()=0;
1.32 paf 111:
1.106 ! paf 112: /// extract VTable
1.35 paf 113: virtual Table *get_table() { return 0; }
1.1 paf 114:
115: public: // usage
116:
1.84 paf 117: Value(Pool& apool) : Pooled(apool) {
1.68 parser 118: }
1.1 paf 119:
1.26 paf 120: /// @return sure String. if it doesn't have string value barks
1.1 paf 121: const String& as_string() {
122: const String *result=get_string();
123: if(!result)
1.35 paf 124: bark("(%s) has no string representation");
1.6 paf 125:
1.1 paf 126: return *result;
127: }
128:
1.6 paf 129: protected:
1.1 paf 130:
1.22 paf 131: /// throws exception specifying bark-reason and name() type() of problematic value
1.65 parser 132: void bark(char *reason,
133: const char *alt_reason=0, const String *problem_source=0) const {
1.80 paf 134: throw Exception("parser.runtime",
1.84 paf 135: problem_source,
136: alt_reason?alt_reason:reason, type());
1.1 paf 137: }
138:
1.17 paf 139: };
140:
1.23 paf 141: /** \b junction is some code joined with context of it's evaluation.
1.22 paf 142:
143: there are code-junctions and method-junctions
144: - code-junctions are used when some parameter passed in cury brackets
145: - method-junctions used in ^method[] calls or $method references
1.99 paf 146:
147: Junctions register themselves in method_frame [if any] for consequent invalidation.
148: This prevents evaluation of junctions in outdated context
149:
150: To stop situations like this:
151: @code
152: @main[]
153: ^method1[]
154: ^method2[]
155:
156: @method1[]
157: $junction{
158: some code
159: }
160:
161: @method2[]
162: ^junction[]
163: @endcode
164:
1.101 paf 165: On wcontext[most dynamic context of all] scope exit (WContext::~WContext()) got cleaned -
166: Junction::wcontext becomes WContext.fparent (if any),
167: or Junction::method_frame becomes 0 (if no parent), which later in Request::process triggers exception
168:
169: parent changing helps ^switch implementation to remain simple
1.22 paf 170: */
1.17 paf 171: class Junction : public Pooled {
172: public:
173:
174: Junction(Pool& apool,
1.104 paf 175: Value& aself,
1.103 paf 176: const Method *amethod,
1.99 paf 177: VMethodFrame *amethod_frame,
1.17 paf 178: Value *arcontext,
179: WContext *awcontext,
1.99 paf 180: const Array *acode);
1.81 paf 181:
1.100 paf 182: void reattach(WContext *new_wcontext);
1.17 paf 183:
1.105 paf 184: /// always present
1.104 paf 185: Value& self;
1.22 paf 186: //@{
187: /// @name either these // so called 'method-junction'
1.103 paf 188: const Method *method;
1.22 paf 189: //@}
190: //@{
191: /// @name or these are present // so called 'code-junction'
1.99 paf 192: VMethodFrame *method_frame;
1.17 paf 193: Value *rcontext;
194: WContext *wcontext;
195: const Array *code;
1.22 paf 196: //@}
1.48 paf 197: };
198:
199: /**
200: native code method
201: params can be NULL when
1.53 paf 202: method min&max params (see VStateless_class::add_native_method)
1.48 paf 203: counts are zero.
204: */
1.39 paf 205: typedef void (*Native_code_ptr)(Request& request,
206: const String& method_name,
1.48 paf 207: MethodParams *params);
1.39 paf 208:
1.23 paf 209: /**
1.22 paf 210: class method.
211:
212: methods can have
213: - named or
214: - numbered parameters
215:
216: methods can be
217: - parser or
218: - native onces
219:
1.40 paf 220: holds
1.22 paf 221: - parameter names or number limits
222: - local names
223: - code [parser or native]
224: */
1.17 paf 225: class Method : public Pooled {
226: public:
1.39 paf 227:
1.41 paf 228: /// allowed method call types
1.39 paf 229: enum Call_type {
1.41 paf 230: CT_ANY, ///< method can be called either statically or dynamically
231: CT_STATIC, ///< method can be called only statically
232: CT_DYNAMIC ///< method can be called only dynamically
1.39 paf 233: };
234:
235: /// name for error reporting
1.17 paf 236: const String& name;
1.39 paf 237: ///
238: Call_type call_type;
1.22 paf 239: //@{
240: /// @name either numbered params // for native-code methods = operators
1.17 paf 241: int min_numbered_params_count, max_numbered_params_count;
1.22 paf 242: //@}
243: //@{
244: /// @name or named params&locals // for parser-code methods
1.17 paf 245: Array *params_names; Array *locals_names;
1.22 paf 246: //@}
247: //@{
248: /// @name the Code
1.17 paf 249: const Array *parser_code;/*OR*/Native_code_ptr native_code;
1.22 paf 250: //@}
1.17 paf 251:
252: Method(
253: Pool& apool,
254: const String& aname,
1.39 paf 255: Call_type call_type,
1.17 paf 256: int amin_numbered_params_count, int amax_numbered_params_count,
257: Array *aparams_names, Array *alocals_names,
258: const Array *aparser_code, Native_code_ptr anative_code) :
259:
260: Pooled(apool),
261: name(aname),
1.39 paf 262: call_type(call_type),
1.17 paf 263: min_numbered_params_count(amin_numbered_params_count),
264: max_numbered_params_count(amax_numbered_params_count),
265: params_names(aparams_names), locals_names(alocals_names),
266: parser_code(aparser_code), native_code(anative_code) {
267: }
268:
1.22 paf 269: /// call this before invoking to ensure proper actual numbered params count
1.75 parser 270: void check_actual_numbered_params(
1.104 paf 271: Value& self, const String& actual_name, Array *actual_numbered_params) const;
1.86 paf 272: };
273:
274: /// Auto-object used for temporarily substituting/removing elements
275: class Temp_value_element {
276: Value& fwhere;
277: const String& fname;
278: Value *saved;
279: public:
280: Temp_value_element(Value& awhere, const String& aname, Value *awhat) :
281: fwhere(awhere),
282: fname(aname),
1.94 paf 283: saved(awhere.get_element(aname, &awhere, false)) {
1.93 paf 284: fwhere.put_element(aname, awhat, false);
1.86 paf 285: }
286: ~Temp_value_element() {
1.93 paf 287: fwhere.put_element(fname, saved, false);
1.86 paf 288: }
1.1 paf 289: };
290:
291: #endif
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