Annotation of parser3/src/types/pa_value.h, revision 1.109.6.1
1.22 paf 1: /** @file
1.24 paf 2: Parser: Value, Method, Junction class decls.
3:
1.109 paf 4: Copyright (c) 2001, 2003 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:
1.109.6.1! paf 11: static const char* IDENT_VALUE_H="$Date: 2003/01/21 15:51:17 $";
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
1.108 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;
1.107 paf 111:
112: /// extract VStateless_class
113: virtual VStateless_class *get_last_derived_class() {
114: return get_class();
115: };
1.108 paf 116: /// extract base object or class of Value, if any
117: virtual Value *base() { bark("(%s) has can not have base"); return 0; }
1.32 paf 118:
1.106 paf 119: /// extract VTable
1.35 paf 120: virtual Table *get_table() { return 0; }
1.1 paf 121:
122: public: // usage
123:
1.84 paf 124: Value(Pool& apool) : Pooled(apool) {
1.68 parser 125: }
1.1 paf 126:
1.26 paf 127: /// @return sure String. if it doesn't have string value barks
1.1 paf 128: const String& as_string() {
129: const String *result=get_string();
130: if(!result)
1.35 paf 131: bark("(%s) has no string representation");
1.6 paf 132:
1.1 paf 133: return *result;
134: }
135:
1.6 paf 136: protected:
1.1 paf 137:
1.22 paf 138: /// throws exception specifying bark-reason and name() type() of problematic value
1.109.6.1! paf 139: void bark(const char *reason,
1.65 parser 140: const char *alt_reason=0, const String *problem_source=0) const {
1.80 paf 141: throw Exception("parser.runtime",
1.84 paf 142: problem_source,
143: alt_reason?alt_reason:reason, type());
1.1 paf 144: }
145:
1.17 paf 146: };
147:
1.23 paf 148: /** \b junction is some code joined with context of it's evaluation.
1.22 paf 149:
150: there are code-junctions and method-junctions
151: - code-junctions are used when some parameter passed in cury brackets
152: - method-junctions used in ^method[] calls or $method references
1.99 paf 153:
154: Junctions register themselves in method_frame [if any] for consequent invalidation.
155: This prevents evaluation of junctions in outdated context
156:
157: To stop situations like this:
158: @code
159: @main[]
160: ^method1[]
161: ^method2[]
162:
163: @method1[]
164: $junction{
165: some code
166: }
167:
168: @method2[]
169: ^junction[]
170: @endcode
171:
1.101 paf 172: On wcontext[most dynamic context of all] scope exit (WContext::~WContext()) got cleaned -
173: Junction::wcontext becomes WContext.fparent (if any),
174: or Junction::method_frame becomes 0 (if no parent), which later in Request::process triggers exception
175:
176: parent changing helps ^switch implementation to remain simple
1.22 paf 177: */
1.17 paf 178: class Junction : public Pooled {
179: public:
180:
181: Junction(Pool& apool,
1.104 paf 182: Value& aself,
1.103 paf 183: const Method *amethod,
1.99 paf 184: VMethodFrame *amethod_frame,
1.17 paf 185: Value *arcontext,
186: WContext *awcontext,
1.99 paf 187: const Array *acode);
1.81 paf 188:
1.100 paf 189: void reattach(WContext *new_wcontext);
1.17 paf 190:
1.105 paf 191: /// always present
1.104 paf 192: Value& self;
1.22 paf 193: //@{
194: /// @name either these // so called 'method-junction'
1.103 paf 195: const Method *method;
1.22 paf 196: //@}
197: //@{
198: /// @name or these are present // so called 'code-junction'
1.99 paf 199: VMethodFrame *method_frame;
1.17 paf 200: Value *rcontext;
201: WContext *wcontext;
202: const Array *code;
1.22 paf 203: //@}
1.48 paf 204: };
205:
206: /**
207: native code method
208: params can be NULL when
1.53 paf 209: method min&max params (see VStateless_class::add_native_method)
1.48 paf 210: counts are zero.
211: */
1.39 paf 212: typedef void (*Native_code_ptr)(Request& request,
213: const String& method_name,
1.48 paf 214: MethodParams *params);
1.39 paf 215:
1.23 paf 216: /**
1.22 paf 217: class method.
218:
219: methods can have
220: - named or
221: - numbered parameters
222:
223: methods can be
224: - parser or
225: - native onces
226:
1.40 paf 227: holds
1.22 paf 228: - parameter names or number limits
229: - local names
230: - code [parser or native]
231: */
1.17 paf 232: class Method : public Pooled {
233: public:
1.39 paf 234:
1.41 paf 235: /// allowed method call types
1.39 paf 236: enum Call_type {
1.41 paf 237: CT_ANY, ///< method can be called either statically or dynamically
238: CT_STATIC, ///< method can be called only statically
239: CT_DYNAMIC ///< method can be called only dynamically
1.39 paf 240: };
241:
242: /// name for error reporting
1.17 paf 243: const String& name;
1.39 paf 244: ///
245: Call_type call_type;
1.22 paf 246: //@{
247: /// @name either numbered params // for native-code methods = operators
1.17 paf 248: int min_numbered_params_count, max_numbered_params_count;
1.22 paf 249: //@}
250: //@{
251: /// @name or named params&locals // for parser-code methods
1.17 paf 252: Array *params_names; Array *locals_names;
1.22 paf 253: //@}
254: //@{
255: /// @name the Code
1.17 paf 256: const Array *parser_code;/*OR*/Native_code_ptr native_code;
1.22 paf 257: //@}
1.17 paf 258:
259: Method(
260: Pool& apool,
261: const String& aname,
1.39 paf 262: Call_type call_type,
1.17 paf 263: int amin_numbered_params_count, int amax_numbered_params_count,
264: Array *aparams_names, Array *alocals_names,
265: const Array *aparser_code, Native_code_ptr anative_code) :
266:
267: Pooled(apool),
268: name(aname),
1.39 paf 269: call_type(call_type),
1.17 paf 270: min_numbered_params_count(amin_numbered_params_count),
271: max_numbered_params_count(amax_numbered_params_count),
272: params_names(aparams_names), locals_names(alocals_names),
273: parser_code(aparser_code), native_code(anative_code) {
274: }
275:
1.22 paf 276: /// call this before invoking to ensure proper actual numbered params count
1.75 parser 277: void check_actual_numbered_params(
1.104 paf 278: Value& self, const String& actual_name, Array *actual_numbered_params) const;
1.86 paf 279: };
280:
281: /// Auto-object used for temporarily substituting/removing elements
282: class Temp_value_element {
283: Value& fwhere;
284: const String& fname;
285: Value *saved;
286: public:
287: Temp_value_element(Value& awhere, const String& aname, Value *awhat) :
288: fwhere(awhere),
289: fname(aname),
1.108 paf 290: saved(awhere.get_element(aname, awhere, false)) {
1.93 paf 291: fwhere.put_element(aname, awhat, false);
1.86 paf 292: }
293: ~Temp_value_element() {
1.93 paf 294: fwhere.put_element(fname, saved, false);
1.86 paf 295: }
1.1 paf 296: };
297:
298: #endif
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